United States

Environmental Protection

Agency

Solid Waste and

Emergency Response

(5102G)

EPA 542-B-99-003

June 1999

www.epa.gov/tio

clu-in.org

Phytoremediation Resource

Guide

EPA 542-B-99-003

June 1999

Phytoremediation Resource Guide

U.S. Environmental Protection Agency

Office of Solid Waste and Emergency Response

Technology Innovation Office

Washington, DC 20460
Notice

This resource guide was prepared by: Environmental Management Support, Inc., 8601 Georgia

Avenue, Suite 500, Silver Spring, MD 20910 under contract 68-W6-0014, work assignments 73 and

94, with the U.S. Environmental Protection Agency. Mention of trade names or commercial products

does not constitute endorsement or recommendation for use. For more information about this project

contact: Dawn Carroll, U.S. Environmental Protection Agency (5102G), Technology Innovation Office,

401 M Street, SW, Washington, DC 20460, 703-603-1234, e-mail: carroll.dawn@epa.gov.
i

FOREWORD

Identifying and accessing pertinent information resources that will help site cleanup managers evaluate

innovative technologies is key to the broader use of these technologies. This Guide is intended to

increase awareness about technical information and specialized resources related to phytoremediation

technologies.

Specifically, this document identifies a cross section of information intended to aid users in remedial

decision-making, including abstracts of field demonstrations, research documents, and information to

assist in the ordering of publications. In addition, the look-up format of this document allows the user

to quickly scan available resources and access more detailed abstracts.

Please let us know about additional information that could make this Guide (and others in the series)

more useful to you. This and the other reports listed below are available to the public from the

Technology Innovation Office Home Page: http://www.epa.gov/tio.

Bioremediation Resource Guide

Groundwater Treatment Technology Resource Guide

Physical/Chemical Treatment Technology Resource Guide

Soil Vapor Extraction (SVE) Enhancement Technology Resource Guide

Soil Vapor Extraction Treatment Technology Resource Guide
ii

TABLE OF CONTENTS

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

HOW TO USE THIS GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

HOW TO ORDER DOCUMENTS LISTED IN THIS GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi

TECHNOLOGY SUMMARY AND MATRIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

ABSTRACTS OF PHYTOREMEDIATION RESOURCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Publications Containing Multiple Papers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Organic Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Overviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Field Studies and Demonstrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Publications Containing Multiple Papers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Inorganic Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Overviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Field Studies and Demonstrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Publications Containing Multiple Papers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Internet Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
iii

INTRODUCTION

EPA is committed to identifying the most effective and efficient means of addressing the thousands of

hazardous waste sites in the United States. Therefore, the Office of Solid Waste and Emergency

Response’s (OSWER’s) Technology Innovation Office (TIO) is working in conjunction with the EPA

Regions and research centers and with industry to identify and encourage the further development and

implementation of innovative treatment technologies.

One way to encourage the use of these technologies is to ensure that decision-makers are aware of the

most current information on technologies, policies, and other sources of assistance. This Guide was

prepared to help identify documents that can directly assist Federal and State site managers,

contractors, and others responsible for the evaluation of technologies. Specifically, this Guide is

designed to help those responsible for the remediation of RCRA, UST, and CERCLA sites that may

employ phytoremediation technologies.

This Guide provides abstracts of over 100 phytoremediation overviews, field studies and

demonstrations, research articles, and Internet resources. It also provides a brief summary of

phytoremediation. Finally, a matrix is also provided to allow easy screening of the abstracted

references.

To develop this Guide, a literature search using relevant terms was conducted on a variety of

commercial and Federal databases including:

& National Technical Information Service (NTIS)

& Energy Science and Technology

& Enviroline

& Water Resources Abstracts

& Pollution Abstracts. 

In addition, Internet resources yielded numerous citations. These Internet resources include: 

& U.S. Environmental Protection Agency 

http://www.epa.gov

& U.S. Army Corps of Engineers Phytoremediation Research

http://www.wes.army.mil/EL/phyto

& U.S. Army Environmental Center

http://aec-www.apgea.army.mil:8080

& Air Force Center for Environmental Excellence

http://www.afcee.brooks.af.mil

& U.S. Department of Energy

http://www.doe.gov

& U.S. Department of Agriculture

http://www.usda.gov

& The Hazardous Waste Clean-Up Information Home Page

http://clu-in.org

& The Ground Water Remediation Technologies Analysis Center

http://www.gwrtac.org
iv

& The Remediation Technologies Development Forum

http://www.rtdf.org

& The Great Plains/Rocky Mountain Hazardous Substance Research Center

http://www.engg.ksu.edu/HSRC

& The Phytoremediation Electronic Newsgroup Network

http://www.dsa.unipr.it/phytonet

& The Interstate Technology and Regulatory Cooperation Working Group

http://www.sso.org/ecos/itrc

& Battelle

http://www.battelle.org

The selected references are not an exhaustive list of all available literature, but rather a representative

sample of available print and Internet resources. For a more extensive list of phytoremediation

resources, visit the Remediation Technologies Development Forum, Phytoremediation of Organics

Action Team’s Home Page at http://www.rtdf.org/public/phyto. The Remediation Technologies

Development Forum is a public-private partnership operated by the U.S. Environmental Protection

Agency. The Phytoremediation of Organics Action Team includes representatives from industry and

government who share an interest in further developing and evaluating the use of plants and trees to

remediate contaminated soil and water. The Action Team has compiled a bibliography containing over

1,400 citations of peer-reviewed journal articles, presentations and posters from conferences, book

chapters, and articles from newspapers and magazines. The bibliography may be viewed or searched

online.

Due to the inherent lag time between document publication and subsequent listing in electronic

databases, there may be more recent references available than those included in the Guide. Most of the

references in the Guide are of documents published between 1994 and 1998. The documents selected

are available from suppliers such as EPA’s National Service Center for Environmental Publications, the

National Technical Information Service, document delivery services, and a variety of libraries.

Descriptions of specific technologies and methodologies in this Guide does not represent an

endorsement by EPA. 
v

HOW TO USE THIS GUIDE

When using this Guide to identify resource information on phytoremediation technologies, you may

wish to take the following steps:

1. Turn to the Phytoremediation Resource Matrix located on pages ix through xxii of this Guide.

This matrix lists all abstracted resources alphabetically by document type, identifies the type of

information provided by each document, and provides a document ordering number when

available. Documents in the matrix are divided into the following topical categories: general

information, organic contaminants, inorganic contaminants, and Internet resources.

2. Select the documents that appear to fit your needs based on the information in the matrix.

3. Check the page number provided in the matrix. This refers to the page number of the document

abstract in the Guide.

4. Review the abstract that corresponds to the document in which you are interested to confirm that

the document will fit your needs.

5. If the document appears to be appropriate, note the document number highlighted under the

abstract. For example:

EPA Document Number: EPA 542-R-97-004

[Note: Some documents do not have ordering numbers. These documents can be obtained through

local, technical, or university libraries.]

6. Turn to the section entitled “How to Order Documents Listed in this Guide” on page vi of this

Guide and order your document using the directions provided.
vi

HOW TO ORDER DOCUMENTS LISTED IN THIS GUIDE

Documents listed in this Guide are available through a variety of sources. When ordering documents

listed in the Abstracts section of this Guide, use the number listed in the bar below the document title,

or refer to the source indicated as part of the citation. If using the Phytoremediation Resource

Matrix, use the page number listed with the document title to refer to the complete citation and

abstract. EPA 542 documents may be obtained through the National Service Center for Environmental

Publications (NSCEP), and EPA 530 documents may be obtained from the RCRA Information Center

(RIC). These document repositories provide in-stock documents free of charge, but document supplies

may be limited. Documents obtained through the National Technical Information Service (NTIS) are

available for a fee; therefore, prior to purchasing a document through NTIS, you may wish to review a

copy at a technical or university library, or a public library that houses government documents.

Document Type

Publication numbers with the following prefixes: 

AD

DE

PB

NTIS provides documents for a fee.

Document Source

National Technical Information Service (NTIS)

5285 Port Royal Road

Springfield, VA 22161

Tel: 1-800-553-NTIS

Fax: (703) 605-6900

Internet: http://www.ntis.gov/

Publications numbers beginning with:

EPA 542

National Service Center for Environmental

Publications (NSCEP)

P.O. Box 42419

Cincinnati, OH 45242-2419

Tel: 1-800-490-9198

Fax: (513) 489-8695

Internet: http://www.epa.gov/ncepihom/

A document title or number is needed to place an order with NSCEP.

Some out-of-stock documents may be purchased from NTIS.

Publications numbers beginning with:

EPA 530

RCRA Information Center (RIC)

401 M St., SW Mailcode: 5305

Washington, DC 20460

Tel: (703) 603-9230

Fax: (703) 603-9234

Internet: http://www.epa.gov/epaoswer/general/

ricorder.htm
vii

TECHNOLOGY SUMMARY

Phytoremediation is the direct use of living plants for in situ remediation of contaminated soil, sludges,

sediments, and ground water through contaminant removal, degradation, or containment. Growing and,

in some cases, harvesting plants on a contaminated site as a remediation method is an aesthetically

pleasing, solar-energy driven, passive technique that can be used to clean up sites with shallow, low to

moderate levels of contamination. This technique can be used along with or, in some cases, in place of

mechanical cleanup methods. Phytoremediation can be used to clean up metals, pesticides, solvents,

explosives, crude oil, polycyclic aromatic hydrocarbons, and landfill leachates.

Phytoremediation has been studied extensively in research and small-scale demonstrations, but fullscale applications are currently limited in number. Further development and research of the

mechanisms described below likely will lead to wider acceptance and use of phytoremediation.

Phytoremediation is a general term for several ways in which plants are used to remediate sites by

removing pollutants from soil and water. Plants can degrade organic pollutants or contain and stabilize

metal contaminants by acting as filters or traps. Some of the methods that are being tested are described

below. 

Phytoextraction Phytoextraction, also called phytoaccumulation, refers to the uptake and

translocation of metal contaminants in the soil by plant roots into the

aboveground portions of the plants. Certain plants called hyperaccumulators

absorb unusually large amounts of metals in comparison to other plants. One or

a combination of these plants is selected and planted at a site based on the type

of metals present and other site conditions. After the plants have been allowed

to grow for several weeks or months, they are harvested and either incinerated

or composted to recycle the metals. This procedure may be repeated as

necessary to bring soil contaminant levels down to allowable limits. If plants

are incinerated, the ash must be disposed of in a hazardous waste landfill, but

the volume of ash will be less than 10% of the volume that would be created if

the contaminated soil itself were dug up for treatment. 

Rhizofiltration Rhizofiltration is the adsorption or precipitation onto plant roots or absorption

into the roots of contaminants that are in solution surrounding the root zone.

The plants to be used for cleanup are raised in greenhouses with their roots in

water rather than in soil. To acclimate the plants once a large root system has

been developed, contaminated water is collected from a waste site and brought

to the plants where it is substituted for their water source. The plants are then

planted in the contaminated area where the roots take up the water and the

contaminants along with it. As the roots become saturated with contaminants,

they are harvested and either incinerated or composted to recycle the

contaminants.

Phytostabilization Phytostabilization is the use of certain plant species to immobilize contaminants

in the soil and ground water through absorption and accumulation by roots,
viii

adsorption onto roots, or precipitation within the root zone. This process

reduces the mobility of the contaminant and prevents migration to the ground

water or air, and it reduces bioavailability for entry into the food chain. This

technique can be used to reestablish a vegetative cover at sites where natural

vegetation is lacking due to high metal concentrations in surface soils or

physical disturbances to surficial materials. Metal-tolerant species can be used

to restore vegetation to the sites, thereby decreasing the potential migration of

contamination through wind erosion, transport of exposed surface soils, and

leaching of soil contamination to ground water.

Phytodegradation Phytodegradation, also called phytotransformation, is the breakdown of

contaminants taken up by plants through metabolic processes within the plant,

or the breakdown of contaminants external to the plant through the effect of

compounds (such as enzymes) produced by the plants. Pollutants are degraded,

incorporated into the plant tissues, and used as nutrients.

Rhizodegradation Rhizodegradation, also called enhanced rhizosphere biodegradation,

phytostimulation, or plant-assisted bioremediation/degradation, is the

breakdown of contaminants in the soil through microbial activity that is

enhanced by the presence of the rhizosphere and is a much slower process than

phytodegradation. Microorganisms (yeast, fungi, or bacteria) consume and

digest organic substances for nutrition and energy. Certain microorganisms can

digest organic substances such as fuels or solvents that are hazardous to

humans and break them down into harmless products through biodegradation.

Natural substances released by the plant roots—sugars, alcohols, and

acids—contain organic carbon that provides food for soil microorganisms, and

the additional nutrients enhance their activity. Biodegradation is also aided by

the way plants loosen the soil and transport water to the area.

Phytovolatilization Phytovolatilization is the uptake and transpiration of a contaminant by a plant,

with release of the contaminant or a modified form of the contaminant to the

atmosphere from the plant. Phytovolatilization occurs as growing trees and

other plants take up water and the organic contaminants. Some of these

contaminants can pass through the plants to the leaves and volatilize into the

atmosphere at comparatively low concentrations.
ix

PHYTOREMEDIATION RESOURCE MATRIX

The Phytoremediation Resource Matrix displays summary information on references listed in the Abstracts section o

exception of publications containing multiple papers. Both the Matrix and Abstracts sections are organized using the sa

categories. Internet Resources are listed in a separate matrix following printed references. The first column of the Matridocument title, ordering number (when applicable), and page number of the full abstract in the Abstracts section. The s

(Technology Type) lists the technologies that the article addresses. Definitions for these technologies can be found in the on page vii. Column three denotes the media treated, and column four denotes the contaminants treated.

Document TitleDocument Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

GENERAL INFORMATIONThe 1998 United States Market for Phytoremediation [1] Unspecified qq q The Advancement of Phytoremediation as an InnovativeEnvironmental Technology for Stabilization, Remediation, orRestoration of Contaminated Sites in Canada: A Discussion Paper[2]

Unspecified

qq q 

Bioremediation and Phytoremediation Glossary [2] Unspecified qq q A Citizen’s Guide to Phytoremediation [2]EPA 542-F-98-011

Unspecified qq q q 

Compost-Enhanced Phytoremediation of Contaminated Soil [2]EPA 530-R-98-008

Unspecified qq 

Introduction to Phytoremediation [2] Unspecified qq q 
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

x

Legal and Social Concerns to the Development of BioremediationTechnologies [3]

DE96015254

Unspecified

qq q 

Phytoremediation [3]EPA 625-K-96-001

Unspecified qq q 

Phytoremediation [3] Unspecified qq q Phytoremediation: A Clean Transition from Laboratory toMarketplace? [3]

Phytoremediation: A New Technology Gets Ready to Bloom [3] Unspecified qq q 

Phytoremediation Bibliography [4] Unspecified qq q Phytoremediation Field Demonstrations in the U.S. EPA SITEProgram [4]

Phytoextraction qq q 

Phytoremediation: It Grows on You [4] Unspecified qq q Phytoremediation on the Brink of Commercialization [4] Unspecified qq q Phytoremediation: Technology Overview Report [5] Unspecified qq q Phytoremediation: Using Green Plants to Clean Up ContaminatedSoil, Groundwater, and Wastewater [5]

Phytostabilization qq q 

Remediation Technologies Screening Matrix and Reference Guide[5]

Unspecified qq q 
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xi

Stemming the Toxic Tide [5] Phytoextraction qq q Technology Evaluation Report: Phytoremediation [6] Unspecified qq q Using Phytoremediation to Clean Up Contamination at MilitaryInstallations [6]DE97007971

Unspecified

qq q 
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xii

ORGANIC CONTAMINANTSOverviewsMechanisms of Phytoremediation: Biochemical and EcologicalInteractions Between Plants and Bacteria [7]

Rhizodegradation q q

Phytoremediation of TCE in Groundwater Using Populus [8] Phytodegradation

Phytovolatilization q q

Field Studies and DemonstrationsDemonstration Plan for Phytoremediation of Explosive-Contaminated Groundwater in Constructed Wetlands at Milan ArmyAmmunition Plant, Milan, Tennessee. Volumes 1 and 2. FinalReport [8]ADA311121/8/XAB, ADA311122/6/XAB

Phytodegradation

q 

Evaluation of Various Organic Fertilizer Substrates and HydraulicRetention Times for Enhancing Anaerobic Degradation ofExplosives-Contaminated Groundwater While Using ConstructedWetlands at the Milan Army Ammunition Plant, Milan, Tennessee[8]ADA349293

