EPA/540/A5-91/001

September 1991

Biological Treatment of Wood Preserving Site

Groundwater by BioTrol, Inc.

Applications Analysis Report

Risk Reduction Engineering Laboratory

Office of Research and Development

U.S. Environmental Protection Agency

Cincinnati, OH 45268

@ Printed on Recycled Paper
Notice

The information in this document has been funded by theU.S. Environmental Protection.

Agency under the auspices of the Superfund Innovative Technology Evaluation (SlTE)

Program under Contract No. 68-03-3485 to Science Applications International Corporation.

It has been subjected to the Agency’s peer and administrative review, and it has been

approved for publication as an EPA document. Mention of trade names or commercial

products does not constitute an endorsement or recommendation for use.
Foreword

The Superfund Innovative Technology Evaluation (SITE) Program was authorized in

the 1986 Superfund Amendments. The Program is a joint effort between EPA’s Office of

Research and Development and Office of Solid Waste and Emergency Response. The

purpose of the program is to assist the development of hazardous waste treatment technologies necessary to implement new cleanup standards which require greater reliance on

permanent remedies. This is accomplished through technology demonstrations designed to

provide engineering and cost data on selected technologies.

This project consisted of a demonstration of BioTrol, Inc.‘s fixed-film, amended

biological treatment process and an analysis of the effectiveness of the system. The study was

carried out at the MacGillis and Gibbs Company site in New Brighton,MN,a site where wood

preserving operations have been carried out over several decades using each of the traditional

preserving chemical systems: first creosote, later pentachlorophenol, and most recently,

chromated copper arsenate. In 1984 the site was added to the National Priorities List as one

where soil and groundwater were contaminated with hazardous chemicals. The goals of the

study, summarized in this Applications Analysis Report and described in more detail in the

companion Technology Evaluation Report, were to evaluate the technical effectiveness and

economics of a specific biological treatment process for the elimination of pentachloropheno1 (and polynuclear aromatic hydrocarbons found in creosote) from groundwater and to

establish the potential applicability of the process to other wastes and/or other Superfund and

hazardous waste sites.

Additional copies of this report may be obtained at no charge from EPA’s Center for

Environmental Research Information, 26 West Martin Luther Ring Drive, Cincinnati, OH

45268, using the EPA document number found on the report’s front cover. Once this supply

is exhausted, copies can be purchased from the National Technical Information Service,

Ravensworth Bldg., Springfield, VA, 22161, 703-487-4650. Reference copies wilI be

available at EPA libraries in their Hazardous Waste Collection. You can also call the SITE

Clearinghouse hotline at l-800-424-9346 or 202-382-3000 in Washington, DC, to inquire

about the availability of other reports.

E. Timothy Oppelt, Director

Risk Reduction Engineering Laboratory

. . . III
Abstract

This document is an evaluation of the BioTrol, Inc., Aqueous Treatment System

(BATS), a fixed-film, aerobic biological treatment process for contaminated groundwaters

and other wastewaters.

This report summarizes and analyzes the results of the Superfund Innovative Technology Evaluation (SITE) Program’s six week demonstration at the MacGillis and Gibbs

Company wood preserving site in New Brighton, MN. Other pertinent data from BioTrol

investigations are included to support the demonstration results. Conclusions were reached

concerning the technological effectiveness and economics of the process and its suitability

for use at other sites.

During the SITE demonstration, operations and sampling and analysis were carefully

monitored to establish a database against which the vendor’s claims for the technology could

be evaluated reliably. These claims were that the BATS could achieve 90% removal of

pentachlorophenol (PCP) and polynuclear aromatic hydrocarbons (PAHs) and that penta

removal was by mineralization.

The conclusions from the pilot scale demonstration study and other available data are:

(1) the fixed film aerobic process is capable of degrading pentachlorophenol (PCP) and other

organic pollutants to more than 95% removal; (2) effluent concentrations of PCP well below

1 mg/L are attainable, if necessary by increasing the retention time, i.e., decreasing the

throughput rate; (3) removal of PCP is largely by mineralization to carbon dioxide, water and

saltbasedonchlorideyields; (4) acute toxicity of the PCP-contaminated groundwater, at least

to minnows and water fleas, is eliminated, (5) operating cost for labor, chemicals, and energy

range from $3.45/1000 gal at 5 gpm to $2.43/1000 gal at 30 gpm and total capital and

operating cost can be as low as $2.94/1000 gallons, and (6) other factors, including ambient

temperature and the presence of other contaminants in the feedwater, may affect total cost and

operating efficiency.

iv
Contents

V
vi
Figures

A-l

A-2

A-3

A-4

B-l

B-2

C-l

C-2

C-3

D-l

D-2

vii
Tables

. . . VIII
BATS

BOD

BTEX

CERCLA

cfm

COD

EMSL

GC/MS

gpd

gpm

HPLC

HSWA

kwh

LC(50)

Mgd

mg/kg

ng/kg

ng/L

NPL

O/G

ORD

OSHA

OSWER

PAHs

PCP

PEL

POTW

ppb

ppm

psi

PVC

QA/QC

RCRA

RI/FS

SAIC

SARA

SITE

TCPs

TOC

TSS

Abbreviations and Symbols

BioTrol Aqueous Waste Treatment System

biochemical oxygen demand (mg oxygen/liter)

benzene, toluene, ethyl benzene, and xylenes

Comprehensive Environmental Response, Compensation, and Liability Act of 1980

cubic feet per minute

chemical oxygen demand (mg oxygen/liter)

Environmental Monitoring Systems Laboratory

gas chromatograph/mass spectrometer

gallons per day

gallons per minute

high pressure liquid chromatogmph

Hazardous and Solid Waste Amendments to RCRA - 1984

kilowatt-hour

lethal concentration to 50% of a test species population

million gallons per day

milligrams per liter

nanograms per kilogram

nanograms per liter

National Priorities List

oilandgrease

Office of Research and Development

Occupational Safety and Health Administration or Act

Office of Solid Waste and Emergency Response

polynuclear aromatic hydrocarbons

pentachlorophenol

Permissible Exposure Limit

publicly owned treatment works

parts per billion

parts per million

pounds per square inch

polyvinyl chloride

quality assurance/quality control

Resource Conservation and Recovery Act of 1976

Remedial Investigation/Feasibility Study

Risk Reduction Engineering Laboratory

Science Applications International Corporation

Superfund Amendments and Reauthorization Act of 1986

Superfund Innovative Technology Evaluation

tetrachlorophenols

total organic carbon (mg carbon/liter)

total suspended solids (mg solids/liter)

ix
Conversion Factors

Area:

Flow Rate:

Length:

Mass:

Volume:

English (US)

1 ft2

1 in2

1 gal/min

1 gal/min

1 Mgal/d

1 Mgal/d

1 Mgal/d

1 ft

1 in.

1 yd

1 lb

1 lb

1 ft’

1 ft3

1 gal

1 gal

x

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Factor

9.2903 x 102

6.4516

6.3090 x lO-5

6.3090 x 102

43.8126

3.7854 x 103

4.3813 x 102

0.3048

2.54

0.9144

4.5359 x 102

0.4536

28.3168

2.8317 x 102

3.7854

3.7854 x 1O-3

ft = foot, ft2 = square foot, ft3 = cubic foot

in. = inch, in2 = square inch

yd = yard

lb = pound

gal = gallon

gal/min (or gpm) = gallons per minute

Mgal/d (or MGD) = million gallons per day

m = meter, m2 = square meter, m3 = cubic meter

cm = centimeter, cm2 = square centimeter

L = liter

kg = kilogram

m3/s = cubic meters per second

L/s = liters/sec

m3/d = cubic meters per day

= Metric

cm2

= cm2

= m3/s

=L/s

= L/s

= m3/d

= m3/s

=m

=cm

=m

= g

= kg

= L

=m3

= L

=m3

X
Acknowledgments

This report was directed and coordinated by Mary K. Stinson, EPA SITE Project

Manager in the Risk Reduction Engineering Laboratory--Cincinnati, Ohio. It was prepared

for EPA’s Super-fund Innovative Technology Evaluation (SITE) Program by Herbert S.

Skovronek and William Hahn of Science Applications International Corporation for theU.S.

Environmental Protection Agency under Contract No. 68-03-3255.

The cooperation and participation of Thomas J. Chresand and supporting staff of

BioTrol, Inc. throughout the course of the project and in review of this report are gratefully

acknowledged, as is the assistance of A.J. Bamby of MacGillis and Gibbs. Mark Lahtinen of

the Minnesota Pollution Control Agency (MPCA) and Rhonda McBride, Linda Kern, and

Darryl Owens, the Remedial Project Managers of USEPA’s Region V provided invaluable

assistance and guidance in initiating the project and in interpreting and responding to

regulatory needs of the project. Ronald Lewis and Gordon Evans of USEPA’s Risk

Reduction Engineering Laboratory and Linda D. Fiedler of the Technology Innovation

Office of OSWER provided invaluable reviews of the draft report Finally, the project could

not have been carried out without the tireless efforts of the many SAIC and Radian field and

laboratory personnel.

xi
Section 1

Executive Summary

Introduction

BioTrol, Inc.‘s Aqueous Treatment System (BATS) has

been used to treat a pentachlorophenol-contaminated groundwater stream at a site on the Superfund National Priorities

List. Operational and cost data were collected for that investi- l

gation and serve as a basis for an evaluation of the utility of

this biological process for remediation of other sites across the

Nation. Supporting data from other studies and evaluation of

the process at other sites are discussed in Appendix D.

.

Conclusions

Based on the results of the SITE demonstration project at

the MacGillis and Gibbs site in New Brighton, MN and

information concerning other studies provided by the vendor,

BioTrol, Inc., for different wastes at other sites, several con- l

clusions can be drawn.

e The fixed-film biological treatment system is capable of

destroying substantially all pentachlorophenol(95%+) and

the major portion (>80%) of other phenolics in wastewater

from wood preserving sites. .

* Destruction of >95% can be achieved for a range of other

pollutants, including other halogenated hydrocarbons, benzene, toluene, ethyl benzene, and xylenes (BTEX) from

gasoline, and oxygenated solvents, with final concentrations of specific pollutants well below 1 mg/L achievable e

in some cases.

e Specifically, with input levels of <50 mg/L pentachlorophenol, destruction of 99% and final pentachlorophenol

concentrations well below 1 mg/L are achievable at low

throughput rates and removals of 95+% are achievable at a

flow rate of 5 gpm, equivalent to a residence time of 1.8 l

hours.

e Biodegradation is the predominant mechanism for elimination of pentachlorophenol. Losses by air stripping and

SITE demonstration due to the relatively low concentrations in the influent groundwater. The removal mechanism

for polynuclear aromatic hydrocarbons is probably a combination of biodegradation and adsorption on solids.

Other constituents commonly encountered at such sites,

including oils, suspended solids, and heavy metals, do not

appear to have an adverse effect on bioreactivity. Excessive levels of these contaminants can be removed by

conventional pretreatment if necessary.

Biological treatment and removal of pentachlorophenol

markedly reduces acute biotoxicity of the wastewater,

making it suitable for direct discharge, introduction to a

POTW, or reuse.

The operating cost for the fixed-film biological treatment

is in the range of $2.43 to $3.45/1000 gallons, depending

on system size. Major contributors to cost are labor and

heat requirements, with the labor contribution decreasing

significantly as the scale increases.

One advantage of the BioTrol process over other biological treatment processes is that it does not generate residues

or emissions that would hamper its use, significantly increase operating cost, or require capital investment for

solids separation.