Phytodegradation

q 

Field Scale Evaluation of Grass-Enhanced Bioremediation of PAHContaminated Soils [8]

Rhizodegradation q q

Friendly Forests [9] Phytostabilization

PhytodegradationRhizodegradation

qq q
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xiii

Groundwater Phytoremediation Test Facility, University ofWashington [9]

Rhizofiltration q q

Phreatophyte Influence on Reductive Dechlorination in a ShallowAquifer Containing TCE [9]

Rhizodegradation q q

Phytoremediation of Dissolved-Phase Trichloroethylene UsingMature Vegetation [10]

Phytovolatilization q q

Phytoremediation of Groundwater at Avesta Sheffield Pipe [10] Unspecified qq qPhytoremediation of Organic and Nutrient Contaminants [10] Phytodegradation qq q qPilot-Scale Use of Trees to Address VOC Contamination [10] Phytodegradation q qScreening of Aquatic and Wetland Plant Species for Phytoremediation of Explosives-Contaminated Groundwater from the Iowa ArmyAmmunition Plant. Final Report [10]ADA322455/7/XAB

Phytodegradation

q 

Screening Submersed Plant Species for Phytoremediation ofExplosives-Contaminated Groundwater from the Milan ArmyAmmunition Plant, Milan, Tennessee. Final Report [11]

Phytodegradation

q 

ResearchAdsorption of Naphthalene onto Plant Roots [11] Phytostabilization q qAromatic Nitroreduction of Acifluorfen in Soils Rhizospheres andPure Cultures of Rhizobacteria [11]

Rhizodegradation q q
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xiv

Bacterial Inoculants of Forage Grasses that Enhance Degradation of2-Chlorobenzoic Acid in Soil [11]

Rhizodegradation q q

Bioremediation Bacteria to Protect Plants in PentachlorophenolContaminated Soil [12] Rhizodegradation q qDecreased Transpiration in Popular Trees Exposed to 2,4,6-Trinitrotoluene [12]

Phytovolatilization q 

Degradation of Polychlorinated Biphenyls by Hairy Root Culture ofSolanum nigrum [12]

Phytodegradation q q

Detoxification of Phenol by the Aquatic Angiosperm, Lemna gibba[12]

Phytodegradation q q

Effect of Hybrid Poplar Trees on Microbial Populations Importantto Hazardous Waste Bioremediation [13]

Rhizodegradation q qq

Effects of Ryegrass on Biodegradation of Hydrocarbons in Soil [13] Rhizodegradation q qA Field Facility for Phytoremediation Research [13] Phytodegradation qq Greenhouse Evaluation of Agronomic and Crude OilPhytoremediation Potential Among Alfalfa Genotypes [13] Phytodegradation q qThe Influence of Planting and Soil Characteristics onMineralization of 2,4,5-T in Rhizosphere Soil [14]

Rhizodegradation q q

Mineralization of 2,4-Dichlorophenol by Ectomycorrhizal Fungi inAxenic Culture and in Symbiosis with Pine [14]

Rhizodegradation q q
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xv

Phytoremediation Experimentation with the Herbicide Bentazon[14]

Phytodegradation q q

Phytoremediation: Modeling Removal of TNT and Its BreakdownProducts [14]

Phytodegradation q 

Phytoremediation of 1,4-dioxane by Hybrid Poplars [14] Phytovolatilization

Rhizodegradation q q

Phytoremediation of Hazardous Wastes [15] Phytodegradation qq Phytoremediation of Organic Contaminants: A Review ofPhytoremediation Research at the University of Washington [15]

Phytodegradation qq q

Phytoremediation of Pesticide-Contaminated Soils [15] Rhizodegradation q qPhytoremediation of Trichloroethylene with Hybrid Poplars [16] Rhizofiltration q qPhytoremediation, Plant Uptake of Atrazine and Role of RootExudates [16]

Rhizodegradation q q

Phytotreatment of TNT-Contaminated Groundwater [16] Phytodegradation q Plant Cell Biodegradation of a Xenobiotic Nitrate Ester,Nitroglycerin I [16]

Phytodegradation q 

Plant-Enhanced Remediation of Petroleum Contaminated Soil [17] Phytodegradation

Rhizodegradation q q

Plant-Enhanced Subsurface Bioremediation of NonvolatileHydrocarbons [17]

Rhizodegradation q q
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xvi

Potential of Phytoremediation as a Means for Habitat Restorationand Cleanup of Petroleum Contaminated Wetlands [17]

Phytodegradation q q

Rhizosphere Microbial Populations in Contaminated Soils [17] Rhizodegradation q qTransformation of TNT by Aquatic Plants and Plant TissueCultures [18]

Phytodegradation q 

Uptake and Fate of Organohalogens from ContaminatedGroundwater in Wood Plants [18]

PhytodegradationPhytovolatilization q q
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xvii

INORGANIC CONTAMINANTSOverviewsEmerging Technologies for the Remediation of Metals in Soils:Phytoremediation [18]

Unspecified q 

Literature Review: Phytoaccumulation of Chromium, Uranium,Plutonium in Plant Systems [19]

Phytoextraction q 

Remediation of Metal-Contaminated Sites Using Plants [19] Phytoextraction q Restoration of Mined Lands—Using Natural Processes [19] Unspecified q Status of In Situ Phytoremediation Technology [19]EPA 542-R-97-004

PhytoextractionPhytostabilizationRhizofiltration

q 

Field Studies and DemonstrationsPhytoaccumulation of Trace Elements by Wetlands Plants: I.Duckweed [20]

Phytoextraction q 

Relationship Between Sulfur Speciation in Soils and PlantAvailability [20]

Phytoextraction q 

Removal of Uranium from Water Using Terrestrial Plants [20] Rhizofiltration q ResearchDifferences in Root Uptake of Radiocesium by 30 Plant Taxa [20] Phytoextraction q 
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xviii

Enhanced Accumulation of Pb in Indian Mustard by Soil-AppliedChelating Agents [21]

Phytoextraction q 

Evaluation of Tamarisk and Eucalyptus Transpiration for theApplication of Phytoremediation [21]

Phytoextraction q 

Feasibility of Using Plants to Assist in the Remediation of HeavyMetal Contamination at J-Field, Aberdeen Proving Ground,Maryland. Final Report [21]

Phytoextraction

q 

Lead-Contaminated Sediments Prove Susceptible toPhytoremediation [21]

Phytoextraction q 

Lead Uptake and Effects on Seed Germination and Plant Growth ina Pb Hyperaccumulator Brassica pekinensis Rupr. [22]

Phytoextraction q 

Metal Accumulation by Aquacultured Seedlings of Indian Mustard[22]

Phytoextraction q 

Phytoextraction of Cadmium and Zinc from a Contaminated Soil[22]

Phytoextraction q 

Phytoextraction of Zinc by Oat (Avena sativa), Barley (Hordeum

vulgare), and Indian Mustard (Brassica juncea) [23]

Phytoextraction q 

Phytoextraction: the Use of Plants to Remove Heavy Metals fromSoils [23]

Phytoextraction q 

Phytofiltration of Hazardous Cadmium, Chromium, Lead and ZincIons by Biomass of Medicago sativa (Alfalfa) [23]

Rhizofiltration q 
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xix

Phytoremediation of a Radiocesium-Contaminated Soil: Evaluationof Cesium137 Bioaccumulation in the Shoots of Three Plant Species

[23]

Phytoextraction

q 

Phytoremediation of Lead-Contaminated Soils: Role of SyntheticChelates in Lead Phytoextraction [24]

Phytoextraction q 

Phytoremediation of Selenium Laden Soils: A New Technology[24]

Phytoextraction q 

Phytoremediation of Uranium-Contaminated Soils: Role of OrganicAcids in Triggering Uranium Hyperaccumulation in Plants [24]

Phytoextraction q 

Potential for Phytoextraction of 137Cs from a Contaminated Soil [25] Phytoextraction q Potential Remediation of 137Cs and 90Sr Contaminated Soil by

Accumulation in Alamo Switchgrass [25]

Phytoextraction q 

Rhizofiltration: the Use of Plants to Remove Heavy Metals fromAqueous Streams [25]

Rhizofiltration q 

The Role of EDTA in Pb Transport and Accumulation by IndianMustard [25]

Phytoextraction q 

A Search for Lead Hyperaccumulating Plants in the Laboratory [26] Rhizofiltration

Phytoextraction q 

Selenium Accumulation by Brassica Napus Grown in Se-laden Soilfrom Different Depths of Kersterson Reservoir [26]

Phytoextraction q 
Document Title

Document Ordering Number[Abstract Page Number in Guide]

Technology

Type

Media Conta

Soil

Ground Water

Organics

Pesticides/

Herbicides

xx

Test Plan for the Phytoremediation Studies of Lead-ContaminatedSoil from the Sunflower Army Ammunition Plant, Desoto, Kansas.Vol. 1 and Vol. 2 [26]ADA342667, ADA342668

Phytoextraction

q 

Toxicity of Zinc and Copper to Brassica Species: Implications forPhytoremediation [26]

PhytoextractionPhytostabilization q 

Toxic Mercury Reduction and Remediation Using TransgenicPlants with a Modified Bacterial Gene [27]

PhytoextractionPhytostabilization 

Zinc and Cadmium Accumulation in the Hyperaccumulator ThlaspiCaerulescens in Response to Limestone and Compost Applicationsto a Heavy Metal Contaminated Site in Palmerton, Pennsylvania[27]

Phytoextraction

q 
xxi

Web Site TitleURL[Abstract Page Number in Guide]

Media 

Soil

Ground Water

INTERNET RESOURCESAdvanced Applied Technology Demonstration Facility (AATDF)http://www.ruf.rice.edu/~aatdf [27] q Air Force Center for Environmental Excellence (AFCEE)http://www.afcee.brooks.af.mil [27] q Alternative Treatment Technology Information Center (ATTIC)http://www.epa.gov/attic [28] qq CLU-IN: Hazardous Waste Clean-Up Informationhttp://clu-in.org [28] qq Environmental Security Technology Certification Program (ESTCP)http://www.estcp.org [28] qq Federal Remediation Technologies Roundtablehttp://www.frtr.gov [28] qq GNET: The Global Network of Environment and Technologyhttp://www.gnet.org [28]Great Plains/Rocky Mountain Hazardous Substance Research Centerhttp://www.ecc.ksu.edu/HSRC [28] qq Ground Water Remediation Technologies Analysis Center (GWRTAC)http://www.gwrtac.org [29] qq 
Web Site Title

URL[Abstract Page Number in Guide]

Media 

Soil

Ground Water

xxii

Innovative Treatment Remediation Demonstration (ITRD) http://www.em.doe.gov/itrd [29] qInterstate Technology and Regulatory Cooperation Working Group (ITRC)http://www.sso.org/ecos/itrc [29] q PHYTONET - Phytoremediation Electronic Newsgroup Networkhttp://www.dsa.unipr.it/phytonet [29] qq Remediation Technologies Development Forum (RTDF) Phytoremediation of Organics Action Teamhttp://www.rtdf.org/public/phyto [29]

qq 

Strategic Environmental Research and Development Program (SERDP)http://www.serdp.gov [30] q U.S. Army Corps of Engineers Phytoremediation Researchhttp://www.wes.army.mil/EL/phyto [30] q U.S. Army Environmental Center (USAEC)http://aec-www.apgea.army.mil:8080 [30] qq U.S. Department of Agriculture (USDA)http://www.usda.gov [29] qq 
1

ABSTRACTS OF PHYTOREMEDIATION RESOURCES

The resources below describe the contents of pertinent phytoremediation documents and Internet resources. The

references and resources are organized alphabetically within each of the following categories:

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Publications Containing Multiple Papers ................................................ 6

Organic Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Overviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Field Studies and Demonstrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Publications Containing Multiple Papers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Inorganic Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Overviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Field Studies and Demonstrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Publications Containing Multiple Papers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Internet Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

To quickly identify documents and resources pertinent to your interest area, see the Phytoremediation Resource

Matrix on pages ix-xxii of this Guide. The documents and resources in the matrix are organized alphabetically

within the categories identified above. Listings in the matrix can be cross-referenced with the abstracts by referring

to the page number provided in the matrix. In an effort to limit the number of resources listed here, documents

published prior to 1990 are not included. These abstracts were obtained from several databases, including the

National Technical Information Service, Energy Science and Technology, Enviroline, Water Resources Abstracts,

and Pollution Abstracts as well as several Internet resources.

General Information

The 1998 United States Market for

Phytoremediation

Glass, D.J.

D. Glass Associates, Inc., Needham, MA 140 pp April

1998

Phytoremediation, the use of plants, trees, and other

vegetation to remove, sequester, or degrade

environmental contaminants, has attracted a great deal

of interest in recent years. Drawing on the abilities of

plants to accumulate metals and other substances or

take up and transpire large amounts of water,

phytoremediation is an effective, low-cost treatment

technology that is beginning to gain the attention of

private and industrial site owners, regulators, and the

environmental engineering community. This report

includes a technology summary, commercial company

profiles, research group profiles, an industry analysis

and market forecast, summaries of several completed

and ongoing phytoremediation projects, a review of the

advantages and disadvantages of the technology, and a

glossary.
2

The Advancement of Phytoremediation as an

Innovative Environmental Technology for

Stabilization, Remediation, or Restoration of

Contaminated Sites in Canada: A Discussion Paper

McIntyre, T. and Lewis, G.M.

Journal of Soil Contamination v 6:3 p 227(15) May

1997

Environment Canada's Environmental Technologies

Advancement Division is exploring the potential of

phytoremediation as a major, long-term technology

approach. The benefits and limitations of

phytoremediation and its potential for bioremediation

of soil and ground water in Canada are discussed.

Research issues that will need to be addressed to further

phytoremediation technology are examined. Other

regulatory, legal, commercial, and social issues are

considered briefly.

Bioremediation and Phytoremediation Glossary 

Bentjen, S.

Available at

http://members.tripod.com/~bioremediation

This glossary lists terms related to bioremediation

(microbial degradation) and phytoremediation

(remediation using green plants) of environmental

pollutants. Links to other environmental glossaries

appear at the bottom of the page. 

A Citizen’s Guide to Phytoremediation

U.S. EPA, Office of Solid Waste and Emergency

Response 

6 pp August 1998

Available at http://clu-in.org

EPA Document Number: EPA 542-F-98-011 

EPA’s Technology Innovation Office has published a

Technology Fact Sheet that describes what

phytoremediation is, how it works, what its limitations

are, and where to find additional information.

Compost-Enhanced Phytoremediation of

Contaminated Soil

U.S. EPA, Office of Solid Waste and Emergency

Response

Published in Analysis of Composting as an

Environmental Remediation Technology p 87(12) 

April 1998

EPA Document Number: EPA 530-R-98-008

Phytoremediation is a developing technology in which

higher plants and microorganisms associated with plant

roots are the active agents for uptake and/or

degradation of toxic inorganic and organic compounds

in soil and water. Plants can also provide containment

by reducing the erosional transport of contaminated

soil. Numerous reports indicate that plants can take up

and degrade toxic organic compounds in soil, while

other work indicates microorganisms in the rhizosphere

are very competent degraders of soil-borne organics.

This process might be suitable for soil remediation

and/or inexpensive confinement of shallow

contaminated water. Phytoremediation of

metal-contaminated soil relies on the ability of plants to

accumulate metals at concentrations substantially above

those found in the soil in which they grow.

Phytoremediation has very large economic advantages

over mechanically intensive technologies.

Introduction to Phytoremediation

U.S. EPA, National Risk Management Research

Laboratory

To be issued in 1999

To be available at http://www.rtdf.org

This handbook is the work of the EPA

Phytoremediation Handbook Team in conjunction with

the Remediation Technologies Development Forum

(RTDF) Phytoremediation Action Team. It was

developed to provide a tool for site regulators, owners,

neighbors, and managers to evaluate the applicability of

phytoremediation to a site. Phytoremediation projects

have been proposed or applied to ecosystem restoration

and soil, surface water, ground water, and sediment

remediation. This document identifies, defines, and

provides a framework to evaluate these

phytoremediation applications, although it is not a

design guide. It also presents case studies illustrating

field applications of phytoremediation.
Abstracts of Phytoremediation Resources General Information

3

Legal and Social Concerns to the Development of

Bioremediation Technologies 

Bilyard, G.R.; et al.