Auxiliary equipment that could be needed to support this

process are comparable to that which would be needed for

other above ground treatment systems, such as oil/water

separators and clarifiers for pretreatment and filters, carbon adsorbers, etc. for effluent polishing to meet discharge

requirements.

With proper acclimation and appropriate bacterial inoculation, the system should be well suited to the treatment of

wastewaters (groundwater, process wastes, lagoon leakage, etc.) containing a wide range of pollutants.

adsorption on solids are very minor contributors to pentachlorophenol removal. Discussion of Conclusions

A mobile (trailer-mounted) system with 5 gpm capacity

* Removal of other pollutants commonly found in contami- was tested at the MacGillis and Gibbs Company site under the

nated waters at wood treatment facilities (e.g., polynuclear Superfund Innovative Technology Evaluation (SITE) proaromatic hydrocarbons) does occur based on results of gram. Extensive data were collected over a six week period to

other BioTrol studies but could not be confirmed in the assess the ability of the system to remove pentachlorophenol

1
and polynuclear aromatic hydrocarbons from groundwater

drawn from an aquifer at the site; the operational requirements

of the system; and the cost of operation. The data from this

study serve as the primary basis for the foregoing conclusions.

Additional supporting evidence was provided for other field

studies by BioTrol.

An extensive Quality Assurance (QA) program was conducted by SAIC in conjunction with EPA’s QA program,

including audits and data review along with corrective action

procedures and special studies to resolve specific data quality

problems. This program is the basis for the quality of the data

derived from the SITE project. Discussion of the QA program

and the results of audits, data reviews, and special studies can

be found in the Technology Evaluation Report.

With the input water essentially fixed in its pollutant

composition, the primary variable that was studied was flow

rate through the system. Three flow rates were selected and

the system was evaluated for about two weeks at each “steady

state” to provide a sound data base. Extensive data were

collected on primary pollutants (penta and PAHs) and on

secondary pollutants (oil, suspended solids, metals, COD,

dioxins, etc.)

The results of the SITE project demonstrated the ability

of the fixed-film, aerobic bioreactor to remove pentachlorophenol. At the flow selected as optimum for the system, 5

gpm, removal of 95+% was achieved and an effluent with

about 1 mg/L of pentachlorophenol was attainable. At lower

flow rates, 1 gpm and 3 gpm, pentachlorophenol removal

increased to 99% and final concentrations down to 0.1 mg/L

were achievable.

Polynuclear aromatic hydrocarbons (PAHs) probably were

also removed, either by biodegradation or by adsorption on/in

the biomass but, unfortunately, the groundwater source itself

contained only low levels of these materials, making it impossible to estimate removal based on differences in analytical

results. Other data from a creosote-contaminated site confirmed that PAHs and other phenolics are efficiently removed.

Other studies reported by the vendor (see Appendix D) confirm that PAHs are removed, probably by a combination of

biodegradation and adsorption on biosolids.

Secondary pollutants, such as oil, suspended solids, and

even heavy metals, did not appear to interfere with the reaction, at least at the concentrations present in the wastewater

studied during the demonstration. Decreases in Total Organic

Carbon (TOC) and oil and grease indicated that the system

removes other organic species as well. This is supported by

data for other studies in which benzene, toluene, ethyl benzene, and xylene (BTEX) and various chlorinated and oxygenated solvents were removed.

Biomonitoring demonstrated that acute toxicity present

in the raw groundwater at the demonstration facility was

essentially totally removed. Coupled with the measured removal of specific chemical species, this suggests that any

form of discharge or reuse would be safe for this wastewater.

2

Based on the demonstration of the BioTrol fixed-film

aerobic reactor at the MacGillis and Gibbs site, there are

several factors that could be critical to successful, cost effective operation at other remediation sites. Possibly first among

these is the temperature, both of the feed stream and of the

ambient air. Since it is recognized that biological reactivity is

dependent on temperature, it is beneficial to maintain a reactor

temperature of about 70°F. If groundwater or air temperatures

are significantly lower, this would require the input of more

heat and, consequently, would increase the electrical cost for

heating. The alternative to heating the wastewater would be

enlarging the system to allow for longer retention time. Thus,

the operating temperature of the system becomes a compromise between operating cost (heat required) and capital cost

(system size) with the final decision dependent on costs and

cleanup deadlines. In the same vein, while the capital cost for

the system ($30,000 for 5 gpm and $80,000 for 30 gpm) does

not include the cost for a building enclosure, one might be

necessary, at least for convenient winter operation in certain

parts of the country.

A second critical factor is the concentration of key pollutants that can be tolerated in the feed water and the level

required in the effluent to meet regulatory requirements. In

other laboratory and field studies it had been demonstrated

that the bioreactor is capable of destroying influent PCP

concentrations in the range of 100-200 mg/L in a single pass

with no evidence of toxicity to the system. In addition, partial

recycle could be used to protect the system against toxicity

(by dilution with the treated effluent) and to achieve high

levels of removal or low effluent concentrations-as long as

capacity is available in a specifically sized system. While

successful operation may still be achievable under such conditions, capital cost would increase significantly. Once-through

operation in a properly scaled unit would be more costeffective under most circumstances.

A third, perhaps less critical, factor is the extent of the

anticipated remediation. A given volume of feedwater, containing a given concentration of pentachlorophenol or other

contaminants, can be equally well decontaminated, i.e., to the

same final effluent concentration, in a 5 gpm or a 30 gpm

reactor, but time constraints and availability of feedwater may

dictate which system is the more cost-effective or the more

desirable.

Other factors that could affect the utility of the system for

removal of PCP or other contaminants include the presence of

other biodegradable organics and oil, suspended solids, and

heavy metals in the feedwater. While the levels of such

contamination encountered in the demonstration project had

no apparent adverse effect, the character of aerobic biological

treatment is such that nutrient requirements may be affected

and interference may be anticipated at some levels (e.g.,

metals). Clearly such problems are surmountable, as by the

incorporation of an oil/water separator, but overall treatment

cost would increase accordingly. However, it must be recognized that such pretreatment would probably be needed for

almost any aboveground treatment system at some level of

contamination. The acidity or alkalinity of the water would

also play a part, at least by affecting the amount of pH

adjustment needed.
Section 2

Introduction

The SITE Program

The EPA’s Office of Solid Waste and Emergency Response (OSWER) and the Office of Research and Development (ORD) established the Superfund Innovative Technology

Evaluation (SITE) Program in 1986 to promote the develop

ment and use of innovative technologies to clean up Superfund sites across the country. Now in its fourth year, the SITE

Program is helping to provide the treatment technologies

necessary to implement new federal and state cleanup standards aimed at permanent remedies, rather than quick fixes.

The SITE Program is composed of two major elements: the

Demonstration Program and the Emerging Technologies Program. In addition, the Program includes research on analytical

methods.

The major focus has been on the Demonstration Program,

which is designed to provide engineering and cost data on

selected technologies. To date, the demonstration projects

have not involved funding for technology developers. EPA

and the developers participating in the program share the cost

of the demonstration. Developers are responsible for demonstrating their innovative systems at chosen sites, usually Superfund sites. EPA is responsible for sampling, analyzing, and

evaluating all test results. The result is an assessment of the

technology’s performance, reliability, and cost. This information will be used in conjunction with other data to select the

most appropriate technologies for the cleanup of Superfund

sites.

Developers of innovative technologies apply to the Demonstration Program by responding to EPA’s annual solicitation. To qualify for the program, a new technology must have

a pilot or full scale unit and offer some advantage over

existing technologies. Mobile technologies are of particular

interest to EPA.

Once EPA has accepted a proposal, EPA and the developer work with the EPA Regional offices and state agencies to

identify a site containing wastes suitable for testing the capabilities of the technology. EPA prepares a detailed sampling

and analysis plan designed to evaluate thoroughly the technology and to ensure that the resulting data are reliable. The

duration of a demonstration varies from a few days to several

months, depending on the type of process and the quantity of

waste needed to assess the technology. While it may be

possible to obtain meaningful results in a demonstration lasting one week using an incineration process, where contaminants are destroyed in a matter of seconds, this is not the case

for a biological treatment process such as the BioTrol process

where contaminant variability, system acclimation, and system stability must be examined over an extended period of

time. In order to evaluate such parameters, it was determined

that a minimum of six weeks of operation, at three different

flow rates, was necessary. After the completion of a technology demonstration, EPA prepares two reports which are explained in more detail below. Ultimately, the Demonstration

Program leads to an analysis of the technology’s overall

applicability to Superfund problems.

The second principal element of the SITE Program is the

Emerging Technologies Program, which fosters the further

investigation and development of treatment technologies that

are still at the laboratory scale. Successful validation of these

technologies could lead to the development of systems ready

for field demonstration. A third component of the SITE Pro

gram, the Measurement and Monitoring Technologies Program, provides assistance in the development and

demonstration of innovative technologies to better characterize Super-fund sites. In this case, EPA had the good fortune to

be able to evaluate such a methodology in conjunction with a

demonstration project, as will be described briefly later in this

report.

SITE Program Reports

The results of the SITE Demonstration Program are incorporated in two basic documents, the Technology Evaluation Report and the Applications Analysis Report. The former

provides a comprehensive description of the demonstration

and its results. The anticipated audience will be engineers

responsible for detailed evaluation of the technology relative

to other specific sites and waste situations. These technical

evaluators will want to understand thoroughly the performance of the technology during the demonstration, and the

advantages, risks, and costs of the technology for the given

application.

The Applications Analysis Report is directed to decisionmakers responsible for selecting and implementing specific

remedial actions. This report provides sufficient information

to determine if the technology merits further consideration as

an option in cleaning up specific sites. If the candidate technology described in the Applications Analysis appears to meet

the needs of the site engineers, more thorough analysis of the

technology based on the Technology Evaluation Report and

information from remedial investigations for the specific site

will be made. In summary, the Applications Analysis will

3
assist in determining whether the specific technology should

be considered further as an option for a particular cleanup

situation.

Purpose of the Applications Analysis Report

Each SITE demonstration will evaluate the performance

of a technology while treating the particular waste found at the

demonstration site. Additional data from other projects also

will be presented where available.

Usually the waste at other sites being considered for

remediation will differ in some way from the waste tested.

Waste characteristic differences could affect waste treatability

and use of the demonstration technology at other sites. Thus,

successful demonstration of a technology at one site does not

assure that a technology will work equally well at other sites.

The operating range over which the technology performs

satisfactorily can only be made by examining a broad range of

wastes and sites. To a limited extent, this report provides an

indication of the applicability of the BATS by examining not

only the demonstration test data but also data available from

other field applications of the technology.

To enable and encourage the general use of demonstrated

technologies, EPA will evaluate the probable applicability of

each technology to sites and wastes in addition to those tested,

and will study the technology’s likely costs in these applications. The results of these analyses will be summarized and

distributed to potentially interested parties through the Applications Analysis Report

Key Contacts

For more information on the demonstration of the BioTrol

Aqueous Treatment System for contaminated groundwater,

please contact:

1. Vendor concerning the process:

BioTrol, Inc.