150 pp Sep 1996

NTIS Document Number: DE96015254 

The social and legal framework within which

bioremediation technologies must be researched,

developed, and deployed in the U.S. are discussed in

this report. Discussions focus on policies, laws and

regulations, intellectual property, technology transfer,

and stakeholder concerns. These discussions are

intended to help program managers, scientists and

engineers understand the social and legal framework

within which they work, and be cognizant of relevant

issues that must be navigated during bioremediation

technology research, development, and deployment

activities. While this report focuses on the legal and

social environment within which the DOE operates, the

laws, regulations and social processes could apply to

other sites nationwide. This report identifies specific

issues related to bioremediation technologies, including

those involving the use of plants; native, naturally

occurring microbes; non-native, naturally occurring

microbes; genetically engineered organisms; and

microbial products (e.g., enzymes, surfactants,

chelating compounds).

Phytoremediation

Rock, S. and Pope, D.

Published in Seminars: Bioremediation of Hazardous

Waste Sites: Practical Approaches to Implementation p

8.1(9) 1996

EPA Document Number: EPA 625-K-96-001

Chapter eight of the seminar publication contains a

description of the different aspects of phytoremediation,

applications and examples, a bibliography, and

illustrations from the poster session.

Phytoremediation 

Salt, D.E.; Smith, R.D.; and Raskin, I.

Annual Review of Plant Physiology and Plant

Molecular Biology v 49 p 643(26) 1998

Phytoremediation, a cost-effective plant-based approach

to remediation, takes advantage of the ability of plants

to concentrate elements and compounds from the

environment and to metabolize various molecules in

their tissues. Several field trials have confirmed the

feasibility of using plants for environmental cleanup.

This review concentrates on the most developed subsets

of phytoremediation technology and on the biological

mechanisms that make phytoremediation work.

Phytoremediation: A Clean Transition from

Laboratory to Marketplace?

Boyajian, G.E. and Carreira, L.H.

Natural Biotechnology v 15:2 p 127(2) 1997

In recent years, the potential of plants for

environmental cleanup—phytoremediation—has been

recognized, and U.S. government agencies and private

corporations have responded by increasingly supporting

research in this area. The report in this issue by Goel et

al. both advances our basic knowledge of plant

biochemistry and demonstrates that plants are indeed

capable of tackling such exotic xenobiotic contaminants

as nitroglycerin.

Phytoremediation: A New Technology Gets Ready to

Bloom

Bishop, J.

Environmental Solutions v 10:4 p 29(6) May-June 1997

Phytoremediation is the use of selected crop plants or

trees to extract or promote degradation of toxic

substances in soils, ground water, surface water,

wastewater and sediments. It may be possible in some

cases to harvest such contaminants as heavy metals that

have been taken up by plants and recover them for

recycling. In other variations, plants stimulate the

growth of naturally occurring microbial populations,

which then degrade organic contaminants, such as

petroleum hydrocarbons, in soils. At appropriate sites, 

the cost of applying phytoremediation techniques may

range from half to less than 20% of the cost of using

physical, chemical, or thermal techniques.
Abstracts of Phytoremediation Resources General Information

4

Phytoremediation Bibliography 

Available at http://www.rtdf.org

This searchable bibliography of over 1,400 citations is

the work of the EPA Phytoremediation Handbook Team

in conjunction with the Remediation Technologies

Development Forum (RTDF) Phytoremediation Action

Team. The bibliography is updated frequently.

Phytoremediation Field Demonstrations in the U.S.

EPA SITE Program

Rock, S. and Beckman, S. 

In Situ and On-Site Bioremediation: Volume 3

Battelle Press, Columbus, OH p 323 [abstract only]

1998

U.S. EPA National Risk Management Research

Laboratory’s SITE program is evaluating

phytoremediation’s efficacy and cost at field scale

demonstrations on sites in Oregon, Utah, Texas, and

Ohio. The Superfund Innovative Technology

Evaluation (SITE) Program is a part of EPA’s research

into alternative cleanup methods for hazardous waste

sites. The EPA teamed with USAF, USGS, Ohio EPA,

Chevron USA, Phytotech, Inc., and Phytokinetics, Inc.

to accomplish these demonstrations. At a wood treater

in Portland, Oregon, shallow soil contaminated with

PCP and PAHs is being treated with a perennial

ryegrass. In Ogden, Utah, a combination of poplar

trees, juniper trees, alfalfa, and fescue has been planted

to remediate a petroleum spill which has polluted both

the soil and the ground water. On an Air Force facility

near Fort Worth, Texas, cottonwood trees are being

used to intercept a part of a large TCE ground water

plume. In Ohio, the shallow soil of a former metal

plating facility is the site for a demonstration of

phytoextraction of lead, cadmium, and hexavalent

chromium using Indian mustard. Each demonstration

includes monitoring the soil, ground water, and plant

material. The sites were planted in 1996, and will be

monitored until at least 1999. [Abstract only.

Additional information is available at http://clu-in.org

under the SITE Demonstration Program page.]

Phytoremediation: It Grows on You

Boyajian, G. E. and Devedjian, D.L.

Soil & Groundwater Cleanup p 22(5) February-March

1997

Phytoremediation is a small but growing subset of in

situ remediation technologies for contaminated soil.

Plants can be effective remediators by reaching

contaminants through their root systems, their ability to

accumulate metals and degrade organic compounds,

and their reduced cost compared with other approaches.

However, only those plants having the appropriate

biochemical pathways are effective for soil cleanup.

Identification of appropriate plants for remediation of

organic compounds and heavy metals is discussed.

Phytoremediation on the Brink of

Commercialization

Watanabe, M.E.

Environmental Science & Technology v 31:4 p 182A(4)

1997

Academic, government, and corporate researchers have

a body of data on the ability of certain plants to either

remove pollutants from the environment or render them

harmless, and they are looking for ways to improve

these traits through plant breeding and molecular

techniques. In the past three years, at least three new

companies have formed to use plants to clean sites

contaminated with heavy metals or organics.

Phytoremediation is a natural process carried out by

plants, especially those that are able to survive in

contaminated soil and water. Hyperaccumulators are

plants that can absorb high levels of contaminants with

their roots and concentrate them either there or in

shoots and leaves. Researchers have found

hyperaccumulator species by collecting plants in areas

where soil contains greater than usual amounts of

metals or other potentially toxic compounds because of

geological factors or pollution. Among the plants that

have been collected and used in field trials are species

from the genus Thlaspi, or Alpine pennycress, which

accumulate zinc, cadmium, or lead, and Alyssum

species, which accumulate nickel. Both genera belong

to the mustard family Brassicaceae. Plants from other

families also have been shown to remove cobalt,

copper, chromium, manganese, or selenium from

contaminated soils.
Abstracts of Phytoremediation Resources General Information

5

Phytoremediation: Technology Overview Report

Miller, R.

Groundwater Remediation Technologies Analysis

Center, Pittsburgh, PA 26 pp 1996

Available at http://www.gwrtac.org

Phytoremediation uses plants to cleanup contaminated

soil and ground water, taking advantage of plants'

natural abilities to take up, accumulate, and/or degrade

constituents of their soil and water environments.

Research results report it to be applicable to a broad

range of contaminants including numerous metals,

radionuclides, and various organic compounds (such as

chlorinated solvents, BTEX, PCBs, PAHs,

pesticides/insecticides, explosives, nutrients, and

surfactants). According to information reviewed,

general site conditions best suited for use of

phytoremediation include large areas of low to

moderate surface soil (0 to 3 feet) contamination or

large volumes of water with low-level contamination

subject to low (stringent) treatment standards. Major

advantages reported for phytoremediation as compared

to traditional remediation technologies include the

possibility of generating less secondary wastes, minimal

associated environmental disturbance, and the ability to

leave soils in place and in a usable condition following

treatment. Cited disadvantages include the long lengths

of time required (usually several growing seasons),

depth limitations (3 feet for soil and 10 feet for ground

water), and the possibility of contaminant entrance into

the food chain through animal consumption of plant

material.

Phytoremediation: Using Green Plants to Clean Up

Contaminated Soil, Groundwater, and Wastewater

Negri, M. C. and Hinchman, R.R.

9 pp 1996

Phytoremediation, an emerging cleanup technology for

contaminated soils, ground water, and wastewater that

is both low-tech and low-cost, is defined as the

engineered use of green plants to remove, contain, or

render harmless such environmental contaminants as

heavy metals, trace elements, organic compounds, and

radioactive compounds in soil or water. Current

research at Argonne National Laboratory includes a

successful field demonstration of a plant bioreactor for

processing the salty wastewater from petroleum wells

and a greenhouse experiment on zinc uptake in hybrid

poplar (Populus sp.). Because the roots sequester most

of the contaminant taken up in most plants, a major

objective of this program is to determine the feasibility

of root harvesting as a method to maximize the removal

of contaminants from soils. Available techniques and

equipment for harvesting plant roots, including young

tree roots, are being evaluated and modified as

necessary for use.

Remediation Technologies Screening Matrix and

Reference Guide

Federal Remediation Technologies Roundtable

Available at http://www.frtr.gov

This reference guide provides a "yellow pages" of

remediation technologies. It is intended to be used to

screen and evaluate candidate cleanup technologies for

contaminated installations and waste sites in order to

assist remedial project managers (RPMs) in selecting a

remedial alternative. It incorporates cost and

performance data to the maximum extent available and

focuses primarily on demonstrated technologies. All

levels of remediation technologies are included in this

guide. These technologies are applicable at all types of

site cleanups: Superfund, DoD, DOE, RCRA, state,

private, etc.

Stemming the Toxic Tide

Dutton, G.

Compressed Air v 101:4 p 38(5) June 1996

Phytoremediation, the use of plants to clean up toxic

substances in soil and water, has been proposed as an

effective treatment for contaminated soil and sludge at

industrial locations, including Superfund sites. The

approach represents a cost-effective alternative to

conventional remediation methods. Elements being

considered as targets of phytoextraction include nickel,

zinc, copper, selenium, cadmium, chromium, lead,

cobalt, manganese, and several radionuclides. Specific

plants and processes being used to clean soil and water

are identified. Problems with the approach include

disposal issues and time and depth limitations.
Abstracts of Phytoremediation Resources General Information

6

Technology Evaluation Report: Phytoremediation

Schnoor, J.L.

Ground-Water Remediation Technologies Analysis

Center 

43 pp October 1997

Available at http://www.gwrtac.org

Phytoremediation is best applied at sites with shallow

contamination by organic, nutrient, or metal pollutants.

Phytoremediation is well-suited for use at very large

field sites where other methods of remediation are not

cost-effective or practicable; at sites with low

concentrations of contaminants where only "polishing

treatment" is required over long periods of time; and in

conjunction with other technologies where vegetation is

used as a final cap and closure of the site. There are

limitations to the technology that need to be considered

carefully before it is selected for site remediation. These

include: limited regulatory acceptance, long duration of

time sometimes required for clean-up to below action

levels, potential contamination of the vegetation and

food chain, and difficulty establishing and maintaining

vegetation at some toxic waste sites. This detailed

report discusses the current status of phytoremediation

to treat soils and ground water. Several field

demonstration summaries are presented, with such

information as: participants, compounds treated, site

characteristics, results, and contacts.

Using Phytoremediation to Clean Up Contamination

at Military Installations

Zellmer, S.D.; Hinchman, R.R.; Negri, M.C.;

Schneider, J.F.; and Gatliff, E.G. 

19 pp July 1997 

NTIS Document Number: DE97007971

An emerging technology for cleaning contaminated

soils and shallow ground water is phytoremediation, an

environmentally friendly, low-cost, and low-tech

process. Phytoremediation encompasses all

plant-influenced biological, chemical, and physical

processes that aid in the uptake, degradation, and

metabolism of contaminants by either plants or

free-living organisms in the plant's rhizosphere. A

phytoremediation system can be viewed as a biological,

solar-driven, pump-and-treat system with an extensive,

self-extending uptake network (the root system) that

enhances the soil and below-ground ecosystem for

subsequent productive use. Argonne National

Laboratory has been conducting basic and applied

research in phytoremediation since 1990.

Publications Containing Multiple Papers

Phytoremediation of Soil and Water Contaminants

Kruger, E.L.; Anderson, T.A.; and Coats, J.R. (eds.)

Developed from a symposium sponsored by the

Division of Agrochemicals and the Division of

Environmental Chemistry at the 212th National

Meeting of the American Chemical Society, August

25-29, 1996, Orlando, Florida.

American Chemical Society, Washington, DC 318 pp

1997

Emerging Technologies in Hazardous Waste

Management VII: The 7th ACS Special Symposium,

17-20 September 1995, Atlanta, Georgia

Tedder, D.W. (ed.)

American Chemical Society, Washington, DC 1352 pp

1995

Bioremediation Through Rhizosphere Technology

Anderson, T.A. and Coats, J.R. (eds.) 

American Chemical Society, Washington, DC 249 pp

1994

Bioremediation of Surface and Subsurface

Contamination (Annals of the New York Academy

of Sciences, Vol. 829) 

Bajpai, R. and Zappi, M. (eds.) 

1997 

In Situ and On-Site Bioremediation, Vol. 3

Alleman, B.C. and Leeson, A. (eds.)

Battelle Press, Columbus, OH 570 pp 1997
Abstracts of Phytoremediation Resources Organic Contaminants

7

Proceedings of the Annual Conference on Hazardous

Waste Research

Great Plains/Rocky Mountain Hazardous Substance

Research Center, Kansas State University, Manhattan,

KS

Tables of contents, abstracts, and selected papers from

the 1994 Ninth Annual Conference onward are

available at http://www.engg.ksu.edu/HSRC

Proceedings of the International Seminar on Use of

Plants for Environmental Remediation (ISUPER) 

Council for Promotion of Utilization of Organic

Materials (CPOUM), Kosaikan, Tokyo, Japan 1997

Annual International Conference on

Phytoremediation

International Business Communications,

Southborough, MA (1st:1996, 2nd:1997, 3rd:1998)

Proceedings of the 12th Annual Conference on

Contaminated Soils: Analysis, Site Assessment, Fate,

Environmental and Human Risk Assessment,

Remediation and Regulation, 20-23 October 1997,

Amherst, MA 

Kostecki, P. T. and Calabrese, E.J. (eds.)

Environmental Health Sciences Program, School of

Public Health, University of Massachusetts, Amherst,

MA, 1997

Journal of Soil Contamination

v 7:4 July 1998

Soil & Groundwater Cleanup

February-March 1999

Soil & Groundwater Cleanup

February-March 1998

International Journal of Phytoremediation

First Issue (v 1:1) to be published by CRC Press in

March 1999.

Phytoremediation

Terry, N. and Bañuelos, G.S. (eds.)

Ann Arbor Press, (In press. Release expected Summer

1999).

Superfund Innovative Technology Evaluation

Program: Technology Profiles, 9th Edition

EPA Document Number: EPA 540-R-97-502

Organic Contaminants

Overviews

Mechanisms of Phytoremediation: Biochemical and

Ecological Interactions Between Plants and Bacteria

Siciliano, S.D. and Germida, J.J.

Environmental Reviews v 6:1 p 65(15) 1998

This review concentrates on plant-bacteria interactions

that increase the degradation of hazardous organic

compounds in soil. Plants and bacteria can form

specific associations in which the plant provides the

bacteria with a specific carbon source that induces the

bacteria to reduce the toxicity of the contaminated soil.

Alternatively, plants and bacteria can form nonspecific

associations in which normal plant processes stimulate

the microbial community, which in the course of

normal metabolic activity degrades contaminants in

soil. Plants can provide carbon substrates and nutrients,

as well as increase contaminant solubility. These

biochemical mechanisms increase the degradative

activity of bacteria associated with plant roots. In

return, bacteria can augment the degradative capacity

of plants or reduce the toxicity of the contaminated soil.
Abstracts of Phytoremediation Resources Organic Contaminants

8

Phytoremediation of TCE in Groundwater using

Populus

Chappell, J.

Status Report Prepared for the U.S. EPA Technology

Innovation Office, 1997

Available at http://clu-in.org

This report is intended to provide a basic orientation to

phytoremediation and a review of its use for shallow

ground water remediation. It contains information

gathered from a range of currently available sources,

including project documents, reports, periodicals,

Internet searches, and personal communication with

involved parties. No attempts were made to

independently confirm the resources used. 

Field Studies and Demonstrations

Demonstration Plan for Phytoremediation of

Explosive-contaminated Groundwater in

Constructed Wetlands at Milan Army Ammunition

Plant, Milan, Tennessee. Volumes 1 and 2. Final

Report

Behrends, L.; Sikora, F.; Kelly, D.; Coonrod, S.; and

Rogers, B.

209 pp (Vol. 1), 496 pp (Vol. 2) Jan 1996

NTIS Document Number: ADA311121/8/XAB (Vol. 1)

ADA311122/6/XAB (Vol. 2)

This plan demonstrates the technical and economic

feasibility of using phytoremediation in an artificial,

constructed wetlands for treatment of

explosives-contaminated ground water at Milan Army

Ammunition Plant. Validated data on cost and

effectiveness of this demonstration will be used to

transfer this technology to the user community.

Evaluation of Various Organic Fertilizer Substrates

and Hydraulic Retention Times for Enhancing

Anaerobic Degradation of Explosives-Contaminated

Groundwater While Using Constructed Wetlands at

the Milan Army Ammunition Plant, Milan,

Tennessee

Behrends, L.L.; Almond, R.A.; Kelly, D.A.; Phillips,

W.D.; and Rogers, W.J.

383 pp May 1998 

NTIS Document Number: ADA349293 

This document describes studies conducted at the Milan

Army Ammunition Plant (MAAP) to improve the

design, operation, and cost of gravel-based anaerobic

cells when phytoremediating explosives-contaminated

ground water. A typical gravel-based wetland consists

of an anaerobic cell for removing the bulk of the

explosive-contaminates, and an aerobic cell for

removing CBOD-5, nutrients, total suspended solids,

and small quantities of explosive by- products. The

cells are connected in series with the anaerobic cell

being the first cell. Small-scale anaerobic test cells were

used to determine: (1) If the hydraulic retention time of

a large demonstration-scale anaerobic cell at MAAP

could be reduced, and (2) if other carbon sources could

be used as an anaerobic feedstock. The study results

indicate that: (1) The existing anaerobic cell's 7.5-day

retention time should not be reduced since residual

explosive by-products were present in the effluent of

treatments with a 3.5-day retention time. (2) Daily

application of a relatively soluble substrate, such as

molasses syrup, will provide better explosives removal

than periodic application of less soluble substrates such

as milk replacement starter and sewage sludge.

Field Scale Evaluation of Grass-Enhanced

Bioremediation of PAH Contaminated Soils

Sorensen, D.L.; Sims, R.C.; and Qiu, X.

EPA Risk Reduction Engineering Laboratory’s 20th

Annual Research Symposium, 15-17 March 1994,

Cincinnati, OH p 92(3)

A field pilot-scale study was launched to assess the

potential of prairie grasses to enhance bioremediation

of PAH-contaminated soils. The ongoing research is

designed to test the hypothesis that the deep, fibrous

root system of the grasses improves aeration in soil and

degradative capability in the rhizosphere. Average

phenanthrene levels declined dramatically in both

vegetated and unvegetated plots. Acenaphthylene also

declined in both sites with time and was detected in

higher concentrations in unvegetated shallow soil

relative to vegetated shallow soil. Preliminary data

indicate slow degradation in test plots and provide

some evidence that Buffalo grass sod planting

enhanced degradation in the near surface.
Abstracts of Phytoremediation Resources Organic Contaminants

9

Friendly Forests

Miller, J. A.

Third International Conference on Health, Safety,

Environment in Oil and Gas Exploration and

Production, 9 June-12 Sep 1996, New Orleans,

Louisiana

Society of Petroleum Engineers (SPE), Inc.,

Richardson, TX p 717(6) 1996

Trees can be used to extract ground water from aquifers

and serve as a natural pumping system for

contaminated ground water plume control.

Simultaneously, the trees create a rhizosphere

biodegradation zone and extract hydrocarbons through

uptake in the transpiration stream. Phytoremediation

has been proposed for 

cleanup of historical petroleum hydrocarbon and

chlorinated hydrocarbon contamination as an in situ

treatment method of reasonable cost that requires little

maintenance. The initiative of one major oilfield

service company at a Louisiana site is described. The

demonstration began in June 1995 with the planting of

92 hybrid poplar trees for the purposes of (1)

controlling ground water movement; (2) taking up

constituents from soil and ground water; and (3)

enhancing bioremediation of soil and ground water in

the rhizosphere. Results to date are reported.

Groundwater Phytoremediation Test Facility,

University of Washington

Contact: Stuart E. Strand, Research Associate Professor

Box 352100, College of Forest Resources, University of

Washington, Seattle, WA 98195

Tel/Fax: 206-543-5350 E-mail:

sstrand@u.washington.edu

The Ground water Phytoremediation Test Facility

(GWPTF) was constructed in 1994 in Fife,

Washington. The facility covers about one-quarter acre

and is equipped with 12 double-lined test beds, each 12

ft x 18 ft x 4.5 ft deep. The site has equipment for

handling, mixing, and delivering synthetically

contaminated water and for decontaminating the

effluent water using carbon adsorption units. The test

facility has been used to provide the first near-full-scale

testing of phytoremediation of chlorinated

hydrocarbons in ground water. Results indicate nearly

complete uptake of TCE and carbon tetrachloride by

poplar trees with no detectable TCE or CT emissions.

The GWPTF test beds allow easy monitoring of

influent and effluent mass fluxes of chlorinated

solvents. A permit is required to conduct

demonstrations. Technology developers and the site

manager work together to file the permit. It takes about

six months to obtain a permit. State and local

regulations apply. Permission to add injectants for

remediation may be granted on a case-by-case basis.

Phreatophyte Influence on Reductive Dechlorination

in a Shallow Aquifer Containing TCE

Lee, R.W.; Jones, S.A.; Kuniansky, E.L.; Harvey, G.J.;

and Eberts, S.M.

Bioremediation and Phytoremediation: Chlorinated

and Recalcitrant Compounds

Battelle Press, Columbus, OH p 263(6) 1998

At Carswell Field, Fort Worth Naval Air Station Joint

Reserve Base in Texas, a phytoremediation

demonstration project is being conducted to determine

if eastern cottonwood trees are effective in remediating

shallow trichloroethylene-contaminated ground water.

Two tree plots were prepared and planted in April

1996, and baseline sampling began shortly thereafter.

A stand of whips (cuttings) and a stand of 1- to

2-year-old trees are included in the study. After 18

months, the root systems were not sufficiently

established to alter the chemistry and microbiology of

the ground water. However, a nearby mature

cottonwood tree was found to have changed ground

water chemistry, causing oxygen consumption, iron

reduction, methane production, and reductive

dechlorination of TCE in the vicinity of the root

system. Ground water levels and TCE concentrations in

the aquifer will be monitored to establish baseline

conditions and to map changes within the aquifer

throughout the life of the demonstration. Costs

associated with the planting and cultivation of each tree

stand will be compared to help assess the practicability

of phytoremediation as a cleanup technology.

Demonstration sampling will continue until the year

2000.
Abstracts of Phytoremediation Resources Organic Contaminants

10

Phytoremediation of Dissolved-Phase

Trichloroethylene Using Mature Vegetation

Doucette, W.J.; Bugbee, B.; Hayhurst, S.; Plaehn,

W.A.; Downey, D.C.; Taffinder, S.A.; and Edwards, R.

Bioremediation and Phytoremediation: Chlorinated

and Recalcitrant Compounds

Battelle Press, Columbus, OH p 251(6) 1998

At a study site at Cape Canaveral Air Station, FL,

transpiration gas and tissues of live oak, castor bean,

and saw palmetto growing above a trichloroethylene

(TCE)-contaminated ground water plume were

collected and analyzed for TCE and its metabolites.

Results showed that measurable levels of TCE were

detected in seven of 15 transpiration-gas samples.

Trichloroethylene, 2,2,2-trichloroethanol,

2,2,2-trichloroacetic acid, and 2,2-dichloroacetic acid

were detected in all plant tissue types from all three

species. Generally, metabolite concentrations were

higher than TCE concentrations. Highest TCE

concentrations were found in the roots, while highest

metabolite concentrations were detected in leaf and

stem samples.

Phytoremediation of Groundwater at Avesta

Sheffield Pipe 

Glanders, G.A. and Lundquist, J.B.

Iron and Steel Engineer v 75:5 p 39(3) May 1998

Ground water contaminated with volatile organic

compounds and nitrate from spent pickle liquor is

being remediated by a phytoremediation process using

limpograss. Limpograss is a high protein,

nitrate-loving grass that also serves as a valuable source

of animal feed.

Phytoremediation of Organic and Nutrient

Contaminants

Schnoor, J.L.; Licht, L.A.; McCutcheon, S.C.; Wolfe,

N.L.; and Carreira, L.H.

Environmental Science & Technology v 29:7 p 318A(6)

1995

Phytoremediation, the use of vegetation for the in situ

treatment of contaminated soils and sediments, is an

emerging technology that promises effective and

inexpensive cleanup of certain hazardous waste sites.

Remediation using plants is best suited to sites with

shallow contamination (<15 ft depth); moderately

hydrophobic pollutants (BTEX compounds, chlorinated

solvents, nitrotoluene ammunition wastes), or excess

nutrients (nitrate, ammonium, and phosphate). The

technology has been used effectively in a number of

full-scale and pilot studies that are mentioned in the

article.

Pilot-Scale Use of Trees to Address VOC

Contamination

Compton, H.R.; Haroski, D.M.; Hirsh, S.R.; and

Wrobel, J.G.

Bioremediation and Phytoremediation: Chlorinated

and Recalcitrant Compounds

Battelle Press, Columbus, OH p 245(6) 1998

At the Aberdeen Proving Ground, MD, significant

levels of VOCs have been detected in the ground water,

primarily in the surficial aquifer, at depths to

approximately 12 m. A study was conducted to assess

phytoremediation as a viable alternative for

remediating the shallow ground water contamination.

Over a 4000-m2

 plot, 183 hybrid poplar trees were

planted, and seasonal transpiration gas and water

samples were analyzed. The data revealed that the trees

were removing or degrading VOCs at the site as

indicated by the presence of VOCs and their

degradation products in transpiration gas, condensate,

and leaf tissue. A gradient of ground water flow has

formed toward the phytoremediation test plot, with a

ground water depression of approximately 0.1 m.

Analysis of nematode samples suggested that the soil

habitat is improving due to the presence of the trees.

Screening of Aquatic and Wetland Plant Species for

Phytoremediation of Explosives-Contaminated

Groundwater from the Iowa Army Ammunition

Plant. Final Report

Best, E.P.; Zappi, M.E.; Fredrickson, H.L.; Sprecher,

S.L.; and Larson, S.L.

74 pp January 1997

NTIS Document Number: ADA322455/7/XAB
Abstracts of Phytoremediation Resources Organic Contaminants

11

Munitions material such as 2,4,6-trinitrotoluene (TNT)

and hexahydro-1,3,5- trinitro-1,3,5-triazine (RDX) and

their combustion and decomposition products can enter

the environment from production activities, field usage,

and disposal. The capabilities of plants to absorb,

accumulate, and metabolize, directly or indirectly,

various organic substances suggest their use in the

phytoremediation of contaminated environments.

Screening Submersed Plant Species for

Phytoremediation of Explosives-Contaminated

Groundwater from the Milan Army Ammunition

Plant, Milan, Tennessee. Final Report

Best, E.P.; Sprecher, S.L.; Fredrickson, H.L.; Zappi,

M.E.; and Larson, S.L.

89 pp November 1997

Phytoremediation systems are being considered as an

alternative to other ground water extraction and surface

treatment techniques due to their ability to enhance

removal of potentially toxic or mutagenic munitions

material such as 2,4,6-trinitrotoluene (TNT),

hexahydro-1,3,5- trinitro-1,3,5-triazine (RDX), and

their degradation products. This study evaluated the

relative ability of ten species to decrease levels of TNT

and RDX explosives and related contaminants in

ground water at the Milan Army Ammunition Plant,

Milan, Tennessee.

Research

Adsorption of Naphthalene onto Plant Roots

Schwab, A. P.; Al-Assi, A. A.; and Banks, M. K.

Journal of Environmental Quality v 27:1 p 220(5)

January-February 1998

During phytoremediation, PAHs that are resistant to

degradation may adsorb to the surfaces of plant roots,

making the roots an important sink for specific PAHs.

Tall fescue and alfalfa were grown in a greenhouse

under controlled conditions, and roots were harvested

at three growth stages: vegetative, flowering, and

mature. Naphthalene adsorption to the various plant

roots was then evaluated. Results show that the mass of

naphthalene volatilized was the largest component of

the mass balance (32-45%). The mass in solution was

usually greater than that adsorbed to the roots. The

affinity of naphthalene for alfalfa roots was greater than

that for tall fescue roots, but fescue roots were present

in much greater quantities in the soil compared with

alfalfa. Naphthalene adsorption on the roots of both

plant species increased with plant age.

Aromatic Nitroreduction of Acifluorfen in Soils

Rhizospheres and Pure Cultures of Rhizobacteria

Zablotowicz, R.M.; Locke, M.A.; and Hoagland, R.E.

Agricultural Research Service September 1996

Reduction of the nitro group in acifluorfen (a

nitrodiphenyl ether herbicide) to aminoacifluorfen is a

major catabolic transformation of this herbicide in

soils, rhizospheres, and pure cultures of certain

bacteria. Aromatic nitroreduction occurs more rapidly

in rhizosphere soils compared to root-free soil, with a

rapid incorporation into unextractable humic soil

components. Factors affecting acifluorfennitroreductase activity in cell suspensions and cell-free

extracts of these bacteria were studied. Microbial

aromatic nitroreductase activity in soils and

rhizospheres can be an important biotransformation in

the degradation of acifluorfen and other nitroaromatic

herbicides. 

Bacterial Inoculants of Forage Grasses That

Enhance Degradation of 2-Chlorobenzoic Acid in

Soil

Siciliano, S.D. and Germida, J.J.

Environmental Toxicology and Chemistry v16:6 p

1098(7) June 1997

A study was conducted to examine the potential of

rhizosphere inoculants to enhance the degradation of

contaminants in soil. 2-Chlorobenzoic acid was used as

the model contaminant, along with 11 bacterial strains

and 16 forage grass species. Results showed that three

of the forage species—Bromus biebersteinii, Elymus

dauricus, and Agropyron riparum—grew well in the

2-chlorobenzoic acid-contaminated soil and also

enhanced the disappearance of the compound. The best

bacterial inoculants proved to be Pseudomonas

aeruginosa strain R75 and P. savastoanoi strain CB35.

The inoculation of the forage grasses with either

bacterial strain increased significantly the
Abstracts of Phytoremediation Resources Organic Contaminants

12

disappearance of 2-chlorobenzoic acid over that of

unplanted controls. 

Bioremediation Bacteria to Protect Plants in

Pentachlorophenol-Contaminated Soil

Pfender, W.F.

Journal of Environmental Quality v 25:6 p 1256(5)

November-December 1996

Pseudomonas strain SR3, a known pentachlorophenoldegrader, was added to a pentachlorophenolcontaminated soil, and the ability of the bacteria to

protect Proso millet sown in the soil was 

assessed. Plants were removed from the soil 28 days 

after planting with roots, shoots, and soil analyzed for

pentachlorophenol. Seedling emergence was found to

be 50 and 62% for bacteria-treated and control seeds,

respectively, in pentachlorophenol-contaminated soil.

In uncontaminated soil, emergence rates were 100 and

87%, respectively. Bacterial treatment greatly increased

final plant biomass in contaminated soil, bringing root

and total plant weights to nearly the same as those

observed for plants grown in uncontaminated soil. In

contaminated soil planted with bacteria-treated seeds,

the final pentachlorophenol level was only 3 mg/kg, as

compared to 5 and 157 mg/kg for the millet-only and

nonplanted contaminated soils, respectively.

Decreased Transpiration in Poplar Trees Exposed to

2,4,6-Trinitrotoluene

Thompson, P.L.; Ramer, L.A.; Guffey, A.P.; and

Schnoor, J.L.

Environmental Toxicology & Chemistry v 17:5 p

902(5) May 1998

Poplar trees were exposed to 2,4,6-trinitrotoluene

(TNT), and the effects on transpiration were examined.

The TNT concentrations used were 0, 1, 3, 5, 10, and

15 mg/l. Levels of TNT uptake reached the detection

limit of 4 ppm after only 1 hour of exposure, with TNT

removed at a relatively rapid rate. TNT concentrations

of greater than 5 mg/l were toxic to the trees, with the

decrease in biomass attributed to the inhibition of leaf

growth. This level decreased transpiration significantly

after 11 days of exposure. Overall, the hybrid poplar

exhibited a tolerance for TNT that was higher than that

of duckweed and similar to that of yellow nutsedge.

Degradation of Polychlorinated Biphenyls by Hairy

Root Culture of Solanum nigrum

Mackova, M.; Macek, T.; Kucerova, P.; Burkhard, J.;

Pazlarova, J.; and Demnerova, K.