11 Peavey Road

Chaska, MN 55318

612-448-2515

Dennis D. Chilcote, Vice-president, Engineering

Thomas Chresand, Development Engineer

2. EPA Project Manager concerning the SITE Demonstration:

Mary K. Stinson

U.S. EPA - ORD

Technical Support Branch (MS-104)

2890 Woodbridge Avenue

Edison, NJ 08837-3679

908-321-6683

3. State contact concerning the MacGillis and Gibbs

site:

Mark Lahtinen

Minnesota Pollution Control Agency

Site Response Section

Groundwater and Soil Waste Division

520 Lafayette Road

St. Paul, MN 55155

612-296-7775

4. EPA Regional contact concerning the MacGillis and

Gibbs site:

Darryl Owens

U.S. EPA, Region V

230 South Dearborn Street

Chicago, IL 60604

312-886-7089
Section 3

Technology Applications Analysis

Introduction

This section of the report addresses the potential applicability of the BioTrol Aqueous Treatment System (BATS) to

various other wastewaters and Super-fund site situations where

pentachlorophenol is the pollutant of primary interest. Sup

porting information provided by the vendor, BioTrol, Inc.,

also is referred to as a basis for considering the BATS for

other biodegradable wastes. The demonstration at the MacGillis

and Gibbs site provides the most extensive data base available

to-date and serves as a foundation for conclusions on the

effectiveness and the applicability to other cleanups. The data

base is expanded somewhat by information concerning other

tests that has been provided by the vendor.

The following subsections summarize observations and

conclusions drawn from the current study and supporting

information. Included are factors such as other applicable

wastewaters, site characteristics and constraints, applicability

of state and federal environmental regulations, unique handling requirements, and personnel factors. Additional information on the BioTrol technology, including a process

description, vendor claims, a summary of the Demonstration

Test Results and Case Studies of other investigations are

provided in the Appendices.

Conclusions

Based on the results of the demonstration test program at

the MacGillis and Gibbs site and other information, the

vendor’s key claims are substantiated. The process can extensively degrade pentachlorophenol. Pentachlorophenol levels

of well under 1 mg/L are achievable, at least at reduced

throughput rates, while percent removals of at least 95% are

achievable even at the highest flow rate tested, 5 gpm. It

appears that conversion to inorganics (mineralization), carbon

dioxide, water, and chloride ion, rather than to other, intermediate organics occurs, but the data on chloride production and

TOC removal are not sufficiently precise to verify this point.

A second claim, that polynuclear aromatic hydrocarbons

are removed, could not be confirmed due to low levels of

PAHs in the incoming groundwater studied in the SITE test

program and relatively high detection limits in the GC/MS

procedure used to measure the PCP. The concentrations of the

individual PAHs in the effluent were, with one exception,

below detection limits (10-100 pg/L). Other investigations of

PAH-contaminated waters using the BATS have demonstrated

successful removal of PAHs, as noted in Appendix D.

On the basis of acute biomonitoring tests, the BATS

process is capable of converting wastewaters that are toxic (to

certain species, at least) to a non-toxic effluent that should be

suitable for discharge, reuse, or further treatment at a POTW.

The operating costs for the process are estimated on the

basis of the 5 gpm mobile pilot plant and other data available

from BioTrol at between $3.45 and $2.43/1000 gallons for 5

gpm and 30 gpm systems, respectively. Depending on how a

system is used, total operating plus capital cost could be as

low as $2.94/1000 gallons.

The process provides a rapid, compact means of detoxifying and decontaminating wood preserving wastewaters, even

when significant quantities (-50 mg/L) of dispersed oil are

present. The BATS has also proven to be effective on other

wastewaters containing a wide range of contaminants including the benzene, toluene, ethyl benzene, xylene (BTEX) mixture resulting from gasoline contamination, where >99%

removal of benzene was achieved; a solvent mixture containing methyl ethyl ketone, cyclohexanone, and tetrahydrofuran

where >99% removal was also achieved even at an influent

COD concentration of 3 100 mg/L; and total phenolics from a

creosote waste with a high COD (-1500 mg/L) loading where

phenolics removal was >99%.

The system is simple to operate and requires a minimum

of operator attention or maintenance once the bacterial population has been established.

Discussion of Conclusions

The SITE Program demonstration at the MacGillis and

Gibbs Company facility in New Brighton, MN clearly indicated that at the maximum tested flow rate of 5 gpm the

mobile unit was capable of destroying 95+% of the PCP.

Operation during the demonstration at lower flow rates, i.e., at

longer retention times, demonstrated that even higher PCP

removal levels could be achieved along with final PCP concentrations much below 1 mg/L. Thus, depending on the

nature of the contaminated water and the effluent quality

limits imposed, a BATS could be operated successfully.

Pentachlorophenol Removal

The concentration in the available groundwater (<45

mg/L) precluded evaluation of the system’s capability at

higher PCP concentrations. However, other work by BioTrol

using wastewater containing in the range of 100 mg/L PCP

5
demonstrated that the technology was effective (90% removal, effluent PCP concentration of -4 mg/L) at higher

influent concentrations. Based on other studies, BioTrol has

reason to believe that PCP concentrations even higher than

100 mg/L can be tolerated and degraded without adversely

affecting the viability of the bioreaction. It is recognized that

some level of PCP may be reached where a wastewater would

be toxic to the biological growth. At such levels dilution (with

fresh water or with recycled effluent) could be used to decrease the “apparent*’ concentration and still allow use of the

BioTrol technology, albeit at a decreased flow rate.

Mineralization of Pentachlorophenol

Analyses of influent and effluent for chloride and TOC

were carried out in an effort to confirm that the removal of

PCP occurred by total degradation to water, carbon dioxide,

and chloride ions rather than to intermediate, partially chlorinated products that simply were not detected by the analytical

protocol. While the changes in both chloride and in TOC were

consistent with total degradation (mineralization) of the PCP,

the changes in both parameters exceeded the expected values.

In the case of the chloride, it is suggested that other chlorinated species may account for the high value. Similarly,

degradation of other organics, including oil and grease and

other organic species not detected by the GC/MS methodology, may explain the TOC results.

Polynuclear Aromatic Hydrocarbon Removal

While the vendor, BioTrol, claimed that polynuclear aromatic hydrocarbons (PAHs) such as those expected from

creosote contamination of the soil and groundwater were also

destroyed by the bacteria, constraints in the analytical procedures make it impossible to validate this claim and it can only

be concluded that only low concentrations (< detection limits)

of any polynuclear aromatic hydrocarbons are present in the

effluent.

In a pilot scale study at another wood preserving site,

>80% removal of PAHs was demonstrated. These results also

indicated that both biodegradation and adsorption on biosolids

contributed to PAH removal from the aqueous waste stream.

Operational ReliabilitylStability

The system proved to be quite stable and required a

minimum of attention over the course of the six weeks of

study. Other than some attention to a leaking pump, routine

checking of pH, and preparation of nutrient solutions, there

was little need for an operator. Certainly, with a large reservoir of relatively constant feed water, such as a contaminated

aquifer, the attention required would be minimal. In such

instances it would be desirable to incorporate some means of

on-line monitoring to assure that out-of-compliance effluent

is recycled rather than discharged when no operator is present.

At least some portion of the observed variability in results

probably is attributable to sampling and analytical variations.

Costs

Cost data was developed for the 5 gpm pilot plant unit on

the basis of the experience at the MacGillis and Gibbs site and

other studies by BioTrol with the larger, 30 gpm unit. Other

than some savings achievable by buying nutrients in bulk, the

major factors in operating cost are utilities to provide heat and

the labor to oversee the operation; it is expected that the labor

cost for other biological systems such as activated sludge

would be even higher.

Applicable Wastes

While this study of the BioTrol Aqueous Treatment System was limited to a single wastewater, the groundwater

available at the MacGillis and Gibbs site, the results of the

study along with other results provided by the vendor suggest

that the technology would have wide applicability to other

contaminated groundwaters and process waters. The design of

the system is such that elevated concentrations of contaminants in the incoming stream do not affect operation, although

they can be a factor in determining the throughput rate achievable at a particular installation and the nutrient cost contribution to operation. In other words, if a source of

PCP-contaminated water contains significantly higher levels

of PCP, the safe approach may be to dilute the stream, either

with clean water or with effluent, at least until acclimation can

be demonstrated. Based on other results provided by BioTrol,

the system is well able to withstand and degrade wastewaters

containing as much as 100 mg/L of PCP and probably more

on a once-through basis. COD concentrations of up to 3000

mg/L (from BTEX and oxygenated solvents) have been successfully treated in a single pass by the BATS using only

indigenous microorganisms.

Temperature, dissolved oxygen, and pH of an incoming

wastewater could affect the biological reaction, except that

the system incorporates means for bringing these parameters

into line with specifications. The experience at MacGillis and

Gibbs did not indicate nor suggest a particular sensitivity to

any of these factors. While reduced temperature would be

expected to decrease the degradation rate in any biological

treatment system, the BATS is equipped with a heater and a

heat exchanger to maximize the utilization of energy intro

duced to heat a cold influent. Based on engineering calculations by BioTrol, the heat losses in the system are equivalent

to only a few degrees.

One other factor that was given careful consideration at

the outset of the demonstration was the question of oil in the

influent. During the demonstration, the system was operated

with a water source containing approximately 50 mg/L of oil

with no apparent adverse effect; in fact, the oil was significantly reduced in the effluent, either by adsorption or by

degradation. If necessary, an oil/water separator could be

incorporated in the process train, which should reduce the oil

and grease (O/G) level to well below that tested in this

demonstration.

6
Other pollutants in the incoming water, such as metals, do

not appear to adversely affect the reaction efficiency, at least

at the levels encountered at the MacGillis and Gibbs site.

There is little reason to suspect that the BioTrol process would

be more (or less) sensitive to metals than any other biological

system.

The proven track record of biological treatment for many

wastewaters contaminated with organics suggests the applicability of this technology to other wastes. The BioTrol process,

requiring minimal reactor volume and providing high removal

rates at relatively high influent concentrations of specific

contaminants by virtue of the plug flow design, should be

well-suited to other wastes. The system’s use of an inoculum

of a waste-specific bacterium for particularly recalcitrant pollutants such as PCP suggests that the process could be “customized” to other constituents where indigenous

microorganisms are not present.

Site Characteristics

In the demonstration program a mobile pilot plant system

was used that required only a level base (ideally a concrete

pad); potable water and power were supplied by the site

operator. If necessary, the small amount of potable water

needed could be trucked in and power could be provided by an

on-site generator. In any case where groundwater was being

brought up by pump from a well for treatment, power for that

pump would have to be provided. If the water being treated

were surface water (e.g., a storage lagoon), this might not be

necessary. In either case, placement of the system close to the

water source would reduce pumping requirements.

Geography could play a small role in the effectiveness of

the BioTrol system, as it would with any biological treatment.

Significantly colder ambient temperatures can reduce biological reaction rates. As noted earlier, the BioTrol system is

equipped with a heat exchanger and heater and low ambient

temperatures can be traded-off for a [small] increase in heat

input, since most heat can be reclaimed.

With the demonstrated ability of the vendor’s system to

reduce pentachlorophenol levels to well below 1 mg/L, acceptance of the effluent by POTWs should not be a problem in

most communities. Even direct discharge to receiving waters

may be defensible in light of the analytical and biomonitoring

results obtained at the MacGillis and Gibbs site. Reuse of the

treated wastewater should also be attractive since the only

additions to the water would be small amounts of nutrients

and salt. These conclusions are based on the MacGillis and

Gibbs groundwater and would have to be reconfirmed for any

other wastewater.

Environmental Regulation Requirements

Anticipating that the BioTrol system would be used on

groundwater at a contaminated site, a first concern would be

local well-drilling requirements. Depending on the size of

these wells, their capacity, and the capacity of the treatment

system being installed, storage tanks may be desirable as a

reservoir and to provide needed equalization. Such tanks may

need regulatory attention (permits, materials, etc.), depending

7

on their size and whether they are placed above or below

ground.