Biotechnology Letters v 19:8 p 787(4) August 1997

Hairy root cultures of Solanum nigrum proved capable

of transforming PCBs under controlled conditions. The

impact of several different plant growth regulators on

cell growth and transformation of PCBs are analyzed.

Plant cells proved capable of transforming PCBs even

after growth had stopped. A 20% reduction in PCB

conversion efficiency was observed in young inoculum

(16 days), as compared against older inocula (37 and

68 days). The PCB transformation rate was stimulated

with increasing size of inoculum.

Detoxification of Phenol by the Aquatic Angiosperm,

Lemna gibba

Barber, J.T.; Sharma, H.A.; Ensley, H.E.; Polito, M.A.;

and Thomas, D.A.

Chemosphere v 31:6 p 3567(8) September 1995

In many cases, plants have the ability to metabolize

organic pollutants by transformation and conjugation

reactions followed by compartmentalizing products in

their tissues. The toxicity and fate of phenol in the

angiosperm Lemna gibba were investigated. Over a 16

day growth period, almost 90% of the applied phenol

disappeared from solution. While the disappearance of

phenol was attributed to plant uptake, the appearance of

additional compounds in the media indicated that

metabolism occurred, with the release of the

metabolites back to the media. The primary metabolite

was identified as phenyl-(gr)b-D-glucoside, which was

found to be approximately half as toxic as the parent

compound.
Abstracts of Phytoremediation Resources Organic Contaminants

13

Effect of Hybrid Poplar Trees on Microbial

Populations Important to Hazardous Waste

Bioremediation

Jordahl, J.L.; Foster, L.; Schnoor, J.L.; and Alvarez,

P.J.J.

Environmental Toxicology and Chemistry v 16:6 p

1318(4) June 1997

Microbial populations from the rhizosphere of

seven-year-old hybrid poplar trees were characterized

in terms of five specific phenotypes: total heterotrophs;

denitrifiers; pseudomonads; degraders of benzene,

toluene, and xylenes (BTX); and atrazine degraders.

The concentrations of these phenotypes were measured

in three rhizosphere samples and in three control soil

samples taken from an adjacent corn field. All types of

microbial populations were higher in the poplar

rhizosphere than in the surrounding soil. Highest

concentrations were found for total heterotrophs,

followed by denitrifiers, pseudomonads, BTX

degraders, and atrazine degraders. These findings are

discussed in relation to bioremediation potential.

Effects of Ryegrass on Biodegradation of

Hydrocarbons in Soil

Gunther, T.; Friedrich-Schiller-Universitat J.;

Dornberger, U.; and Fritsche, W.

Chemosphere v 33:2 p 203(13) July 1996

The influence of ryegrass on the biodegradation of

applied aliphatics and PAHs was investigated using a

series of laboratory soil-column experiments. A defined

mixture of saturated, unsaturated, and branched-chain

aliphatics and PAHs was added to the soil columns.

Results show that the artificially applied aliphatic

hydrocarbons disappeared faster and to a greater extent

in ryegrass-planted columns than in the non-root

systems. The enhanced disappearance of the pollutants

in the rhizosphere was accompanied by higher values

for microbial plate counts and soil respiration rates for

the vegetated systems, which indicated the primary role

of microbial degradation. In contrast to the aliphatics,

the amount of PAHs decreased rapidly in both systems,

and the differences between planted and unplanted soil

were insignificant.

A Field Facility for Phytoremediation Research

Rhykerd, R.L.; Hallmark, M.T.; and Munster, C.L.

The 1998 ASAE Annual International Meeting, 11-16

July 1998, Orlando, Florida 

American Society of Agricultural Engineers, St.

Joseph, MI 1998

A recently developed phytoremediation computer

model may be extremely useful in predicting the fate of

recalcitrant hydrocarbons in soil. A field facility for

phytoremediation research has been constructed to

provide empirical data to validate and calibrate the

model. Trinitrotoluene (TNT);

2,2',5,5'-tetrabromobiphenyl (PBB); and chrysene have

been tested. Due to the hazardous nature of these

hydrocarbons, the soil-contaminant mixture was

isolated from the field environment using two lysimeter

designs. Soil in both the box and column lysimeters

were contaminated with 10 mg of each contaminant per

kg of soil. Vegetation treatments consisted of fallow,

warm season grass (Johnsongrass), cool season grass

(Canadian wild-rye grass), and a warm/cool season

grass rotation (Johnsongrass/Canadian wild-rye grass).

Both the box and column lysimeters functioned well in

collecting parameters necessary to validate and

calibrate the computer model.

Greenhouse Evaluation of Agronomic and Crude

Oil-Phytoremediation Potential Among Alfalfa

Genotypes

Wiltse, C. C.; Rooney, W. L.; Chen, Z.; Schwab, A. P.;

and Banks, M. K.

Journal of Environmental Quality v 27:1 p 169(5)

January-February 1998

Twenty alfalfa plants were evaluated in terms of their

agronomic performance and phytoremediation potential

for crude oil-contaminated soil. Among the genotypes,

differences were observed in total forage yield,

maturity, plant height, and leaf-burn rating. Total

petroleum hydrocarbon concentrations in soil after 12

months ranged 3799-5754 mg/kg for soils with the

alfalfa plants and averaged 4610 mg/kg in the

unvegetated control. When each genotype was

considered separately, two genotypes had total

petroleum hydrocarbon concentrations that were

significantly lower than that of the unvegetated control.

Plants growing in contaminated soil, however,
Abstracts of Phytoremediation Resources Organic Contaminants

14

exhibited later maturation and shorter heights than

those growing in uncontaminated soil.

The Influence of Planting and Soil Characteristics

on Mineralization of 2,4,5-T in Rhizosphere Soil

Boyle, J.J. and Shann, J.R.

Journal of Environmental Quality v 27:3 p 704(6)

May-June 1998

Soils from an abandoned pasture, a forest, and a

floodplain near Cincinnati, OH, were used as substrate

for timothy grass, red clover, and sunflower, and

evaluated in terms of their mineralization of

2,4,5-trichlorophenoxyacetic acid (2,4,5-T). Microbial

activity, biomass, and mineralization of 2,4,5-T in

rhizosphere soil were determined before and after

planting. Results showed that microbial activity and

biomass were dependent upon soil type in the unplanted

plots. In soils with lower values, planting significantly

increased biomass and/or activity, independent of plant

species. Overall, soil type was the most significant 

determinant of microbial biomass, activity, and

xenobiotic degradation.

Mineralization of 2,4-Dichlorophenol by

Ectomycorrhizal Fungi in Axenic Culture and in

Symbiosis with Pine

Meharg, A.A.; Cairney, J.W.G.; and Maguire, N.

Chemosphere v 34:12 p 2495(10) June 1997

The fungal mycelium associated with mycorrhizal

plants provides a means of enhancing the volume of

rhizospheric soil compared to bulk soil, which can

enhance soil remediation. Two ectomycorrhizal fungal

species—Suillus variegatus and Paxillus

involutus—were evaluated in terms of their ability to

degrade 2,4-dichlorophenol in batch culture and in

association with Pinus sylvestris. Results indicate that

2,4-dichlorophenol was readily degraded by both

species, but P. involutus proved to be much more

efficient than S. variegatus. In the presence of pine

seedlings, mycorrhizal symbiosis increased

mineralization by both species, but the increase was

much more dramatic for S. variegatus, which under

these conditions became the more efficient degrader of

2,4-dichlorophenol.

Phytoremediation Experimentation with the

Herbicide Bentazon

Conger, R.M. and Portier, R.J.

Remediation v 7:2 p 19(19) 1997

An experiment was performed on six species of trees to

determine the feasibility of remediating ground water

contaminated with an agricultural herbicide, bentazon,

at a site in southern Louisiana. Fate studies on

bentazon support that it is translocated to the plant

leaves where it is degraded to lower-order derivative

compounds within short periods of time. Both

transpiration observations and dosing tests suggest that

both the most favorable phreatophyte and species

tolerant of bentazone exposure was the black willow

(Salix nigra).

Phytoremediation: Modeling Removal of TNT and

Its Breakdown Products

Medina, V.F. and McCutcheon, S.C.

Remediation v 7:1 p 31(15) Winter 1996

The success of phytoremediation techniques for the

treatment of TNT-contaminated ground water and

wastewater is evaluated. Two different

phytoremediation techniques are examined: controlled

reactors and constructed wetlands. The benefits offered

by controlled reactors include: greater control over

operating parameters, reduced chances of contaminant

migration, and reduced chances that animals will feed

on the plants. Constructed wetlands are generally less

expensive and often provide aesthetic and ecological

benefits. A first-order, nonreversible reaction,

plug-flow, finite-difference model was used to predict

the disappearance of TNT from a constructed wetland.

Phytoremediation of 1,4-dioxane by Hybrid Poplars

Aitchison, E.W.; Schnoor, J.L.; Kelley, S.L.; and

Alvarez, P.J.J.

Proceedings of the 12th Annual Conference on

Hazardous Waste Research, 20-22 May 1997, Kansas

City, Missouri

The suspected carcinogen 1,4-dioxane has a half-life in

soils and ground water of several years, while its

half-life in the atmosphere in the presence of NO and
Abstracts of Phytoremediation Resources Organic Contaminants

15

hydroxyl radicals is several hours. The researchers 

examine 1,4-dioxane volatilization into the atmosphere

via plant transpiration, evaluating the capacity of

rooted cuttings of hybrid poplar trees to take up and

translocate 1,4-dioxane. Study results indicate that

poplar uptake of 1,4-dioxane far exceeds its

degradation by indigenous root-zone microorganisms.

The majority of 1,4-dioxane taken up into the plant was

volatilized, with the remaining mass concentrated

primarily in the stem. Rapid uptake of 1,4-dioxane by

hybrid poplar trees makes phytoremediation an

attractive treatment alternative at

dioxane-contaminated sites, and research into this

treatment methodology will continue. 

Phytoremediation of Hazardous Wastes

McCutcheon, S.C.; Wolfe, N.L.; Carreria, L.H.; and

Ou, T.Y.

Innovative Technologies for Site Remediation and

Hazardous Waste Management: Proceedings of the

National Conference, 23-26 July 1995, Pittsburgh,

Pennsylvania

American Society of Civil Engineers, New York, NY p

597(8) 1995

Analyzing the effectiveness of phytoremediation

involves rigorous pathway analyses, mass balance

determinations, and identification of specific enzymes

that break down trinitrotoluene (TNT), other explosives

(RDX and HMX), nitrobenzene, and chlorinated

solvents (such as TCE and PCE). For example, TNT is

completely and rapidly degraded by nitroreductase and

laccase enzymes. As part of the natural lignification

process, the aromatic ring is broken and the carbon in

the ring fragments is incorporated into new plant fiber.

The use of created wetlands and other

phytoremediation applications guided by rigorous field

biochemistry and ecology promises to be a vital part of

a newly evolving field, ecological engineering.

Phytoremediation of Organic Contaminants: A

Review of Phytoremediation Research at the

University of Washington

Newman, L.A.; Doty, S.L.; Gery, K.L.; Heilman, P.E.;

et al.

Journal of Soil Contamination, v 7:4, p 531(12), 1998

Studies to determine the potential for phytoremediation

of fully chlorinated compounds, brominated

compounds, and nonhalogenated compounds are

underway. When using phytoremediation, it is

important to select not only a plant that is capable of

degrading the pollutant in question, but also one that

will grow well in that specific environment. One way to

supplement the arsenal of plants available for remedial

actions is to utilize genetic engineering tools to insert

into plants those genes that will enable the plant to

metabolize a particular pollutant. Hybrid technologies,

such as using plants in pumping and irrigation systems,

also enable plants to be used as a remedial method

when the source of the pollutant is beyond the reach of

plant roots, or when planting space directly over the

pollutant is unavailable or restricted. Thus, the

potential uses of phytoremediation are expanding as the

technology continues to offer new, low-cost remediation

options.

Phytoremediation of Pesticide-Contaminated Soils

Kruger, E.L.; Anderson, T.A.; and Coats, J.R.

Air & Waste Management Association’s 89th Annual

Meeting, 1996, Nashville, Tennessee

Available at http://www.awma.org

Screening tests of rhizosphere soils from 15 plant

species were conducted to determine their ability to

mineralize two common herbicide contaminants:

atrazine and metolachlor. Mineralization of

14C-atrazine or 14C-metolachlor, applied at 50 ppm

each, was monitored. Kochia rhizosphere soil exhibited

the greatest mineralization of 14C-atrazine. Other

rhizosphere soils that exhibited the ability to mineralize

high concentrations of atrazine included musk thistle,

catnip, foxtail barley, witchgrass, and lambsquarters.

None of the rhizosphere soils tested exhibited a positive

response for 14C-metolachlor mineralization.

Mineralization of atrazine was considerable after 36

days, while mineralization of metolachlor was minimal.

The percentage of extractable atrazine for kochia

vegetated soils was significantly less than from

nonvegetated soil. Combustion of plants revealed that

11% of the applied 14C was taken up by kochia. This

research indicates that the use of plants in remediating

soils looks promising.
Abstracts of Phytoremediation Resources Organic Contaminants

16

Phytoremediation of Trichloroethylene with Hybrid

Poplars

Gordon, M.; Choe, N.; Duffy, J.; Ekuan, G.; Heilman,

P.; Muiznieks, I.; Newman, L.; Ruszaj, M.; Shurtleff,

B.B.; Strand, S.; and Wilmoth, J.

Phytoremediation of Soil and Water Contaminants

American Chemical Society, Washington, DC p 177(9)

1997

The ability of hybrid plants to absorb trichloroethylene

(TCE) from ground water was examined. Initial studies

used axenic tumor cultures of H11-11 grown in the

presence of 14C-TCE. These cells metabolized the TCE

to produce trichloroethanol, di- and trichloroacetic

acid. Some of the TCE was incorporated into insoluble,

non-extractable cell residue, and small amounts were

mineralized to 14C-CO2. Rooted poplar cuttings grown

in PVC pipes produced the same metabolites when

exposed to TCE. Mass balance studies indicate that the

poplars also transpire TCE. In addition one of the first

controlled field trials for this technology is being

conducted. Trees were planted in cells lined with high

density polyethylene and exposed to TCE via an

underground water stream during the growing season.

Cells containing trees had significantly reduced TCE

levels in the effluent water stream compared to control

cells containing only soil. These results show that

significant TCE uptake and degradation occur in

poplars.

Phytoremediation, Plant Uptake of Atrazine and

Role of Root Exudates

Burken, J.G. and Schnoor, J.L.

Journal of Environmental Engineering v 122:11 p

958(6) 1996

The potential of phytoremediation in the cleanup of

contaminated sites and prevention of non-point-source

pollution was examined with the pesticide atrazine in

two experimental systems. Uptake was determined in

batch experiments with 14C ring-labeled atrazine and

hybrid poplar trees grown in two soil types.

Mineralization was studied utilizing soil microcosms

with the addition of root exudates. Results indicate that

poplar cuttings were able to uptake the majority of

applied atrazine that was not tightly sorbed to the

organic fraction of the soil, with no detectable adverse

effects to the trees. The addition of root exudate to

microcosms showed slight stimulation and the addition

of ground-up root biomass revealed large stimulation of

mineralization to 14CO2. This research indicates that

vegetative uptake and degradation in the rhizosphere

can play a major role in remediation at hazardous waste

sites.

Phytotreatment of TNT-Contaminated Groundwater

Rivera, R.; Medina, V.F.; Larson, S.L.; and

McCutcheon, S.C.

Journal of Soil Contamination, v 7:4, p 511(20), 1998

Phytoremediation is a viable technique for treating

munitions-contaminated ground water and wastewater.

Continuous flow reactor studies were conducted at three

different influent concentrations of 2,4,6-trinitrotoluene

(TNT): 1, 5, and 10 ppm. Retention times varied from

12 to 76 days. Batch experiments were conducted to

confirm the phytodegradation of amino-derivatives of

TNT. Plant tissue was analyzed for TNT and

breakdown products. Preliminary batch studies were

also conducted on the degradation of RDX. Initially,

the control removed TNT as efficiently as the plant

reactors. However, as time continued, the efficiency of

the control dipped below that of the plant reactors,

suggesting that adsorption was initially the mechanism

of removal. Up to 100% of the TNT was removed.

Batch studies found that ADNT and

diaminonitrotoluene (DANT) were phytodegraded. The

batch studies indicated that the degradation of RDX

was slower than that for TNT. Different plants were

more efficient at removing RDX than those for

removing TNT, suggesting that there are differences in

the removal mechanisms.

Plant Cell Biodegradation of a Xenobiotic Nitrate

Ester, Nitroglycerin

Goel, A.; Kumar, G.; Payne, G.F.; and Dube, S.K.