It is probable that the treated effluent from any similar

site would be suitable for direct discharge or discharge to a

POTW as “pretreated”. At most, a NPDES permit (or state

equivalent) should be required. However, under the Resource

Conservation and Recovery Act of 1976 (RCRA) and the

Hazardous and Solid Waste Amendments of 1984 (HSWA),

there is some question as to whether the effluent, as a residual

from treatment of a hazardous waste, would itself be considered hazardous, in spite of its apparent nonhazardous character.

Under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) and the

Superfund Amendments and Reauthorization Act of 1986

(SARA), EPA is responsible for determining the methods and

criteria for the extent of removal. The utility and cost effectiveness of the BioTrol system would, to an extent, be dependent on the final level deemed appropriate and necessary at a

particular site by EPA. However, since the use of remedial

actions by treatment that “ . ..permanently and significantly

reduces the volume, toxicity, or mobility of hazardous substances” is strongly recommended (Section 121 of SARA),

the BioTrol system would appear to be an attractive remedy

for a site contaminated with wood preserving chemicals.

SARA also added a new criterion for assessing cleanups

that includes consideration of potential contamination of the

ambient air. This is in addition to general criteria requiring

that remedies be protective of human health and the environment. This demonstration has established that pentachlorophenol is not emitted to the ambient air. However, from a

worker and environment safety point of view, it still may be

desirable to incorporate an air treatment system (e.g., carbon)

to assure that the escape of the more volatile PAHs such as

naphthalene and 2-methyl naphthalene is minimized, even

though the observed level of naphthalene at the MacGillis and

Gibbs site (=<l mg/L) is well below the OSHA Permissible

Exposure Limit of 10 mg/L. And, if such a control system is

installed to collect the emissions from the reactor, a state or

local permit to construct and operate an air emissions control

unit may be required.

Finally, the very limited data on dioxins/furans and their

frequent occurrence in conjunction with chlorocarbon products suggest that it would be prudent to evaluate whether the

small volume of sludge produced from the BioTrol system has

to be considered to be dioxin-contaminated and managed in

accordance with RCRA, thereby increasing total cost somewhat. Concurrently, any carbon used in an air treatment

system or for effluent polishing at a particular site would also

have to be tested to determine whether it is contaminated with

dioxins, in which case special handling would also be necessary.

Materials Handling Requirements

If the BioTrol system is to be used to treat groundwater,

the first need is a well drilling rig to provide the well(s) from

which the feedwater is to be obtained. Once the wells are
drilled and developed, each must be equipped with a pump to

draw up the necessary feed water. Local well drilling requirements would have to be taken into consideration.

If the vendor’s system is provided with relatively clean

ground- or process water, little special handling is needed

other than pH and temperature adjustment and these needs are

incorporated in the system. The demonstration has also shown

that a reasonably high level of oil (-50 mg/L) has no effect.

The vendor indicates that significantly higher levels of oil can

be tolerated. However, in the event that even higher levels are

present in a source water, a simple oil/water separator should

suffice to reduce the, level to an acceptable level (see Appendix D-l). Similarly, a clarifier could be added to remove high

levels of suspended solids.

Operationally, the only problem encountered was the

apparent backmixing through the underflow weirs separating

each chamber. This seemed to have no effect on the effluent

quality, and may only influence decisions as to sampling

points in future installations.

While groundwater tends to be reasonably consistent

over time, such may not be the case with other wastewaters. In

certain cases it may be desirable to install a storage tank or

even a lagoon for equalization and to avoid shock loading that

could, conceivably, adversely affect biological activity. Depending on their design, the regulatory impacts of such tanks

or basins could need to be considered.

If a large source of contamination were being treated, it

would be cost-effective to purchase nutrients and caustic in

bulk. In that event storage facilities would be required.

Personnel Issues

Even during acclimation, the system requires little attention. Nutrient addition and pH adjustment are carried out

automatically. Consequently, there is little labor requirement

other than to assure that all pumps are operating, nutrient and

caustic reservoirs are filled, and that the final effluent is

meeting discharge requirements. Some additional time would

be required if oil/water separation, suspended solids removal,

or effluent polishing is required at a particular installation.

Consideration should be given to equipping operators working on or near the system with skin and respirator protection if

exposure could occur by contact with liquid or mist when

opening the bioreactor, or to air emissions stripped from the

system.

Testing Issues

At this time, the only approved method for pentachlorophenol analysis during monitoring is the GC/MS method for

semivolatiles. This is a costly and time-consuming procedure

not well suited to on-line use for process control or effluent

monitoring. BioTrol has developed a high pressure liquid

chromatographic (HPLC) procedure which is much faster and

may be acceptable to site management and regulatory personnel for routine use. A comparison of the BioTrol HPLC

procedure and the EPA method conducted as part of the QA

program for the demonstration indicated that the BioTrol

method is accurate for samples containing PCP concentrations of 1 mg/L or higher.

EPA’s Environmental Monitoring Systems Laboratory

(EMSL) also is evaluating an alternate immunoassay technique that would be well suited to field use and would be very

economical. At this time, whether the field test provides

comparable results has not been validated and widescale

application is certainly several years away. As with any

analytical procedure, it also would be necessary to establish

that the waste matrix at a particular site does not interfere with

the quality of results.

8
Section 4

Economic Analysis

Introduction

The primary purpose of this economic analysis is to

estimate costs (not including profit) for commercial-scale

remediation using the BioTrol Aqueous Treatment System

(BATS). With realistic costs and a knowledge of the bases for

their determination, it should be possible to estimate the

economics for operating similar-sized systems at other sites

utilizing various scale-up cost formulas available in the literature such as the “six-tenths rule”.

This economic analysis is based on assumptions and

costs provided by BioTrol and on results and experiences

from this SITE demonstration developed over two weeks of

operation at 5 gpm. It is assumed that the performance of

commercial-scale equipment will be the same as that demonstrated here for a pilot-scale 5 gpm mobile unit with an

influent containing approximately 45 ppm of penta and achieving 95% removal. Certain actual or potential costs were

omitted because site-specific engineering aspects beyond the

scope of this SITE project would be required. Certain other

functions were assumed to be the obligation of the responsible

parties or site owner and also were not included in the

estimates. Cost figures provided here are “order-of-magnitude” estimates, generally +50%/-30%, and are representative

of charges typically assessed to the client by the vendor

exclusive of profit.

The reader is also urged to obtain and review the Applications Analysis Report for the companion study, in which the

BATS is used to treat process water from a soil washer.

Conclusions

l The cost to treat groundwater using the BATS in three

different configurations is given below:

Configuration $/1000 gal.

5 gpm leased mobile unit 14.56

5 gpm purchased fixed unit 4.61

30 gpm purchased fixed unit 2.94

* For the 5 gpm leased mobile unit, the largest cost component is the equipment lease rate (76%). followed by utilities (11%). and labor (10%). For the 5 gpm purchased

fixed unit, the largest cost component is utilities (37%)

followed by labor (32%), and capital equipment (25%).

On a $/lOOO gal basis, capital equipment costs for the fixed

unit appear to be an order of magnitude less than for the

mobile unit. It should be remembered, however, that an

initial investment of $30,000 is required to purchase the

fixed unit.

. Buying a 5 gpm treatment system would be economical if

it is to be used for at least 12 months.

l For fixed units there are economic advantages due to scale,

especially for labor. On a $/1000 gal basis, utilities are the

largest cost component followed by labor and equipment

costs. However, there is a point of diminishing returns. A

six-fold increase in size resulted in a 35% reduction in

costs.

l In all instances, influent heating accounted for a disproportionate share of operating costs (l0-50%). Influent heating

may not always be necessary. And even when it is necessary, it will be used only during the colder months.

l In no instance did consumables and supplies account for

any more than 10% of total cleanup costs.

Issues and Assumptions

This section summarizes the major issues and assumptions used to evaluate the cost of BioTrol’s Aqueous Treatment System. In general, assumptions are based on information

provided by BioTrol. Certain assumptions were made to account for variable site and waste parameters and will, undoubtedly, have to be refined to reflect site specific conditions.

Waste Volumes and Site Size

The volume of groundwater to be treated at the MacGillis

and Gibbs Superfund site has not yet been determined. Because cleanup objectives have not yet been established, it is

not clear as to exactly how BioTrol will propose to remediate

the site. Pumping and treating the groundwater already there

may be sufficient to stop the plume from spreading, but

insufficient to reduce the contaminant concentration in new

groundwater that will seep in. To accomplish this goal, a

larger volume of groundwater will have to be treated for a

much longer period of time. To bypass this question, costs are

given per 1000 gal of groundwater treated

System Design and Performance Factors

Figure C-3 in Appendix C shows a simplified flowsheet

of BioTrol’s pilot-scale Aqueous Treatment System. It was

9
assumed that a commercial-scale unit would be similar in

design and performance to that demonstrated under the SITE

program.

For the purposes of this analysis, it was not necessary to

assume a particular contaminant concentration. It was assumed that the performance of a commercial-scale unit would

be the same as that demonstrated here and that this level of

reduction would be sufficient so as not to require any further

treatment.

The cost estimates do not include provisions for oil/water

separation, suspended solids removal, exhaust air collection

and/or treatment, or effluent polishing since these items are

completely site and waste specific.

System Operating Requirements

Although the volume of the reactor is designed to give a

certain level of reduction for a certain residence time at its

design flow rate, it is entirely possible to operate the unit at a

lower flowrate and increase the residence time to increase

contaminant reduction. Examination of such flowrate variation was attempted in this study but, unfortunately, influent

contaminant concentrations varied too much to draw any

definitive conclusions. Decreased flowrate would increase the

cleanup time and the associated costs. For this analysis, all

units were assumed to be operated at their design flowrates

and that this was sufficient to achieve the desired reduction.

It was assumed that the BATS would operate 24 hours

per day, 7 days per week. One lead operator would be required

approximately 10 hr/week to attend to the unit

Utilization Rates and Maintenance Schedules

Costs per 1000 gal have not assumed any downtime.

Since this is a continuously operating, steady-state system

with very few moving parts, utilization rates should be quite

high. Two weeks for mobilization and training and one week

for demobilization were assumed.

Financial Assumptions

For the purpose of this analysis, capital equipment costs

were amortized over a 10 year period with no salvage value.

Interest rates, time-value of money, etc. were not taken into

account.

Basis for Economic Analysis

In order to compare the cost-effectiveness of technologies in the SITE program, EPA breaks down costs into 12

categories shown in Table 1 using the assumptions already

described. The assumptions used for each cost factor are

described in more detail below.

Site Preparation Costs

The amount of preliminary preparation will depend on

the site and is assumed to be performed by the responsible

party (or site owner). Site preparation responsibilities include

site design and layout, surveys and site logistics, legal searches,

access rights and roads, and preparations for support facilities,

decontamination facilities, utility connections, and auxiliary

buildings. Since these costs ate site-specific, they are not

included.

Additionally, well drilling and preparation are assumed

to be performed by the responsible party (or site owner) and

are also highly site-specific. Hence, these costs are also not

included.

Permitting and Regulatory Costs

Permitting and regulatory costs are generally the obligation of the responsible party (or site owner). These costs may

include actual permit costs, system health/safety monitoring,

and analytical protocols. Permitting and regulatory costs can

vary greatly because they are very site- and waste-specific. No

permitting costs are included in this analysis, however, depending on the treatment site, this may be a significant factor

since permitting can be a very expensive and time-consuming

activity.

Equipment Costs

Capital equipment costs were provided by BioTrol, Inc.,

for three configurations:

a. A 5 gpm mobile unit that would be leased for $2400/

month. This would be suitable for short term cleanups.

b. A 5 gpm skid mounted unit which could be purchased

for $30,000. This could be used for long term treatment

of a relatively low flow stream such as leachate from a

pond.

c. A 30 gpm skid mounted unit which could be purchased

for $80,000. This could be used to treat a larger aquifer.

The 5 gpm and 30 gpm purchased units were amortized

over a 10 year period with no salvage value assumed at the

end. This works out to $250/mo for the 5 gpm installation and

$667/mo for the 30 gpm installation.

To determine costs per 1000 gal of water treated, these

monthly amortized costs were divided by the respective

flowrates expressed in gal/ma. (assuming 24 hr/day and 30

days/mo). The reader is cautioned to use these numbers with

great care due to the amortization assumptions just made.

Capital costs per 1000 gal may appear to be the lowest for the

30 gpm unit but an $80,000 investment is required up front.

For short cleanup times this is clearly uneconomical. Likewise, for the 5 gpm skid mounted unit, a cleanup time of more

than 12 months would make this purchase option more economically attractive than leasing a unit.

Startup

As the name implies, the 5 gpm mobile unit is designed to

be moved from site to site. Transportation costs are only

charged to the client for one direction of travel and are usually

included with mobilization rather than demobilization. Trans10
Table 1. Estimated Costs for MacGillis and Gibbs Site

portation costs are variable and dependent on site location as

well as on applicable size/weight load permits, which vary

from state to state. The total cost will depend on how many

state lines are crossed. For purchased units, transportation

costs are borne by the buyer.

The amount of assembly required for the mobile unit is

minimal. For the purchased units, assembly is a labor intensive operation consisting of unloading equipment from trucks

and trailers used for transportation, as well as actual assembly.

Mobilization, training, and acclimation are estimated to take 1

person working a 40 hr week about 2 weeks and this time

should be included in the total time on site.

Depending on the site, local authorities may impose

specific guidelines for health and safety monitoring programs.

The stringency and frequency of monitoring required may

have a significant impact on project costs.

Labor

Once the system is acclimated and operating at steady

state, very little additional labor is involved. It is estimated

that a Project Engineer at $35/hr would spend 1 hr/week and a

Lead Operator at $25/hr would spend 10 hr/week on the 30

gpm unit and 5 hr/week on the 5 gpm unit for maintenance

and operation. These numbers include salary, benefits, and

administration/overhead costs but exclude profit. BioTrol calculates the labor to be $1.49/1000 gal for the 5 gpm units and

$0.50/1000 gal for the 30 gpm unit. No provisions for per

diem or car rental have been included in these figures.

Consumables and Supplies

Caustic usage would be determined by the pH and alkalinity of the incoming water to be treated. For purposes of this

cost estimate, usage was assumed to be the same as that

demonstrated under this SITE project (.09 gal of 50% solution

per 1000 gal of water treated). More or less caustic may be

requited at another site; however, caustic use should remain

essentially constant throughout the treatment of a specific

waste. For a commercial scale cleanup, a cost of $2.60/gal of

50% solution was assumed. Thus, the cost would be $0.24/

1000 gal of water.

Nutrients in the form of urea and trisodium phosphate

dissolved in water in a 2:1 weight ratio are usually added

regardless of system size. At the MacGillis and Gibbs demonstration site, a nutrient mixture consisting of 5 lb urea plus 2.5

lb of trisodium phosphate dissolved in 50 gallons of water was

added at a rate of 2.5 ml/gallon of wastewater. For the 5 gpm

units, the prices given reflect purchase of the ingredients at a

local fertilizer supplier; for the larger system some economy

of scale has been factored in on the assumption that the two

materials would be purchased in bulk. The cost for storage

facilities should be included in site preparation.

Two other items that should be considered but were not

included are health and safety gear, and maintenance supplies

(spare parts, oils, grease and other lubricants, etc.). Since the

manpower requirements for both systems are the same, the

cost for health and safety gear will be minimal (about $500).

The cost of maintenance supplies can be assumed not to

exceed 2% of the capital costs on a yearly basis.

11
Utilities

The total electrical demand for both units is estimated to

be about 10 HP. This includes the pump used to deliver the

groundwater to the BATS, a second pump to discharge the

water against an assumed head of 50 ft of water within the

BATS, and an air sparger blower. Electricity required for the

air sparger blower motor will decrease somewhat for the 30

gpm unit since the reactor chambers would be 8 ft deep rather

than the nominal 4 ft used in the 5 gpm unit, providing more

efficient “capture” of the dispersed air. However, there would

also be a somewhat higher head pressure. The vendor’s calculations indicate the benefit will be minimal and the same value

has been used for both size units. It does not include electricity that may be required to heat the influent. Electricity was

assumed to cost $0.06/kw-hr.

The amount of heat required at a particular site would be

dependent on the incoming water temperature, the ambient

temperature and resulting heat loss, as well as the exothermicity of the reactions for a particular wastewater. Practically, the

heat exchanger can transfer or return enough heat from the

effluent so that the difference is only about 31;. Coupled with

an assumed 2’F loss to the atmosphere, the actual difference

between influent and effluent will only be about 5°F and is

essentially independent of the temperature of the water source

except during the startup. At the MacGillis and Gibbs site

during July to September, the average groundwater temperature was 55°F. (13°C) and the heater was not used. A difference of 5°F between influent and effluent temperatures and

electricity at $0.06/kw-hr were assumed.

Effluent Treatment and Disposal

The effluent from the BATS can be handled several

ways. It can be injected back into the ground to effectively

“flush out” contaminant from the soil. In this case, the effluent

contaminant concentration is not a critical parameter. If the

effluent is clean enough to meet regulatory standards, it may

be discharged to a POTW. If the effluent is not clean enough

to meet regulatory standards, it may be recycled and mixed

with the influent for further treatment. This will obviously

extend the required cleanup time and the associated costs.

There obviously are too many variations for each one of

these scenarios to be considered here. For simplicity, it will be

assumed that the effluent is clean enough to meet regulatory

standards and hence can be directly discharged to a POTW

without further treatment.

ResidualslWaste Shipping, Handling and

Transport Costs

Waste disposal costs, including storage, transportation,

and treatment costs, are assumed to be the obligation of the

responsible party (or site owner). It is assumed that residual or

solid wastes generated from this process would consist only of

contaminated health and safety gear, used filters, spent activated carbon, etc. Landfilling is the anticipated disposal method

for this material at an estimated cost of $100/drum.

Analytical Costs

No analytical costs during operations are included in this

cost estimate. Standard operating procedures for BioTrol do

not require planned sampling and analytical activities. Periodic spot checks may be executed at BioTrol’s discretion to

verify that equipment is performing properly and that cleanup

criteria are being met, but costs incurred from these actions

are not assessed to the client. The client may elect, or may be

required by local authorities, to initiate a sampling and analytical program at their own expense.

Facility Modification, Repair and Replacement

costs

As stated earlier, site preparation costs are assumed to be

borne by the responsible party (or site owner). Likewise, any

modification, repair, or replacement to the site was assumed

to be done by the responsible party (or site owner).

Demobilization Costs

It is estimated that demobilization would take about 1

week. Site cleanup and restoration is limited to the removal of

all equipment and facilities from the site. Grading or

recompaction requirements of the soil will vary depending on

the future use of the site and is assumed to be the obligation of

the responsible party or site owner.

Results

Table 1 shows several interesting trends regarding mobile

and fixed units as well as the size of fixed units.

For the 5 gpm mobile unit, the largest cost component is

the equipment lease rate (76%) followed by utilities (11%).

and labor (10%). Comparing this with the 5 gpm fixed unit,

the largest cost component is utilities (37%). followed by

labor (32%), and capital equipment (25%). The reader is

cautioned to view these relative percentages carefully.

Although capital equipment costs appear to be an order of

magnitude less on a $/1000 gal basis, an initial investment of

$30,000 must be made for the 5 gpm fixed unit. Such a capital

outlay can only be justified for long duration or large cleanups. The breakeven decision point between a fixed and mobile

unit is 12 months ($30,000 for fixed unit + $2,400/mo for

mobile unit). Therefore, even if a 5 gpm fixed unit is not used

for the full 10 year period assumed here, it might be economical to purchase the equipment if it is to be used for at least 12

months. The decision will be influenced by other financial

considerations, i.e., interest rates, time value of money, cash

flow, etc.

Secondly, influent heating accounts for a disproportionate amount of operating costs. As noted earlier, influent

heating may not be necessary in the majority of cases. Even

when it is required, it will only be used during the coldest

months of the year. Additionally, influent heating was assumed to be done relatively expensively using electricity. A

gas, oil-fired, or solar heat exchanger could accomplish this

12
much more efficiently. These points should be kept in mind

when comparing total cleanup costs on a $/l000 gal basis.

Differences between the 5 gpm and 30 gpm fixed units

are less dramatic. Utilities are still the largest cost component

(37% for the 5 gpm unit, 57% for the 30 gpm unit), but

capital equipment and labor costs have a more equal share for

the 30 gpm unit. This, in part, is no doubt due to economy of

scale, especially the labor cost component, which is half the

amount of the 5 gpm unit, Again, heating accounts for a

disproportionate share of operating costs. In no instance did

consumables and supplies account for any more than 10% of

total cleanup costs.

Comparison of total cleanup costs on a $/l000 gal basis

indicates that there is a point of diminishing returns, as

expected. A six-fold increase in size amounts to about a 35%

reduction in costs.

In all of the above analysis, it should be remembered that

costs for only 4 out of the 12 cost components were considered. If the additional factors are taken into account, costs

could increase significantly.

13
Section 5

Bibliography

1

2.

3.

4.

5.

6.

7,

8.

9.

10.

11.

Bishop, J., GAINING ACCEPTANCE, Hazmat TEMS, Environmental Science and Technology,

World, June 1989, p. 37 ffd. 24,#5,654-66l (1990).

Brown, EJ., et al, PENTACHLOROPHENOL

DEGRADATION: A PURE BACTERIAL CULTURE AND AN EPILITHIC MICROBIAL CONSORTIUM, Applied and Environmental Microbiology, July 1986, p. 92-97.

12. Lee, K.M. and H.D. Stensel, AERATION AND

SUBSTRATE UTILIZATION IN A SPARGED

PACKED-BED BIOFILM REACTOR, J. Water

Pollution Control Federation, 58 #11, 1066-1072

(1986).

Bourquin, A.W., BIOREMEDIATION OF HAZARDOUS WASTE, HMC, Sept./Oct. 1989, p. 16 ffd

13.

Dworkin, D. and R.M. Shapot, INNOVATIVE

REMEDIAL TECHNOLOGIES AT A CREOSOTEBASED WOOD TREATMENT PLANT, presented at

I-IAZMAT ‘88, Nov. 8- 11.1988.

Loper, J.C., THE FUTURE OF BIOREMEDIATION

PROSPECTS FOR GENETICALLY ENGINEERED

MICROORGANISMS, HMC, Sept./Oct. 1989, p. 24

ffd.

14. Mathewson, J.R. and R.B. Jones, COMMERCIAL

MICROORGANISMS, Hazmat World, June 1989 p.

48-51.

EPA, BIOLOGICAL TREATMENT OF

CHLOROPHENOLIC WASTES, Final Report,

Project No. 12130 EGK, June 1971.

15.

EPA, METHODS FOR CHEMICAL ANALYSIS OF

WATER AND WASTES, U.S. EnvironmentaI

Protection Agency, EnvironmentaI Monitoring and

Support Laboratory, Cincinnati, OH., EPA-600/4-79-

020. Revised March 1983.

Mueller, J.G., PJ. Chapman and P.H. Pritchard,

CREOSOTE-CONTAMINATED SITES-THEIR

POTENTIAL FOR BIOREMEDIATION, Environmental Science and Technology, 23, #10, 1197-1201

(1989).