Natural Biotechnology v 15:2 p 174(4) 1997

The ability of plants to metabolize glycerol trinitrate

(GTN, nitroglycerin), was examined using cultured 

plant cells and plant cell extracts. Intact cells rapidly

degrade GTN with the initial formation of glycerol

dinitrate (GDN) and the later formation of glycerol

mononitrate (GMN). Cell extracts were shown to be
Abstracts of Phytoremediation Resources Organic Contaminants

17

capable of degrading GTN with the simultaneous

formation of GDN in stoichiometric amounts. The

degradative activities of plant cells are only ten times

less than those reported for bacterial GTN degradation.

These results suggest that plants may serve a direct

degradative function for the phytoremediation of sites

contaminated by organic nitrate esters.

Plant-Enhanced Remediation of Petroleum

Contaminated Soil

Novak, J.T. and Al-Ghazzawi, Z.

Proceedings of the 1997 29th Mid-Atlantic Industrial

and Hazardous Waste Conference

Technomic Publishing Co., Lancaster, PA p 605(9)

1997

Phytoremediation is an easy and inexpensive method

for treating petroleum-contaminated soils. The

phytoremediation mechanism is related to direct

contaminant uptake or indirect plant mechanisms

which catalyze pollutant-microbe interaction in the

rhizosphere. These mechanisms and their importance

are studied.

Plant-Enhanced Subsurface Bioremediation of

Nonvolatile Hydrocarbons

Chang, Y.Y. and Corapcioglu, M.Y.

Journal of Environmental Engineering v 124:2 p

162(8) February 1998

Phytoremediation has become a promising new area of

research for in situ cleanup of large volumes of slightly

contaminated soils. A model that can be used as a

predictive tool in phytoremediation operations was

developed to simulate the transport and fate of a

residual hydrocarbon contaminant interacting with

plant roots in a partially saturated soil. Time-specific

distribution of root quantity through soil, as well as root

uptake of soil water and hydrocarbon, was incorporated

into the model. In addition, the microbial activity in the

soil rhizosphere was modeled with a biofilm theory.

The simulation results showed enhanced

biodegradation of a hydrocarbon contaminant mostly

because of increased biofilm metabolism of organic

contaminants in a growing root system of cotton.

Simulations also show that a high mean daily

root-water uptake rate increases the contaminant

retardation factors because of the resulting low water

content. The ability to simulate the fate of a

hydrocarbon contaminant is essential in designing

technically efficient and cost-effective, plant-aided

remedial strategies and in evaluating the effectiveness

of a proposed phytoremediation scheme.

Potential of Phytoremediation as a Means for

Habitat Restoration and Cleanup of Petroleum

Contaminated Wetlands

Lin, Q. and Mendelssohn, A.

Phytoremediation of Soil and Water Contaminants 

American Chemical Society, Washington, DC 1997

Oil spills in coastal wetlands often kill vegetation and

contaminate wetland sediment for many years. The

potential of phytoremediation for habitat restoration

and cleanup of contaminated marshes was studied with

marsh mesocosms. Soil sods of Spartina alterniflora

and Spartina patens (common coastal marsh grasses)

were dosed with crude oil. Two years after application

of the oil to the soil sods, these two Spartina species

were transplanted into oiled and unoiled sods to

determine the potential for habitat restoration and oil

phytoremediation. The regrowth biomass was not

significantly affected by oil for combined biomass of

the two species and significantly higher with oil for

Spartina alterniflora, suggesting the potential for

habitat restoration by transplanting after oil spills. Oil

degradation was enhanced by phytoremediation in

combination with fertilization. The oil degradation rate

was negligible in the absence of vegetation, but it was

significantly higher in the presence of transplanted

vegetation and fertilizer. Whether increased

degradation of residual oil was due to the enhancement

of soil microbial activity by the fertilizer or by

phytoremediation is presently being investigated.

Rhizosphere Microbial Populations in Contaminated

Soils

Nichols, T.D.; Wolf, D.C.; Rogers, H.B.; Beyrouty,

C.A.; and Reynolds, C.M.

Water, Air, and Soil Pollution v 95:1-4 p 165(14) 1997
 Abstracts of Phytoremediation Resources Inorganic Contaminants

18

Rhizosphere microbial populations may enhance

bioremediation of soil contaminated with organic

chemicals. A growth chamber study was conducted to

evaluate rhizosphere microbial populations in

contaminated and non-contaminated soil. Alfalfa

(Medicago sativa L.) and alpine bluegrass (Poa alpina

L.) were grown in soil containing a mixture of organic

chemicals for 14 weeks. The equal mixture of

hexadecane, (2,2-dimethylpropyl)benzene,

cis-decahydronaphthalene (decalin), benzoic acid,

phenanthrene, and pyrene was added at levels of 0 and

2000 mg/kg. At nine weeks, the organic chemical

degrader (OCD) populations were significantly higher

in rhizosphere and contaminated soils than in bulk and

non-contaminated soils. Selective enrichment of OCD

populations was observed in contaminated rhizosphere

soil. Higher numbers of OCD in contaminated

rhizospheres suggest potential stimulation of

bioremediation around plant roots.

Transformation of TNT by Aquatic Plants and Plant

Tissue Cultures

Hughes, J. B.; Shanks, J.; Vanderford, M.; Lauritzen,

J.; and Bhadra, R.

Environmental Science & Technology v 31:1 p 266(6)

1997

The ability of plants to uptake and transform

2,4,6-trinitrotoluene (TNT) was investigated using the

aquatic plants Myriophyllum spicatum, axenic

Myriophyllum aquaticum, and Catharanthus roseus

hairy root cultures. Studies demonstrate that both

Myriophyllum and C. roseus transform TNT. Primary

products of transformation were not identified, and

mineralization was not observed. Mass balances

demonstrate that a large percentage of the unknown

TNT transformation products were associated with the

plant. This fraction could be at least partially recovered

from the plant tissue with methanol extraction. A

soluble fraction was also present in the medium. The

formation of soluble, uncharacterized transformation

products is a concern for potential phytoremediation

applications.

Uptake and Fate of Organohalogens from

Contaminated Groundwater in Woody Plants

Sytsma, L.; Mulder, J.; Schneider, J.; et al.

Proceedings of the 213th National Meeting of the

American Chemical Society, 13-17 April 1997, San

Francisco, California

American Chemical Society, Washington, DC p 89

1997

Phytoremediation uses green plants for low-cost,

low-tech remediation processes in which selected plants

and natural or engineered microorganisms work

together to metabolize, convert, absorb, accumulate,

sequester, or otherwise render harmless multiple

environmental contaminants. There is evidence that

plants can degrade a portion of many organic

contaminants and form less volatile compounds which

are sequestered in the plant tissue. The remainder of

the contaminant is passed out of the leaf tissue with the

transpiration stream. Hybrid poplar plants fed by TCEand PCE-spiked nutrient solutions in a greenhouse

showed elevated degradation product levels in the

leaves within a week, as well as evidence for

evapotranspiration of the TCE and PCE.

Publications Containing Multiple Papers

Bioremediation and Phytoremediation: Chlorinated

and Recalcitrant Compounds: the First

International Conference on Remediation of

Chlorinated and Recalcitrant Compounds,

Monterey, California, May 18-21, 1998 

Wickramanayake, G.B. and Hinchee, R.E. (eds.)

Battelle Press, Columbus, OH 301 pp 1998

Inorganic Contaminants

Overviews

Emerging Technologies for the Remediation of

Metals in Soils: Phytoremediation

Interstate Technology and Regulatory Cooperation

Work Group (ITRC), Metals in Soils Work Team 15 pp

1998

Available at http://www.sso.org/ecos/itrc

Phytoremediation is a means of removing organic or

inorganic contaminants from soils, sediments, and

ground water using plants. This document focuses on
 Abstracts of Phytoremediation Resources Inorganic Contaminants

19

issues related to the remediation of metals in soils. The

technology, its applicability to sites and contaminants, 

and associated costs are outlined. Several approaches to

phytoremediation are explored. The document also

presents regulatory and stakeholder concerns and

discusses research needs.

Literature Review: Phytoaccumulation of

Chromium, Uranium, and Plutonium in Plant

Systems

Hossner, L.R.; Loeppert, R.H.; Newton, R.J.; and

Szaniszlo, P.J.

Amarillo National Resource Center for Plutonium, TX

53 pp May 1998 

Phytoremediation is an integrated approach to the

cleanup of contaminated soils that combines the

disciplines of plant physiology, soil chemistry, and soil

microbiology. Removal of metals from contaminated

soils using accumulator plants is the goal of

phytoremediation. The emphasis of this review has

been placed on chromium (Cr), plutonium (Pu), and

uranium (U). With the exception of Cr, these metals

and their decay products exhibit two problems:

radiation dose hazards and their chemical toxicity.

Radiation dose hazards introduce the need for special

precautions in reclamation beyond that associated with

non-radioactive metals. The uptake of metals by plants

occurs predominantly by way of channels, pores, and

transporters in the root plasma membrane. Most

vascular plants absorb toxic and heavy metals through

their roots to varying degrees.

Remediation of Metal-Contaminated Sites Using

Plants

Azadpour, A. and Matthews, J.E.

Remediation v 6:3 p 1(18) 1996

The current technologies employed for removal of

heavy metals from soils often involve expensive ex situ

processes requiring sophisticated equipment for

removal, transportation, and purification of the soil. In

situ bioremediation is receiving increasing attention

because of its relative effectiveness and low cost.

Phytoremediation, a new type of bioremediation, uses

metal-tolerant hyperaccumulator plants to take up

metal ions from soils and store them in the plant itself.

To select the appropriate phytoremediation technology,

the technical feasibility, cost effectiveness, and

availability of the suitable plant species must be

examined. Before phytoremediation can be exploited on

a contaminated site, greenhouse-scale confirmatory

testing is necessary to measure plant uptake and

correlate shoot metal concentrations to available soil

metals. These tests also validate that the harvesting and

subsequent disposal of metal-containing plant tissues

are environmentally safe and manageable.

Restoration of Mined Lands—Using Natural

Processes

Bradshaw, A.

Ecological Engineering v 8:4 p 255(15) August 1997

In many countries legislation now requires that surface

soils disturbed by mining activities be conserved and

replaced, but there is a vast heritage of contaminated

land left by past mining. The processes of natural

succession demonstrate that unaided restoration can be

achieved along with the development of fully

functioning soils. Plants can readily provide organic

matter, lower soil bulk density, bring mineral nutrients

to the surface, and accumulate them in an available

form. Most importantly, some species can fix and

accumulate nitrogen rapidly in quantities more than

adequate for normal ecosystem functioning. Certain

extreme soil conditions may occur that prevent plant

growth, particularly physical conditions, gross lack of

certain nutrients, and toxicity. However, ecosystem

restoration can be achieved at low cost, and the product

be self-sustaining in the long term.

Status of In Situ Phytoremediation Technology

U. S. EPA, Office of Solid Waste and Emergency

Response

Published in Recent Developments for In Situ

Treatment of Metal Contaminated Soils p 31(12)

EPA Document Number: EPA 542-R-97-004

This chapter offers an overview of different

phytoremediation approaches: phytoextraction,
 Abstracts of Phytoremediation Resources Inorganic Contaminants

20

phytostabilization, and rhizofiltration, as well as a

performance and cost summary, applications and future 

development analyses, and a list of metal

hyperaccumulating plants.

Field Studies and Demonstrations

Phytoaccumulation of Trace Elements by Wetland

Plants: I. Duckweed

Zayed, A.; Gowthaman, S.; and Terry, N.

Journal of Environmental Quality v 27:3 p 715(7)

May-June 1998

The removal of trace elements by wetland vegetation is

enhanced by the use of appropriate plant species.

Results are presented from the first in a series of

wetland-plant evaluations in terms of the removal of

trace elements from contaminated water. Duckweed

was considered for its phytoaccumulation of cadmium

(Cd), chromium (Cr), copper (Cu), lead (Pb), nickel

(Ni), and selenium (Se). The data show that Cd was

accumulated to the greatest levels, followed by Se, Cu,

and Cr, and then Pb and Ni.

Relationship Between Sulfur Speciation in Soils and

Plant Availability

Shan, X.-Q.; Chen, B.; Zhang, T.-H.; Li, F.-L.; Wen,

B.; and Qian, J.

Science of the Total Environment v 199:3 p 237(10)

1997

Both bench-scale experiments and field surveys were

conducted to investigate the relationship between sulfur

speciation in soils and sulfur concentration in plants.

Soil sulfur was fractionated into water-soluble sulfate

(S1), adsorbed sulfate (S2), carbonate-occluded sulfate

(S3), ester sulfate (S4) and carbon-bonded sulfur (S5).

Water-soluble sulfate was the most easily available

form of soil sulfur, followed by adsorbed sulfate, ester

sulfate, carbon-bonded sulfur and carbonate-occluded

sulfate. Changes in concentrations of the different

forms of soil sulfur after bench-scale experiments gave

direct evidence to the order of availability. S1 and S2

decreased significantly, S4 also decreased, whereas S5

and S3 remained almost unchanged. These results

suggest that water-soluble and adsorbed sulfate are

directly available to plants, while the mineralization of

sulfate from organic sulfur, especially from ester

sulfate, also contributes to plant uptake of sulfur.

Removal of Uranium from Water Using Terrestrial

Plants

Dushenkov, S.; Vasudev, D.; Kapulnik, Y.; Gleba, D.;

Fleisher, D.; Ting, K.C.; and Ensley, B.

Environmental Science & Technology v 31:12 p

3468(6) December 1997

Uranium (U) contamination of ground water poses a

serious environmental problem in uranium mining

areas and in the vicinity of nuclear processing facilities.

Preliminary laboratory experiments and treatability

studies indicate that the roots of terrestrial plants can be

efficiently used to remove U from aqueous streams

(rhizofiltration). Almost all of the U removed from the

water in the laboratory using sunflower plants was

concentrated in the roots. Rhizofiltration technology

has been tested in the field with U-contaminated water

at concentrations of 21—874 )g/L at a former U

processing facility in Ashtabula, OH. The pilot-scale

rhizofiltration system provided final treatment to the

site source water and reduced U concentration to <20

)g/L before discharge to the environment. System

performance was subsequently evaluated under

different flow rates permitting the development of

effectiveness estimates for the approach.

Research

Differences in Root Uptake of Radiocesium by 30

Plant Taxa

Broadley, M.R. and Willey, N.J.

Environmental Pollution v 97:1-2 p 11(5) 1997

The concentration of Cesium (Cs) was measured in the

shoots of 30 plant taxa after exposing the roots to 0.1

)g/g radiolabelled Cs soil for 6 hours. The maximum

accumulation differences were between Chenopodium

quinoa and Koeleria macrantha (20-fold in Cs

concentration and 100-fold in total Cs accumulated).

The lowest Cs concentrations occurred in slow growing

Gramineae and the highest in fast growing

Chenopodiaceae. If radiocesium uptake by the

Chenopodiaceae during chronic exposures shows

similar patterns to those reported here after acute
 Abstracts of Phytoremediation Resources Inorganic Contaminants

21

exposure, then the food contamination implications and

the potential for phytoremediation of radiocesium 

contaminated soils using plants in this family may be

worth investigating.

Enhanced Accumulation of Pb in Indian Mustard by

Soil-Applied Chelating Agents

Blaylock, M.J.; Salt, D.E.; Dushenkov, S.; Zakharova,

O.; Gussman, C.; Kapulnik, Y.; Ensley, B.D.; and

Raskin, I.

Environmental Science & Technology v 31 p 860(6)

1998

Phytoremediation is emerging as a potential costeffective solution for the remediation of contaminated

soils. Because contaminants such as lead (Pb) have

limited bioavailability in the soil, a means of

solubilizing Pb in the soil and facilitating its transport

to plant shoots is vital to the success of

phytoremediation. Indian mustard (Brassica juncea)

was used to demonstrate the capability of plants to

accumulate high tissue concentrations of Pb when

grown in Pb-contaminated soil. A concentration of

1.5% Pb in the shoots of B. juncea was obtained from

soils containing Pb (600 mg/kg) amended with

synthetic chelates such as EDTA. The accumulation of

Pb in the tissue 

corresponded to the concentration of Pb in the soil and

the concentration of EDTA added to the soil. The

accumulation of Cadmium, Copper, Nickel, and Zinc

from contaminated soil amended with EDTA and other

synthetic chelators was also demonstrated. The research

indicates that the accumulation of metals in the shoots

of B. juncea can be enhanced through the application of

synthetic chelates to the soil, facilitating high biomass

accumulation as well as metal uptake.