16. Nicholas, R.B. and DE. Giamporcaro, NATURE’S

PRESCRIPTION, Hazmat World, June 1989, p. 30

ffd.

EPA, SUPERFUND INNOVATIVE TECHNOLOGY

EVALUATION (SITE) STRATEGY AND PROGRAM PLAN, EPA/540/G-86/001, Dec. 1986.

17.

EPA, TEST METHODS FOR EVALUATING

SOLID WASTE, SW-846, U.S. Environmental

Protection Agency, US Government Printing Office,

Washington, DC, Third Edition, Nov. 1986.

PEI Associates, Inc., REMEDIAL ALTERNATIVES

REPORT FOR THE MACGILLIS AND GIBBS CO.

HAZARDOUS WASTE SITE IN NEW BRIGHTON,

MINNESOTA, for Twin City Testing and Engineering Laboratory Inc., State PMN Contract No. 13726,

Subcontract No. l-35086, PN 3686, April 1987.

18.

FinIayson, G., MICROBIAL CLEANUP OF TOXIC

WASTES MAY PROVIDE ALTERNATIVE

SOLUTION, Occupational Health and Safety, Jan.

1990, p. 36,38,40,57.

Piotrowski, M.R., BIOREMEDIATION: TESTING

THE WATERS, Civil Engineering, Aug., 1989, p. 51-

53.

Kennedy, M.S., J. Grammas and W.B. Arbuckle,

PARACHLOROPHENOL DEGRADATION USING

BIOAUGMENTATION, Research J. Water Pollution

Control Federation, 62 #3,227-233 May/June 1990.

19.

20.

Rusten, B., WASTEWATER TREATMENT WITH

AERATED SUBMERGED BIOLOGICAL FILTERS,

J. Water Pollution Control Federation, 56 #5,424-431

(1984).

Lee, L.S., et al, INFLUENCE OF SOLVENT AND

SORBENT CHARACTERISTICS ON DISTRIBUTION OF PENTACHLOROPHENOL IN

OCTANOL-WATER AND SOIL-WATER SYSSaber, D.L. and R.L. Crawford, ISOLATION AND

CHARACTERIZATION OF FLAVOBACTERIUM

STRAINS THAT DEGRADE PENTACHLOROPHENOL, Applied and Environmental Microbiology,

Dec. 1985, p. 1512-1518.
21.

22.

23.

24.

Skladany, GJ. and K.M. Sullivan, “DECAY

THEORY” BIOLOGICAL TREATMENT FOR

LOW-LEVEL ORGANIC CONTAMINATED

GROUNDWATER AND INDUSTRIAL WASTE,

Superfund ‘87 Conference (I-IMCRI), Nov. 17.1987.

Washington, D.C.

Steiert, J.G. and R.L. Crawford, MICROBIAL

DEGRADATION OF CHLORINATED PHENOLS,

Trends in Biotechnology, 3, #12,1985, p. 300-305.

Stinson, M.K., W. Hahn and H.S. Skovronek, SITE

DEMONSTRATION OF BIOLOGICAL TREATMENT OF GROUNDWATER BY BIOTROL, INC.

AT A WOOD PRESERVING SITE IN NEW

BRIGHTON, MN, Presented at 16th Annual EPA

Research Symposium, Cincinnati, OH, April 3-5,

1990.

Topp, E., R.L. Crawford, and R.S . Hanson, INFLUENCE OF READILY METABOLIZABLE CARBON

ON PENTACHLOROPHENOL METABOLISM BY

A PENTACHLOROPHENOL-DEGRADING

FLAVOBACIERIUM SPECIES, Applied and

25.

26.

27.

28.

Environmental Microbiology, Oct. 1988, p. 2452-

2459.

Torpy, M.F., HF. Stroo, and G. Brubaker, BIOLOGICAL TREATMENT OF HAZARDOUS WASTE,

Pollution Engineering, May 1989, p. 80 ffd.

Twin City Testing Corp., REMEDIAL INVESTIGATION REPORT: MACGILLIS AND GIBBS COMPANY SITE, NEW BRIGHTON, MINNESOTA,

Document #120-86-414 for Minnesota Pollution

Control Agency, June 25,1986.

Valine, S.B., TJ. Chresand and D.D. Chilcote, SOIL

WASHING SYSTEM FOR USE AT WOOD PRESERVING SITES, Proceedings of the 1989 Air and

Waste Management Association/USEPA International

Symposium, p. 257-268, Feb. 20-23,1989, Air and

Waste Management Association, 1989, Pittsburgh,

PA.

Wilson, S., THE IMPORTANCE OF BIOREMEDIATION, Pollution Equipment News, Dec. 1989, p. 67

ffd.

16
Appendix A

Process Description

Introduction

This section of the report presents a concise description

of the process as it was carried out at the MacGillis and Gibbs

site. Predemonstration factors involved in site selection are

presented to assist engineers and scientists in evaluating the

suitability of the process for their own needs at Superfund and

other hazardous waste sites. Results of the demonstration,

including a summary of analytical test results, are presented in

Appendix C.

Brief reference is also made in this Appendix to two

parallel studies that were also carried out in conjunction with

the evaluation of the biological treatment process. These were

the BioTrol soil washing study and the Westinghouse field

immunoassay methodology for pentachlorophenol monitoring. Both of these subjects will be presented fully in independent SITE Program reports.

Process Description

Biological treatment has been widely used for many

years in the treatment of industrial and municipal wastewaters, with aerobic treatment being the most widely used technology. However, as industrial products have been developed

to provide resistance to degradation by the environment, it has

often been assumed that these chemicals also would be resistant to conventional biodegradation. Of specific concern has

been the resistance of chlorinated organics to biodegradation.

It has now been confirmed that using proper procedures and

with development of suitable biological populations, efficient

biodegradation of many organic chemicals, including chlorinated aromatics such as pentachlorophenol, can be achieved.

To provide the most efficient and cost effective treatment

of wastewaters containing such contaminants, BioTrol, Inc.

has developed and applied for a patent for a process called

amended fixed-film aerobic treatment. In this technique an

initial biogrowth is developed on an inert support matrix such

as corrugated polyvinyl chloride sheets (Figure A-l) using an

indigenous bacterial source. The initial bacterial population,

having come from the local soil, has developed some resistance to the toxicity of the local contaminants and has developed a population distribution which favors the destruction of

such chemicals. After this bacterial source has been allowed

to grow and establish itself on the matrix in the presence of

nutrients and a less toxic wastewater, an inoculum of a bacterium specific to the target chemical, pentachlorophenol in this

case, may be added and further acclimation is allowed to

occur using the subject wastewater in a total recycle mode.

The system is then ready for once-through treatment of the

groundwater.

The design of the BioTrol system allows the development

of the largest concentration or population of bacteria capable

of degrading pentachlorophenol in the first chamber, where

the concentration is highest. As the wastewater flows through

the reactor and the pentachlorophenol concentration diminishes, other bacteria more suitable to degradation of other

contaminants, but perhaps more sensitive to deactivation by

pentachlorophenol, have the opportunity to grow and consume those contaminants.

The BioTrol system used in this demonstration consists

of a single mobile trailer (20 ft) on which all the vessels,

pumps, etc. for the entire process are installed (Figure A-2). A

level area (ideally a concrete apron) about 50 x 50 ft is needed

to support the trailer and auxiliary facilities. The hydraulic

capacity is about 10 gpm. Contaminated water from any

source is brought to a mixing or conditioning tank where the

pH is automatically adjusted as necessary to just above 7.0 by

metering in a 50% caustic solution. A solution of nitrogen and

phosphorus nutrients (urea plus trisodium phosphate) is also

metered in at a predetermined rate. The mixed water is passed

through a heat exchanger and then through a heater to elevate

the temperature to about 70’F (2l’C) before it is introduced

into a 3-cell biological reactor (Figure A-3). As shown in

Figure A-4, influent is introduced into the base of each

chamber by means of an underflow weir. Air is simultaneously pumped to the base of each chamber and distributed

by a network of sparger tubes to maintain sufficient dissolved

oxygen (about 5 ppm). The combination of the flow, the air

sparging, and the design of the plastic media are such that

upward and lateral distribution of the water and the air occur

in each chamber. After moving through the three chambers,

the effluent exits at an overflow weir from the third chamber.

While the process is claimed to be relatively insensitive

to suspended solids and dispersed oil and does not incorporate

means of removing these contaminants, the vendor recognizes

and is ready to incorporate oil/water separation or solids

removal as necessary, depending on the wastewater being

treated. In the case of the MacGillis and Gibbs site, no such

pretreatment was deemed necessary.

Similarly, while BioTrol’s experience has been that posttreatments such as suspended solids removal or carbon polish17
ing are not always necessary, EPA made the decision that a

small bag filter and a carbon adsorber would be added to the

effluent line to assure the safety of the discharge to the

Minneapolis Metropolitan POTW. EPA also chose to install a

carbon adsorber on the air exhaust line exiting from the

bioreactor to assure that no hazardous volatile chemicals were

discharged. Analyses were carried out before and after both

carbon adsorbers as part of the demonstration program to

assess the need for such protective devices at future sites.

BioTrol Soil Washing Process

In addition to the Aqueous Treatment System, Biotrol

also has developed a soil washing process that separates large,

relatively uncontaminated sand from more heavily contaminated fine material such as clay. PCP contamination of the

fines is then reduced by biological treatment in a slurry

bioreactor. The relatively clean sand and even the slurryreactor treated clay may then be returned to the site. The

BATS is employed in this sequence to treat the washwater

used to separate the sand and fine materials. The Soil Washing

process is the subject of a separate SITE demonstration pro

gram at the MacGillis and Gibbs site and is being reported

separately.

Field Immunoassay for Pentachlorophenol

While the background for this project was being developed, EPA’s Environmental Monitoring Systems Laboratory

(EMSL) in Las Vegas was searching for a facility where a

Blocks new field method for monitoring pentachlorophenol in wasteCross-stacked waters could be studied under real-world conditions. The

BioTrol demonstration project at the MacGillis and Gibbs site

Figure A-1. Corrugated polyvinyl chloride media. was an ideal environment to evaluate this technique in parallel

with the extensive analyses being done as part of the demonstration. Consequently, arrangements were made to have EPA’s

contractor personnel carry out field tests of this method as part

of their assignment.

L Caustic

\\

L Heater L Reactor

Blower

L Temper Tank

Figure A-2. BioTrol, Inc.‘s mobile aqueous treatment system.

18
The test itself, developed by Westinghouse, takes advantage of the inhibition of bacterial enzyme activity that occurs

when a target chemical, in this case pentachlorophenol, is

present. The inhibition is observed by a color change in a

reagent matrix and is readily quantified using standards. Only

very small samples of material are needed and the results are

generated within an hour. The field evaluation sought to

determine the sensitivity of the test in real-world wastewater

matrices, its convenience and reliability in the field when used

lnfluent Heat

Recovery Effluent

n to POTW

e

w .

*ir ..._. ..-_,._._ I *...a.. I

j.. -- _a.-

._.-.

Figure A-3. Schematic of BATS system.

by relatively inexperienced personnel and, most important,

how well results correlated with the standard GC/MS analysis

and larger scale laboratory immunoassays.

Reference is included to make the reader aware of this

effort and the potential availability of the method. A report

documenting the procedure, equipment, and results of this

study will be available under the SITE program.