Evaluation of Tamarisk and Eucalyptus

Transpiration for the Application of

Phytoremediation

Tossell, R.W.; Binard, K.; Sangines-Uriarte, L.;

Rafferty, M.T.; and Morris, N.P.

Bioremediation and Phytoremediation: Chlorinated

and Recalcitrant Compounds

Battelle Press, Columbus, OH p 257(6) 1998

A greenhouse study was conducted to evaluate

phytoremediation using tamarisk and eucalyptus at a

site in East Palo Alto, CA, where the ground water was

contaminated with arsenic. The initial study assessed

whether the trees could tolerate arsenic and sodium

found in the ground water and soil. Over the course of

the study, tamarisk used significantly more water than

eucalyptus, but eucalyptus water use was substantially

higher than tamarisk when normalized to shoot mass.

Water use by both species was substantially lower for

trees exposed to high sodium treatments, but tamarisk

was less affected than eucalyptus.

Feasibility of Using Plants to Assist in the

Remediation of Heavy Metal Contamination at

J-Field, Aberdeen Proving Ground, Maryland. Final

Report

Jastrow, J.D.

29 pp November 1995

Interest in the development of in situ bioremediation

technologies has grown substantially over the last

decade. The purpose of this project was to investigate

the potential for using plants to remediate soils

contaminated with heavy metals. Phragmites australis,

one of the dominant species in the Toxic Burning Pits

(TBP) area and other contaminated sites within J-Field,

appears to be both tolerant of heavy metal contaminated

soil conditions and capable of producing large amounts

of biomass. Consequently, this project has concentrated

on characterizing heavy metal accumulation by

Phragmites australis growing in the TBP area relative

to soil concentrations and availabilities. This type of

information is necessary to determine the feasibility of

using this species to assist in the remediation of metal

contaminated soils at J-Field.

Lead-Contaminated Sediments Prove Susceptible to

Phytoremediation

Goldsmith, W.

Soil and Groundwater Cleanup p 15(3)

February/March 1998

[Also available at http://www.bioengineering.com

under the title Phytoremediation Potential for LeadContaminated River Sediments]
 Abstracts of Phytoremediation Resources Inorganic Contaminants

22

Most conventional technologies for removal or capping

of lead-contaminated river sediments are neither

technically nor economically practicable. Engineered 

wetlands for removal of lead from riverine sediments

appear to offer a sound approach to cleanup via

phytoextraction followed by harvesting. Plants have

been identified that grow in this type of environment

and possess a documented ability to take up lead into

leaves, roots, and stems. Recent research suggests that

phytoremediation conducted over a period of years can

offer significant benefits in sediment cleanup.

Lead Uptake and Effects on Seed Germination and

Plant Growth in a Pb Hyperaccumulator Brassica

pekinensis Rupr.

Xiong, Z.-T.

Bulletin of Environmental Contamination Toxicology v

60:2 p 285(7) February 1998

The ability of Brassica pekinensis Rupr. to

hyperaccumulate lead could make it effective for the

phytoremediation of contaminated soils. The effect of

various concentrations of lead on the germination of

seeds and growth of plants was investigated. Generally

germination and growth of roots and shoots

demonstrated dose-related inhibition. Bioaccumulation

of lead in root, stem, and leaf was related to lead

concentration in the growth medium. Roots

bioconcentrated lead to between 27 and 34 times the

concentration in growth medium. Stem and leaf

bioconcentration ranged from four to seven times and

two to three times, respectively. The shoot to root ratio

of lead was 0.9 for this plant species, which compares

well with other hyperaccumulators. High ratios allow

lead concentrated in shoots to be easily removed by

harvesting.

Metal Accumulation by Aquacultured Seedlings of

Indian Mustard

Salt, D.E.; Pickering, I.J.; Prince, R.C.; Gleba, D.;

Dushenkov, S.; Smith, R.D.; and Raskin, I. 

Environmental Science & Technology v 31 p 1636(9)

1997

Indian mustard (Brassica juncea (L.) Czern) seedlings

grown in aerated water were able to accumulate various

metals from contaminated water over a range of

environmentally relevant metal concentrations.

Seedlings concentrated the divalent cations Lead(II),

Strontium(II), Cadmium(II), and Nickel(II) 500-2000

times and concentrated monovalent Cesium(I) and

hexavalent Chromium(IV) 100-250 times from

contaminated water containing the competing ions Ca,

Mg, K, SO4, and NO3. At the lowest Cadmium (Cd)

concentration studied, Cd levels were reduced to below

10 ppb ()g/L). In the absence of competing ions, Cd

accumulation in seedlings increased 47-fold. This

suggests that a better understanding of the biological

processes governing uptake and accumulation of Cd by

seedlings should allow the application of modern

genetic engineering techniques to improve their

selectivity and capacity for Cd removal from waters

containing high levels of competing ions. As a first step

in this process, we have started to define the tissue and

cellular localization of Cd, its accumulation rates and

possible uptake mechanisms, and the role of

intracellular chelates in Cd detoxification. Intracellular

Cd accumulation in seedlings was mediated by

saturable transport system(s) and inhibited

competitively in shoots and non-competitively in roots

by Ca2+, Zn2+, and Mn2+. Phytochelatins, the Cd-binding

peptides known to be involved in Cd resistance in

mature plants, also accumulated in B. juncea seedlings

exposed to Cd. Our results suggest that the use of

aquacultured seedlings of B. juncea could provide a

novel approach to the treatment of various metalcontaminated waste streams.

Phytoextraction of Cadmium and Zinc from a

Contaminated Soil

Ebbs, S.D.; Lasat, M.M.; Brady, D.J.; Cornish, J.;

Gordon, R.; and Kochian, L.V.

Journal of Environmental Quality v 26:5 p 1424(7)

September-October 97

The phytoextraction ability of Brassica juncea, B.

napus, and B. rapa toward cadmium (Cd) and zinc

(Zn) in a contaminated soil was determined and

compared to that exhibited by Thlaspi caerulescens,

Agrostis capillaris, and Festuca rubra. Results showed

that T. caerulescens achieved shoot Cd concentrations

approximately ten times as great as those of the three

Brassica species, while shoot Zn concentrations in T.

caerulescens were approximately 2.5 times as great.
 Abstracts of Phytoremediation Resources Inorganic Contaminants

23

However, due to the significantly greater biomass

produced by the Brassica species, this species was more 

effective in removing Zn and equally effective in

removing Cd as T. caerulescens.

Phytoextraction of Zinc by Oat (Avena sativa),

Barley (Hordeum vulgare), and Indian Mustard

(Brassica juncea)

Ebbs, S.D.; and Kochian, L.V.

Environmental Science & Technology v 32:6 802(5)

1998

The success of phytoremediation depends on the

selection of plant species and soil amendments that

maximize contaminant removal. Indian mustard

(Brassica juncea) has been shown to be effective in

phytoextracting Zn, particularly after the synthetic

chelate EDTA has been applied to the soil. However,

the effectiveness of grass species for phytoremediation

has not been addressed in great detail. A hydroponic

screening of 22 grass species indicated that oat (Avena

sativa) and barley (Hordeum vulgare) tolerated the

high copper, cadmium, and zinc concentrations present

in the solution and also accumulated elevated

concentrations of these metals in the plant shoots. A

hydroponic experiment comparing these two grasses to

Indian mustard indicated that, although shoot Zn

concentrations were greater for Indian mustard, the

grasses were considerably more tolerant. The results of

this experiment suggest that barley has a

phytoremediation potential equal to, if not greater than,

that for B. juncea.

Phytoextraction: the Use of Plants to Remove Heavy

Metals from Soils

Kumar, P. B. A. N.; Dushenkov, V.; Motto, H.; and

Raskin, I.

Environmental Science & Technology v 29:5 p 1232(7)

May 1995

The process of phytoextraction, the use of plants to

remove heavy metals from soils, generally requires the

translocation of heavy metals to the easily harvestable

shoots. Several cultivars of Indian mustard (Brassica

juncea) were investigated for their ability to efficiently

accumulate lead and other heavy metals. The Brassica

species included B. nigra, B. oleracea, B. campestris,

B. carinata, B. juncea, and B. napus. Results indicate

that B. juncea and B. nigra had the highest

metal-accumulating ability among the species tested.

Shoot growth was only slightly affected by exposure to

lead over the concentration range tested. For the other

metals examined, chromium had the highest

phytoextraction coefficient, followed by cadmium,

nickel, zinc, and copper.

Phytofiltration of Hazardous Cadmium, Chromium,

Lead and Zinc Ions by Biomass of Medicago sativa

(Alfalfa)

Gardea-Torresdey, J.L.; Gonzalez, J.H.; Tiemann, K.J.;

Rodriguez, O.; and Gamez, G. 

Journal of Hazardous Materials v 57:1-3 p 29(11)

1998

Previous laboratory batch experiments of Medicago

sativa (Alfalfa) indicated that the African shoots

population had an appreciable ability to bind copper(II)

and nickel(II) ions from aqueous solution. Batch

laboratory pH profile, time dependency, and capacity

experiments were performed to determine the binding

ability of the African shoots for cadmium(II),

chromium(III), chromium(VI), lead(II), and zinc(II).

Batch pH profile experiments indicate that the optimum

pH for metal binding is approximately 5.0. Time

dependency experiments demonstrate that metal

binding to the African alfalfa shoots occurred within 5

minutes. Binding capacity experiments revealed the

following amounts of metal ions bound per gram of

biomass: 7.1 mg Cd(II), 7.7 mg Cr(III), 43 mg Pb(II),

4.9 mg Zn(II), and 0 mg Cr(VI). The results from these

studies will be useful in the use of phytofiltration to

remove and recover heavy metal ions from aqueous

solution.

Phytoremediation of a Radiocesium-Contaminated

Soil: Evaluation of Cesium137 Bioaccumulation in the

Shoots of Three Plant Species

Lasat, M.M.; Fuhrmann, M.; Ebbs, S.D.; Cornish, J.E.;

and Kochian, L.V.

Journal of Environmental Quality v 27:1 p 165(5)

January-February 1998
 Abstracts of Phytoremediation Resources Inorganic Contaminants

24

At Brookhaven National Laboratory's Hazardous Waste

Management Facilities, the potential for cesium-137

(

137Cs) extraction from contaminated soil by three plant

species was studied. In addition, the effect of applying 

ammonium nitrate to contaminated soil on 137Cs

extraction was evaluated. The plants used were Indian

mustard, red root pigweed, and tepary bean. Results

show that red root pigweed concentrated the highest

level of 137Cs in shoots, followed by Indian mustard and

tepary bean. Red root pigweed also produced

significantly more shoot biomass than the other two

species. Ultimately, red root pigweed removed 30- to

60-fold more 137Cs from the soil than either of the other

two species. For red root pigweed and tepary bean, the

addition of ammonium nitrate produced only a slight

increase in the level of 137Cs in shoots.

Phytoremediation of Lead-Contaminated Soils: Role

of Synthetic Chelates in Lead Phytoextraction

Huang, J.W.; Chen, J.; Berti, W.R.; and Cunningham,

S.D.

Environmental Science & Technology v 31:3 p 800(6)

March 1997

Studies have shown that lead (Pb) is accumulated in the

roots of plants if Pb is bioavailable in the growth

media. However, Pb bioavailability is limited. The

relative efficiencies of selected synthetic chelates in

enhancing Pb phytoextraction were compared. Corn,

pea, goldenrod, sunflower, and ragweed were used, in

combination with the chelates, EDTA, HEDTA, DTPA,

EGTA, and EDDHA. Results show that Pb in soil

solution increased linearly with increasing levels of

HEDTA added to a Pb-contaminated soil. In all plant

species tested, there was a surge in shoot Pb

concentrations in response to the application of

HEDTA, with the highest shoot Pb concentrations

found in pea, followed by corn and sunflower. When

experiments were continued with pea and corn plants,

Pb accumulation was highest in the presence of EDTA,

followed in decreasing order by HEDTA, DTPA,

EGTA, and EDDHA. The rank in the efficiency in

enhancing total Pb accumulation in shoots was the

same as that found in enhancing soil Pb desorption.

Phytoremediation of Selenium Laden Soils: A New

Technology

Banuelos, G.S.; Ajwa, H.A.; Terry, N.; and Zayed, A.

Journal of Soil and Water Conservation v 52:6 p

426(5) November-December 1997

Selenium (Se) is naturally present in many soils around

the U.S. High concentrations of Se may exert toxic

impacts on plants and animals. The performance of

several plant species (including canola, Indian mustard,

birdsfoot trefoil, tall fescue, and kenaf) in

phytoremediation projects aimed at reducing soil Se

levels to below toxic concentrations are reviewed. The

best plants for these types of projects include Brassica

and Astragalus species.

Phytoremediation of Uranium-Contaminated Soils:

Role of Organic Acids in Triggering Uranium

Hyperaccumulation in Plants

Huang, J.W.; Blaylock, M.J.; Kapulnik, Y.; and Ensley,

B.D.

Environmental Science & Technology v 32:7 p 2004(5)

1998

Uranium (U) phytoextraction, the use of plants to

extract U from contaminated soils, is an emerging

technology. In this research, the effects of various soil

amendments on U desorption from soil to soil solution

were investigated, physiological characteristics of U

uptake and accumulation in plants were studied, and

techniques to trigger U hyperaccumulation in plants

were developed. Of the organic acids (acetic acid, citric

acid, and malic acid) tested, citric acid was the most

effective in enhancing U desorption and subsequent

accumulation in plants. Shoot U concentrations of

Brassica juncea and Brassica chinensis grown in a Ucontaminated soil (total soil U, 750 mg/kg) increased 

from less than 5 mg/kg to more than 5000 mg/kg in

citric acid-treated soils. These results suggest that U

phytoextraction may provide an environmentally

friendly alternative for the cleanup of U-contaminated

soils.
 Abstracts of Phytoremediation Resources Inorganic Contaminants

25

Potential for Phytoextraction of 137CS from a

Contaminated Soil

Lasat, M.M.; Norvell, W.A.; and Kochian, L.V.

Agricultural Research Service, Beltsville, MD February

1998

Cesium-137 (137Cs) is a long-lived by-product of

nuclear fission. Phytoremediation of

radiocesium-contaminated sites is impeded by the 

marked capacity of soils to tightly adsorb 137Cs and

limit its availability for plant uptake. Bioavailability

testing of a number of soil extractants from an aged

contaminated soil obtained from Brookhaven National

Laboratory demonstrated that ammonium salts released

a large portion of the radiocesium trapped in the soil.

This same amendment greatly stimulated the

bioaccumulation of 137Cs in plant shoots. Use of the best

performing plant species from a species selection trial

(cabbage), in conjunction with amending the soil with

ammonium nitrate, resulted in dramatic improvements

in the accumulation of 137Cs in plant shoots compared

with the results of many previous published studies (10

to 300-fold improvement). These findings indicate that

the phytoremediation of 137Cs contaminated soils is a

very promising cleanup technology. 

Potential Remediation of 137Cs and 90Sr

Contaminated Soil by Accumulation in Alamo

Switchgrass

Entry, J.A. and Watrud, L.S.

Water, Air, and Soil Pollution v 104:3-4 p 339(14) June

1998

Alamo switchgrass was evaluated on its ability to

remove cesium-137 and strontium-90 from

contaminated soil. Results show that the above-ground

biomass of the plants accumulated 36% of the

cesium-137 and 44% of the strontium-90 in the growth

medium. However, the accumulated concentrations in

the plants declined after two harvests. For both

radionuclides, the duration of exposure correlated

curvilinearly with accumulation by the plants. As the

concentration of both radionuclides increased in the

growth medium, total seedling accumulation and

concentration of radioisotopes in plant tissue also

increased curvilinearly. The overall findings revealed

that Alamo switchgrass may be a good candidate

species for remediating radionuclide-contaminated

soils.

Rhizofiltration: the Use of Plants to Remove Heavy

Metals from Aqueous Streams

Dushenkov, V.; Kumar, P. B. A. N.; Motto, H.; and

Raskin, I.

Environmental Science & Technology v 29:5 p 1239(7)

May 1995

Rhizofiltration is the use of plants to remove heavy

metals from aqueous streams. Hydroponically grown

roots of Indian mustard (Brassica juncea) were

investigated for their ability to remove lead, cadmium,

copper, chromium, nickel, and zinc from solution. The

rate of lead removal depended on the initial

concentration in solution and showed a monotonic

decline with time. Since the magnitude of lead removal

was proportional to the root weight, much faster

removal rates were achieved when a larger root mass

was used. Significant removal rates were also seen for

the other metals. Only live roots were able to remove

metals from solution.

The Role of EDTA in Pb Transport and

Accumulation by Indian Mustard

Vassil, A.D.; Kapulnik, Y.; Raskin, I.; and Salt, D. 

Plant Physiology v 117 p 447(7) 1998

Indian mustard (Brassica Juncea) plants exposed to

lead (Pb) and EDTA in hydroponic solution were able

to accumulate up to 55 mmol/kg Pb in dry shoot tissue

(1.1%[w/w]). This represents a 75-fold concentration of

Pb in shoot tissue over that in solution. A threshold

concentration of EDTA (0.25 mmol) was found to be

required to stimulate this dramatic accumulation of

both Pb and EDTA in shoots. The majority of Pb in

these plants is transported in coordination with EDTA.

Exposure of Indian mustard to high concentrations of

Pb and EDTA caused reductions in both the

transpiration rate and the shoot water content. The

onset of these symptoms was correlated with the

presence of free protonated EDTA (H-EDTA) in the

hydroponic solution, suggesting that free H-EDTA is

more phytotoxic than Pb-EDTA. These studies clearly

demonstrate that coordination of Pb transport by EDTA
 Abstracts of Phytoremediation Resources Inorganic Contaminants

26

enhances the mobility within plants of this otherwise

insoluble metal ion, allowing plants to accumulate high

concentrations of Pb in shoots. The finding that both HEDTA and Pb-EDTA are mobile within plants also has 

important implications for the use of metal chelates in

plant nutritional research.

A Search for Lead Hyperaccumulating Plants in the

Laboratory

Ghosh, S.; and Rhyne, C.

Agriculture and Plant Science Meeting, Mississippi

State University, 1997

The research objective is to identify plant species

capable of sustained healthy growth in elevated lead

concentrations and to evaluate their effectiveness in

accumulating high levels of lead in various parts of the

plants. A modified hydroponic growing system was

used to suspend plants in aqueous solutions of either

Hoagland's nutrient medium or varying concentrations

of Pb(NO3)2 in the laboratory. Thirty-three different

plant species were tested and grouped into five

categories based on their growth potential and lead

uptake. Two plant species, Ipomoea lacunosa and

Sesbania exaltata, appear to have significant potential

as lead hyperaccumulators. After the desired exposure

period, plants were harvested and separated into leaves,

stems and roots to analyze and locate the accumulation

of lead in different plant parts. Morphological

characteristics (height and dry weight) of the plants

were also observed. 

Selenium Accumulation by Brassica Napus Grown in

Se-laden Soil from Different Depths of Kesterson

Reservoir

Banuelos, G.S.; Ajwa, H.A.; Wu, L.; and Zambrzuski,

S.M.

Agricultural Research Service, Beltsville, MD August

1997

Elevated levels of selenium (Se) have been measured in

sediment at Kesterson Reservoir and contributed to the

death and deformities observed in waterfowl

frequenting this site. As part of a remediation strategy

to lower levels of soil Se, canola was planted in

Se-contaminated sediment collected from the Reservoir,

as well as on-site. Canola lowered Se concentrations

more effectively under greenhouse conditions than in

the field. The study clearly shows that extrapolating

results from greenhouse to field conditions should be

done with caution. Using canola to lower Se levels at

Kesterson Reservoir will be a long-term management

strategy under field conditions.

Test Plan for the Phytoremediation Studies of

Lead-Contaminated Soil from the Sunflower Army

Ammunition Plant, Desoto, Kansas. Vol. 1 and Vol. 2

Behel, D.; Kelly, D.; Pier, P.; Rogers, B.; and Sikora,

F.

233 pp (v 1), 291 pp (v 2) October 1996

NTIS Document Number: ADA342667 (vol. 1) 

ADA342668 (vol. 2) 

This document provides a test plan for studying and

improving techniques for remediating leadcontaminated soils using phytoremediation. It also

discusses a study to examine the uptake of lead by

plants in contaminated soil. 

Toxicity of Zinc and Copper to Brassica Species:

Implications for Phytoremediation

Ebbs, S.D. and Kochian, L.V.

Journal of Environmental Quality v 26:3 p 776(6) 1997

The toxicity of Zn and Cu in three species from the

genus Brassica was examined to determine if these

plants showed sufficient tolerance and metal

accumulation to phytoremediate a site contaminated

with these two heavy metals. Hydroponically grown 12

day-old plants of Brassica juncea, B. rapa, and B.

napus were grown for an additional 14 days in the

presence of either elevated Zn (6.5 mg/L), Cu (0.32

mg/L), or Zn plus Cu to quantify the toxic effects of

these metals on several different growth parameters.

With few exceptions, both root and shoot dry weight for

all three species decreased significantly in the presence

of heavy metals. In terms of heavy metal removal, the

Brassica species were more effective at removing Zn

from the nutrient solution than Cu. The extent of Zn

and Cu removal was reduced when both metals were

present as compared to the single heavy metal
 Abstracts of Phytoremediation Resources Internet Resources

27

treatments. The implications of these results for

phytoremediation are discussed.

Toxic Mercury Reduction and Remediation Using

Transgenic Plants with a Modified Bacterial Gene

Rugh, C.L.; Gragson, G.M.; Meagher, R.B.; and

Merkle, S.A. 

University of Georgia, Athens, GA

HortScience v 33:4 p 618(4) July 1998

The objective of this paper is to give a brief overview of

the concepts and progress of microbial- and plantassisted pollution remediation research. A summary of

efforts to genetically engineer plants for mercury

reduction and detoxification, as well as considerations

for future research toward this goal, will be presented.

Zinc and Cadmium Accumulation in the

Hyperaccumulator Thlaspi Caerulescens in Response

to Limestone and Compost Applications to a Heavy

Metal Contaminated Site in Palmerton,

Pennsylvania

Li, Y.M.; Chaney, R.L.; Kershner, B.A.; Chen, K.Y.;

Angle, J.S.; and Baker, A.J.

Agricultural Research Service, Beltsville, MD

September 1997

Research is being conducted to develop a new

technology using plants to remove Zn and Cd from

contaminated soils which require remediation. Thlaspi

caerulescens is a perennial herb which accumulates Zn

(>3%) from soils to much higher foliar levels than

economic crops. At the Palmerton, PA site, soil metal

concentrations are very high and the soils are

non-calcareous. It is likely that Thlaspi may suffer Zn

phytotoxicity. Studies were conducted to characterize

the long term effect of limestone and compost

applications on plant biomass and Zn and Cd

accumulation. In addition, the uptake of metals by

hyperaccumulator T. caerulescens was compared to

uptake by a local metal-tolerant species, Merlin red

fescue. In this paper, we report that compost treatment

reduced metal phytotoxicity. We have also determined

that higher soil pH and organic matter were the

important factors attributing to the large shoot biomass

accumulation for Thlaspi. 

Publications Containing Multiple Papers

Metal-Contaminated Soils: In Situ Inactivation and

Phytorestoration 

Vangronsveld, J. and Cunningham, S. (eds.) 

R.G. Landes, Austin, TX

Bioremediation of Inorganics, Vol. 3

Hinchee, R.E.; Means, J.L.; and Burris, D.R. (eds.)

Battelle Press, Columbus, OH 184 pp 1995

Plants That Hyperaccumulate Metals: Their Role in

Phytoremediation, Microbiology, Archaeology,

Mineral Exploration, and Phytomining 

Brooks, R. R. (ed.)

CAB International, New York

Internet Resources

Advanced Applied Technology Demonstration

Facility (AATDF)

http://www.ruf.rice.edu/~aatdf

AATDF is a research facility funded by the Department

of Defense, Army Corps of Engineers, Waterways

Experiment Station (WES) through the Energy and

Environmental Systems Institute at Rice University.

One of its long-term projects involves evaluating and

recommending innovative treatment technologies in

support of faster and cheaper remediation.

Air Force Center for Environmental Excellence

(AFCEE)

http://www.afcee.brooks.af.mil

The Air Force Center for Environmental Excellence

provides a complete range of environmental,

architectural, and landscape design, planning and

construction management services and products.

Environmental restoration is one of its several business

lines, and its services include: studies and

investigations, project design, cleanup, long-term

operation/monitoring, program support, and new

restoration technology research. It was formed in 1991.
 Abstracts of Phytoremediation Resources Internet Resources

28

Alternative Treatment Technology Information

Center (ATTIC)

http://www.epa.gov/attic

The EPA Office of Research and Development (ORD)

Alternative Treatment Technology Information Center

(ATTIC) is a comprehensive computer database system

providing up-to-date information on innovative

treatment technologies. ATTIC provides access to

several independent databases as well as a mechanism

for retrieving full-text documents of key literature. The

system provides information to make effective decisions

on hazardous waste clean-up alternatives. 

CLU-IN: Hazardous Waste Clean-Up Information

http://clu-in.org

The Hazardous Waste Clean-Up Information (CLU-IN)

Web Site provides information about innovative

treatment technologies to the hazardous waste

remediation community. It describes programs,

organizations, publications, and other tools for federal

and state personnel, consulting engineers, technology

developers and vendors, remediation contractors,

researchers, community groups, and individual citizens.

The site was developed by the U.S. EPA but is intended

as a forum for all waste remediation stakeholders.

Environmental Security Technology Certification

Program (ESTCP)

http://www.estcp.org

ESTCP's goal is to demonstrate and validate promising,

innovative technologies that et the Department of

Defense's (DoD's) most urgent environmental needs.

These technologies provide a return on investment

through cost savings and improved efficiency. The

current cost of environmental remediation and

regulatory compliance in the Department is significant.

Innovative technology offers the opportunity to reduce

costs and environmental risks. ESTCP's strategy is to

select lab-proven technologies with broad DoD and

market application. These projects are aggressively

moved to the field for rigorous trials that document

their cost, performance, and market potential.

Successful demonstration leads to acceptance of

innovative technologies by DoD end-users and the

regulatory community. 

Federal Remediation Technologies Roundtable

http://www.frtr.gov

The mission of the Roundtable is to exchange

information and provide a forum for joint activity

regarding the development and demonstration of 

innovative technologies for hazardous waste site

remediation. The exchange synthesizes the technical

knowledge that Federal Agencies have compiled and

provides a more comprehensive record of performance

and cost. Members include major developers and users

of these technologies: Department of Defense (U.S.

Army, U.S. Army Corps of Engineers, U.S. Navy, U.S.

Air Force), U.S. Department of Energy, U.S.

Department of the Interior, and the U.S. Environmental

Protection Agency.

GNET: The Global Network of Environment and

Technology

http://www.gnet.org

GNET® is an on-line global information center for

environmental technology. The site contains an

interactive environmental technology database

(TechKnow) that houses information on

phytoremediation and over 1,500 other technologies. 

Great Plains/Rocky Mountain Hazardous Substance

Research Center

http://www.engg.ksu.edu/HSRC

Kansas State University leads a fourteen-institution

consortium for the Great Plains/ Rocky Mountain

Hazardous Substance Research Center. The other

member institutions are Lincoln, Haskell Indian

Nations, Colorado State, Montana State, South Dakota

State, and Utah State Universities, along with the

universities of Iowa, Northern Iowa, Missouri,

Montana, Nebraska, Utah, and Wyoming. The center

was established in 1989 to conduct research pertaining

to hazardous substances produced through agriculture,

forestry, mining, mineral processing, and other
 Abstracts of Phytoremediation Resources Internet Resources

29

activities of local interest. It serves Federal Regions 7

and 8. Specific research projects focus on soil and water

contaminated by heavy metals from mining wastes and

other industrial activities, soil and ground water

contaminated by organic chemicals, wood preservatives

that contaminate ground water, pesticides identified as

hazardous substances, improved technologies and

methods for characterizing and analyzing contaminated

soil, and waste-minimization and pollution-prevention

methods and technologies. The tables of contents,

abstracts, and selected papers of the Proceedings of the

Annual Conference on Hazardous Waste Research

beginning with the Ninth Annual Conference (1994)

onward may also be viewed at the Web site.

Ground Water Remediation Technologies Analysis

Center (GWRTAC)

http://www.gwrtac.org

The Ground Water Remediation Technologies Analysis

Center (GWRTAC) is a focal point for the collection

and analysis of information on ground water

remediation. The members of GWRTAC compile,

analyze, and disseminate information on innovative

ground water remediation technologies. Technical

teams are selectively chosen from Concurrent

Technologies Corporation (CTC), the University of

Pittsburgh, and other supporting institutions. 

Innovative Treatment Remediation Demonstration

(ITRD) 

http://www.em.doe.gov/itrd

The Innovative Treatment Remediation Demonstration

(ITRD) Program is funded by the DOE Office of

Environmental Restoration (EM-40) to help accelerate

the adoption and implementation of new and innovative

remediation technologies. Developed as a

Public-Private Partnership program with Clean Sites,

Inc., and the Environmental Protection Agency's (EPA)

Technology Innovation Office (TIO) and coordinated 

by Sandia National Laboratories, the ITRD Program

attempts to reduce many of the classic barriers to the

use of new technologies by involving government,

industry, and regulatory agencies in the assessment,

implementation, and validation of innovative

technologies. 

Interstate Technology and Regulatory Cooperation

Working Group (ITRC)

http://www.sso.org/ecos/itrc

The Interstate Technology and Regulatory Cooperation

Working Group (ITRC) was established in December,

1994 by the Develop On-Site Innovative Technology

Committee, referred to as the DOIT Coordinating

Group of the Western Governors Association. The

Mission of the ITRC is to facilitate cooperation among

states in the common effort to test, demonstrate,

evaluate, verify and deploy innovative environmental

technology, particularly technology related to waste

management, site characterization and site cleanup.

Regulators from 24 states are collaborating with

representatives from federal agencies, industry, and

stakeholder groups to raise the comfort level of

environmental decision makers about using new

technologies. By pooling their experience and

knowledge in permitting innovative technologies and

by publishing and distributing their work products,

ITRC is making it easier for state regulatory agencies to

approve new technologies.

PHYTONET - Phytoremediation Electronic

Newsgroup Network

http://www.dsa.unipr.it/phytonet

The Phytonet Newsgroup was developed to allow easy

worldwide communications between scientists who

work on problems related with Phytoremediation and

Application of Plant Systems to Environmental

Control. The Phytoremediation Electronic Network,

moderated by Nelson Marmiroli, is operated by the

Department of Environmental Sciences, University of

Parma, Italy. 

Remediation Technologies Development Forum

(RTDF) 

Phytoremediation of Organics Action Team

http://www.rtdf.org/public/phyto
 Abstracts of Phytoremediation Resources Internet Resources

30

The Phytoremediation of Organics Action Team was

established in 1997, as one of seven Action Teams

under the Remediation Technologies Development

Forum (RTDF). The Phytoremediation of Organics

Action Team includes representatives from industry

and government who share an interest in further

developing and evaluating the of use of plants and trees

to remediate contaminated soil and water. 

Strategic Environmental Research and Development

Program (SERDP)

http://www.serdp.gov

The Strategic Environmental Research and

Development Program is the Department of Defense’s

(DoD) corporate environmental R&D program, planned

and executed in full partnership with the Department of

Energy (DOE) and the Environmental Protection

Agency (EPA), with participation by numerous other

federal and non-federal organizations. Within its broad

areas of interest, the Program focuses on Cleanup,

Compliance, Conservation, and Pollution Prevention

technologies. 

U.S. Army Corps of Engineers Phytoremediation

Research

http://www.wes.army.mil/EL/phyto

The U.S. Army Corps of Engineers Innovative

Technology Program mission is to inform, encourage,

promote, and support the development and use of

innovative technology for environmental investigation

and remediation. Its Phytoremediation Research site is

part of the Waterways Experiment Station

Environmental Laboratory Web site.

U.S. Army Environmental Center (USAEC)

http://aec-www.apgea.army.mil:8080

The USAEC Technology link provides access to

descriptions of innovative restoration technology

demonstrations conducted at numerous Army

installations.

U.S. Department of Agriculture (USDA)

http://www.usda.gov

In addition to supporting research to improve

agricultural production, the USDA also supports

research concerning remediation of soil and ground

water contaminated with pesticides, herbicides, and

fertilizers. The Current Research Information System

(CRIS) database is a documentation and reporting

system for ongoing and recently completed research

projects. The Technology Transfer Automated Retrieval

System (TEKTRAN) provides abstracts of research

results from the UDSA’s Agricultural Research Service

that will be published as articles or documents. 

CRIS: http://cristel.nal.usda.gov:8080

TEKTRAN: http://www.nal.usda.gov/ttic/tektran