Figure A-4. Schematic of bioreactor.
Appendix B

Vendor’s Claims

Introduction

The technology developed by BioTrol for treatment of

wastewaters involves the use of naturally occurring microorganisms for the destruction of dissolved organic contaminants. Since the early 1900s biological treatment has been

utilized for the treatment of municipal wastewaters, and has

long been recognized as a low cost, highly effective technique

for the destruction of organic compounds. Only recently,

however, have the microbial pathways for the biodegradation

of widespread priority pollutants been elucidated to the point

where effective treatment systems can be applied. Using

naturally occurring microbial systems, the effluent produced

by this technology is substantially reduced in concentrations

of many hazardous compounds, including PCP, polynuclear

aromatic hydrocarbons (PAHs), gasoline components (BTEX),

solvents, and substituted phenols. Removal efficiencies for

these compounds in the 95 to 99 percent range have been

achieved by BioTrol in on-site demonstrations and full-scale

installations. Concomitant reductions in biochemical oxygen

demand (ROD) in the 75 to 90 percent range have also been

achieved.

While there are several treatment methods for removing

organic compounds by chemical oxidation-such as UV/

ozone, chlorine dioxide, or hydrogen peroxide systemsthese methods often incur very high operating costs (due to

quantity of oxidant required) when applied to wastewaters.

Furthermore, the complete conversion of the organics to carbon dioxide and water is often not achieved. On the other

hand, separation techniques, like carbon adsorption, merely

transfer the contaminants to another medium (the adsorbent)

which must then be regenerated, often at a very high expense.

Biodegradation offers the potential to completely mineralize the organic contaminants with little or no consequential

risk to the environment, at a much lower cost than that of

systems utilizing chemical oxidation or adsorption. In addition, biological treatment efficiently removes organics contributing to the BOD of the wastewater, thereby reducing

sanitary sewer surcharges, or even rendering the effluent

suitable for stream discharge. In cases where carbon adsorption is required as a post-treatment, the removal of BOD

serves to greatly reduce the cost of carbon usage.

Technology Description

Reactor Design

Reactor design is critical to successful implementation of

this technology. BioTrol employs a multi-stage, submerged,

aerated, fixed-film reactor that provides a high biomass concentration and, consequently, a reduced reactor volume. This

is known as the BioTrol Aqueous Treatment System or BATS.

The multiple stages create a dispersed plug flow of wastewater through the reactor. The plug flow configuration is important in that contaminant concentrations typically fall in the

range of first order removal kinetics. That is, the rate of

removal is proportional to the concentration of contaminant.

A completely mixed tank system operating at a low effluent

concentration will experience low removal rates. A system

with plug flow characteristics, on the other hand, will experience the same low rates in the effluent sections; however, the

influent sections will operate at very high rates, thus yielding

higher overall removal rates than the mixed tank system.

The use of a fixed-film system allows for a long cell

retention time and, therefore, lowered production of excess

sloughed biomass. Moreover, the fixed-film system eliminates the often problematic biomass separation step which is

crucial to successful operation of an activated sludge system.

The BATS can be skid-mounted and fully automated to allow

for minimal operator attention.

Microbial Amendment

Many of the priority pollutants can be degraded by microorganisms indigenous to a given wastewater. For these compounds, treatment can be accomplished by simply adding the

appropriate inorganic nutrients and allowing time for acclimation. However, in cases where a highly toxic or recalcitrant

compound is to be treated, the appropriate microorganisms

may be absent. In these cases, treatment can be accomplished

by adding organisms with the appropriate degradative capabilities. This technique, called microbial amendment, is finding increasing use as microbiologists continue to isolate

organisms with novel metabolic pathways.

As an example of microbial amendment, a Flavobacterium

species is used by BioTrol for treatment of pentachlorophenol-contaminated wastewaters. This microorganism can perform rapid mineralization

concentrations up to 200 mg/L.

of pentachlorophenol at

20
Applicability

The following is a partial listing of organic contaminants

which can be successfully biodegraded:

420 lb COD/1000 ft3 packed volume/day). The continuous

flow bench-scale study, in this case, was used to generate

design data for a full-scale system.

Pesticides Solvent-Contaminated Process Water

2,4-D, pentachlorophenol, dieldrin, parathion,

2,4,5-T, formaldehyde, aldrin, malathion,

low-MW polynuclear aromatics

Solvents

acetone, methyl isobutyl ketone, methylene

chloride, acetonitrile, methyl ethyl ketone,

cyclohexanone, ethyl ether, methanol, cresols,

trichloroethylene and related compounds

Table B-l shows the results of another continuous flow

bench-scale study involving treatment of solvent-contaminated process water. The target compounds in this case were

methyl ethyl ketone, toluene, and tetrahydrofuran. These removal percentages were achieved at a loading rate of 110 lb

COD/1000 ft.’ packed volume/day and with an influent COD

concentration of about 3000 mg/L. In this case, treatment was

accomplished solely by microorganisms indigenous to the

water.

Petrochemicals

benzene, ethylbenzene, toluene, xylene,

alkanes, styrene, tetrahydrofuran, alkenes,

diethyl phthalate

Influent, ppb

I

Effluent, ppb

1

Chemical Products

aniline, ethylene glycol, chlorobenzene,

benzidine, substituted phenols, ethyl acetate,

hexachlorobenzene, acrylamide

Case Studies

Biodegradation has wide applicability for the treatment

of wastewaters contaminated with various toxic organics. In

fact, treatment of PCP represents a “worst case” in that PCP is

one of the most highly toxic of the common priority pollutants. BioTrol has also had success treating a variety of other

wastewaters with the BATS approach. These waters range

from very high strength process water with high concentrations of substituted phenols to low strength groundwater

contaminated with trace concentrations of benzene.

5000

4000

3000

2000

1000

0 1 1 ,

BTEX-Contaminated Groundwater

0 5 10 15 20 25

Days

Figure B-l shows the performance of a full-scale BATS

unit treating gasoline-contaminated gtoundwater (benzene,

toluene, ethylbenzene, and xylenes as primary contaminants)

at 15 gpm. This system has consistently performed >99 percent removal of benzene since installation, and the effluent

qualifies for discharge without a polishing step. This system

will ultimately be coupled with an in situ treatment process at

the site. Effluent from the reactor will be amended with

hydrogen peroxide and reinjected into the aquifer to initiate

treatment of the soil.

Figure B-l. Benzene treatment by BATS.

Phenol-Contaminated Process Water

Figure B-2 shows the performance of a bench-scale BATS

system for continuous treatment of a process water from a

creosoting operation. The target contaminants in this case

were substituted phenols. Percent removal of total recoverable

phenols remained high even at very high loading rates (up to

Table B-l. Treatment of Solvent-Contaminated Process

Water

t %

4.3 ~~~~

40

30

20

10

0

21
Summary

The BATS technology demonstrated under the SITE

Percent Removal

100

program has wide applicability for treatment of contaminated

groundwaters and process waters. Many contaminants are

amenable to biodegradation by indigenous microorganisms,

and in some cases, microbial amendment can be used to

promote biodegradation of recalcitrant compounds. The BATS

can achieve high removal efficiencies at relatively high organic loading rates. Contaminants amenable to treatment include pentachlorophenol, gasoline components (BTEX),

solvents, PAHs, and substituted phenols. Table B-2 summarizes results of laboratory, pilot-scale, and commercial trials

of the system.

80

60

40

20

0

0 100 200 300 400

Loading (lb COD/1000 cf/day)

500

Figure B-2. Phenols removal by BATS.

22
Table B-2. BATS Performance Data

Description Scope Contaminants In fluent Effluent Removal

(Was te/Loc.) mg/L mg/L %

Wood preserv. lab COD 1700 60 96

(GA) treat

DOE Mfg site lab

Iti) treat

Total K001 70

TCE 10

vinyl chloride 3

DCE 10

PAH 10

COD 100

total phenols 2

PAHs 1.2

COD 2000

total phenols 6.3

COD 15000

1.3

0.05

cimo5

dwo5

2

70

0.6

0.02

300

0.8

1800

98

99

>99

>99

80

30

70

98

85

8 7

88

43 3 93

PCP

COD

PCP

total phenols

COD

MEK

THF

Cydohexanone

COD

PCP

total phenols

COD

BTEX

4.5

11000

70-80

10-50

5500

40-50

5-10

3100

9-10

5-6

800-850

5- 10

4.5

2500

0.2-0.5

<0.5

600

0.005

0.02

0.02

730

0.03-0.5

0.6

300-350

<0.08

99

77

99

>95

89

>99

>99

7s

>94

>88

fi6

>98

Total PAHs

COD

PCP

Total phenols

COD

PCP

BTEX

total phenols

COD

PCP

TOC

PCP

BTEX

BTEX

90-100

10-13

250-300

10-15

50

l0-11000

2-5

1

20-200

500- 1500

40-45

80

90-100

7-8

3-5

0.5-2

0.5 -1

150-200

0.2-0.5

20-30

5-6000

0.03-0.5

<0.01

l-5

200-800

0.1-l

50

<0.5

0.1-0.2

<0.01

total phenols 50-150 l-5 >90

total PAHs 5-6 0.3 >94

Wood preserv. lab

(GA) treat

Wood preserv lab

(AL) treat

Wood preserv. lab

(GA) treat

Wood preserv. lab

(AK) treat

Wood preserv. lab

(GA) treat

Wood preserv. bench

(TX) cont

Tape mfg. bench

(CA) cont

Wood preserv. bench

(Canada) cont

Gas Station

(MN)

Woodpreserv.

(MN)

pilot

Wood preserv.

(GA)

pilot

window mfg.

(WI)

Wood preserv.

(TX)

Wood preserv

(MN)

window mfg.

(IA)

Gas Station

(MN)

Wood preserv.

fV

pilot

pilot

(. 75 9P’

23
Appendix C

SITE Demonstration Results

Introduction

The goal of this demonstration project was to study the

effectiveness of the BioTrol ATS in removing PCP and PAHs

from wood treating wastewaters. After considering another

site, the MacGillis and Gibbs site in New Brighton, MN

became the prime candidate on the basis of the Remedial

Investigation/Feasibility Study (RI/FS) that led in its inclusion on the National Priorities List in 1984. The RI/FS study

suggested that the groundwater under the site could be heavily

contaminated with both target species. In addition, BioTrol,

Inc. had already treated process water contaminated with

pentachlorophenol in conjunction with its soil washing unit at

the facility.

The MacGillis and Gibbs Company site had been used for

wood treatment since the early 1940s. Creosote was the

preservative until the mid-1950s when a shift was made to

pentachlorophenol in a light oil. Impregnation was carried out

in open troughs, resulting in significant spills and drippage. In

addition, the pentachlorophenol/oil mixture occasionally was

used for weed control throughout the site. In the 1970s,

pentachlorophenol was replaced by the newer chromated copper arsenate process and enclosed pressure kettles were substituted for the open troughs, thereby eliminating many of the

sources of contamination.

An adjacent facility, the Bell Pole and Lumber Company,

also was treating wood during the same period. While it is still

unconfirmed, there may be movement of contaminated groundwater from the Bell site to the MacGillis and Gibbs site. A

disposal area in the western portion of the MacGillis and

Gibbs site also may be a source of soil and groundwater

contamination. Figure C-l presents the general layout of the

facility and the location of two wells that were drilled to

assess the suitability of the site for the SITE demonstration

project.

While the RI/FS sampling results suggested that there

were pockets of creosote and pentachlorophenol contamination as a result of operations dating back to the 194Os, there

were no groundwater test well results to assure that an appropriate wastewater (sufficient flow, suitable levels of pentachlorophenol) would be available for the demonstration.

Therefore, two wells were drilled in locations based on the RI./

FS reports (Figure C-2). During the drilling, rapid tests for

pentachlorophenol (PCP) were carried out at increasing depths

using the High Pressure Liquid Chromatography (HPLC)

method devised by BioTrol. lData in the QA comparison

study conducted as part of the QA program confirmed that

BioTrol’s HPLC data are comparable to data from EPA’s

SW-846 Method 8270.] The first of the two wells contained

about 45 mg/L of PCP, adequate for the demonstration (although a higher level would have been preferred) and was of

adequate flow (>5 gpm) for the demonstration project. This

well was fully developed by pumping for about 69 hours;

further PCP analyses at about 10 hour intervals (by HPLC)

confirmed the 45 mg/L range. The second well, located about

65 feet away, contained an unacceptably high level of oil (a

lens of oil), significantly lower PCP levels, and inadequate

flow when subjected to a pump test of flow (Table C-l).

Upon consideration of the BioTrol process and the groundwater available, it was determined that the key variable that

could be tested was flow rate. At a constant concentration, this

allowed the capacity of the system in terms of pentachlorophenol removal to be studied. To avoid shock loading and the

need for re-acclimation, the flow rate into the system was

incrementally increased, allowing it to stabilize at each flow

rate so that analytical results of “steady state” operation could

be obtained. Three experimental stages of two week duration,

at 1,3, and 5 gpm flow rate, were selected on the basis of the

capacity of the pilot scale system.

Influent, effluent, and intermediate points in the bioreactor

were sampled by 24-hour composites for PCP or full semivolatile organic scans during each regime. Other constituents

were sampled and analyzed at varying frequencies and locations, including the well, during each experiment using appropriate grab or compositing techniques. Included were oil/

water, total and volatile suspended solids, volatile organics,

nitrogen and phosphorus nutrients, and heavy metals. Chloride and TOC analyses were given particular attention since

changes in these parameters should parallel pentachloropheno1 destruction and establish whether mineralization of the

pentachlorophenol does occur, as claimed by the vendor.

Air leaving the bioreactor was also monitored for volatile

organics and semivolatiles, before and after a carbon adsorber,

to determine whether stripping was a significant contributor to

removal. The Quality Assurance Project Plan also called for

the sludge in the bag filter to be collected and analyzed to

leam if absorption of pentachlorophenol on the biological

growth was a contributor to removal, however, the nature of

the filter and the small amount of sludge produced allowed

only limited analyses. The effluent from the aqueous carbon

adsorber was also analyzed to assure that the discharge met

the 2 mg/L pentachlorophenol limit imposed by the POTW.

24
Bell ;

Pole

I

I

L

I

Figure C-l. MacGillis & Gibbs site.

Field Activities

BioTrol personnel were responsible for acclimating the

system over about a two week period using the selected well

water in a recycle mode. The system was inoculated with a

PCP-specific flavobacterium after one week. EPA contractor

personnel initiated sampling when BioTrol advised EPA that

the system was acclimated. A separate laboratory trailer was

available where contractor personnel could prepare equip

ment and samples, although much of the sample handling was

done outside.

Test Procedures

Composite samples were collected in ice-chilled Isco

samplers for 22 hours. Grab samples were taken on a predetermined schedule using transfer beakers or by direct immersion

of bottles and then were processed in a manner similar to that

for the composite samples. Samples were transferred to bottles,

inhibited or preserved as called for by the individual methods,

labelled, sealed, and shipped in ice-filled coolers to off-site

laboratories by overnight express. Flow was occasionally

measured manually at the well as well by monitoring readings

from a flowmeter on the effluent line. The temperature, dissolved oxygen, and pH in the three chambers of the bioreactor

and the groundwater were also documented to assure that no

gross change in conditions affected reaction effectiveness.

Sampling points are indicated on the schematic of the system,

Figure C-3. The sampling schedule, analytical protocols used

and results, and QA/QC protocols are described in the Technology Evaluation Report. The ongoing QA program allowed

for the collection and reporting of high quality data

25
Table C-1. Analyses of Wells on MacGillis and Gibbs Site

.___.___ . ^.

I

2

.^. . ;by HPLC during 69 hr well pump test - ~- ” b by HPLC after development, well not “pump tested

Figure C-2. Well construction.

26
Figure C-3. BioTrol aqueous treatment system (BATS) with sampling points shown.

With the exception of an inoperative dissolved oxygen

meter at the outset of the project, all process and sampling

equipment functioned well. The design of the reactor and the

mobile trailer is such that space was very limited and some

improvisation was necessary in collecting certain samples.

Air monitoring of the exhaust stack from the bioreactor

before and after the carbon adsorber used a modified MM5

stack method and XAD adsorbent resin traps. Modifications

were necessary when determining air flow through the system, because of the narrow diameter of the stack (3-4 inches).

These tests were carried out about once per week for three

weeks.

The sludge in the bag filter could not be readily, consistently, nor completely removed from the bag. Eventually, the

bag was removed at arbitrary times and cut up so that solids

could be flushed from the fabric for sampling purposes.

Results

System Parameters

Nitrogen as nitrate, nitrite, and ammonia, and phosphorus

as phosphate were monitored over the course of the investigation. No unusual effects were observed; the presence of residual nutrients in the effluents suggests that reaction

(biodegradation) was not inhibited by insufficient nutrients.

Similarly, dissolved oxygen was measured in each chamber of the reactor twice daily over the course of the study and

found to remain reasonably constant between 5 and 6 mg/L.

There was a slight increase in the dissolved oxygen as the

27
water passed through the system and was aerated by the air

sparger system. The incoming groundwater contained <1.0

mg/L dissolved oxygen.

Some variation in temperature was observed throughout

the project (Table C-2). The temperature of the influent to the

bioreactor was lower in the 3 gpm (14-17 C) and the 5 gpm

(14-21 C) studies than in the 1 gpm study (22-25 C). This

probably was partially due to a decrease in the temperature of

the groundwater over the course of the program, and possibly

also due to inadequate heat exchange to the incoming groundwater, which was at a lower temperature (11 - 16 C). The

heater was not used. As expected, temperature increased

slightly as the wastewater passed through the system, i.e., the

effluent temperature was higher than the influent temperature

in all three study segments.

Table C-2. Temperature Across Blo Trol System

Flow Gdwater

(gpm) #1

Temperature PC, avg)

lnfluent Midpt Midpt Effluent

#2 #3 #4 #5

1 21 23.4 24.6 24.5 24.6

:

11 15.7 20.4 20.9

13 14.6 20.6 ZI 20.9

While vendor specifications called for a pH of about 7.3

in the tempering (conditioning) tank, the pH measured in the

three chambers of the bioreactor usually was somewhat higher,

particularly at the lower flows and, at least at the 1 gpm flow,

appeared to increase across the system. The pH of the groundwater was consistently in the range of 6.7-6.9 standard units.

Initial oil and grease values of approximately 50 mg/L

were reduced to <10mg/L by passage through the system.

Total suspended solids levels (TSS) in the incoming well

water were quite low (<5 mg/L) and increased (to 54 mg/L at

1 gpm, 26 mg/L at 3 gpm, and 18 mg/L at 5 gpm) over the

course of the study (Table C-4). At these levels, the suspended

solids (sloughed biomass) probably do not represent a significant mechanism for removal of organic pollutants. Volatile

suspended solids represent approximately 40% of the total

suspended solids in the effluent, increasing slightly (to -50%)

at the highest flow rate.

Pentachlorophenol Removal

With the receipt of the first PCP analytical data generated

by SW-846, Method 8270, it became clear that the anticipated

results were not being obtained. Influent PCP values (composite samples) were significantly lower than the concentration at the well (grab samples). Analyses by BioTrol using

grab samples just before the bioreactor (Point “B” in Figure

C-3) and the HPLC method agreed with the higher well data.

At first it was thought that the difference might have been due

to foaming during the extractions for the analytical procedure

(SW846 Methods 3510/8270). While that problem persisted

throughout the study and did affect the recovery achievable

for the samples, it became clear that it was not the cause of the

drastic differences between the well or BioTrol’s samples and

the influent chamber samples.

Additional QA testing indicated that BioTrol’s HPLC

method for PCP and EPA’s Standard Method (SW-846, Method

8270) are comparable when extraction efficiency is taken into

account. This information aided in establishing that the well

water concentrations of PCP were actually better representations of the influent concentrations than the influent data by

the SW-846 method. Consequently, removal efficiency determinations (Table C-4) were based on well water and effluent

data (both by Method 8270) instead of the influent samples.

Other possible explanations for the anomaly in results

were then considered, including absorption on the walls of the

bioreactor, separation of a PCP-in-oil layer, and backmixing

under the underflow weirs separating the chambers.

Backmixing appears to be the best explanation for the low

values obtained for the influent and the gradual improvement

in agreement between well water data, BioTrol HPLC data,

and influent data as the flow rate was increased each two

weeks. Well water (sampling point #l) and influent (sampling

point #2) PCP values in Table C-4 are much more in agreement at the 5 gpm flow than at the 1 or 3 gpm rates, suggesting

that the importance of the backmixing decreases as the flow

increases.

Grab samples also were taken from a "T" just before the

influent chamber (point B on Figure C-3) and analyzed by

BioTrol’s HPLC method. These samples, which were not

subject to the backmixing, agreed with the well samples

(sampling point #l). Consequently, the grab samples from the

well were primarily used in determining PCP removal. Within

limits discussed later, free chloride and TOC data at the

several sampling points also support this conclusion.

On the assumption that the correct concentration of PCP

in the influent was about 45 mg/L in the 1 gpm study but was

about 7 mg/L in the first chamber of the bioreactor, it was

estimated that approximately 5 gallons was “leaking” back

through the system for every gallon introduced.

Nevertheless, using either the well water or sampling

point #l, it is clear that the BioTrol Aqueous Treatment

System does effectively remove PCP from the groundwater as

it moves through the system. Concentrations of PCP after

treatment (but before carbon polishing) were about 0.13 mg/L

at the 1 gpm flow rate and increased to an average of 0.99kO.49

mg/L at the 5 gpm flow rate.

The BATS achieves at least 95% PCP removal at the 5

gpm flow rate and 99% at the lower flow rates. Even using the

lower influent chamber analytical results (#2), percent removal is still excellent,

Based on the estimated mass of PCP introduced to the

system over each two week experimental period, and assuming that all PCP is lost by biological degradation, mass removals of >95% are consistently achievable (Table C-5).

28
5 .6 x5.7* 22.51: 9.5 .o?r 2. _ .~_ __“_ ^. ^ ._. _.^ ...I^ ^^. “- ..- “__. ,. -..~ll”-.““l - “^^ “_ _...” _. - .._.._ Note:Complete data can be found in the Technology Evaluation Report.

--.” -“^.“l.l . .._. ^... “_^ . .^ “I _ ^^.. ..___ _.. ._ ._._.

Table C-4. Average Pentachlorophenol Removal by BioTrol System

_..____.__ _.,_~ _.... ___^__. ._ “^..“_ ^--._-^^I-Ix-.^..I--I I-I__..___ ___ __ ._.. ____._-_.~..” ..__ __. “. ^ .^. .“. __““. - _.“.^ ^._..‘....‘” _.__”

l The gradual decrease in groundwater concentration may be a result of well drawdown over the 6 weeks of operation.

Comparison of analytical results for PCP in as-is samples

and in filtered samples indicated that very little if any of the

PCP was absorbed on the filterable solids. While there were

measurable concentrations of PCP in the sludge samples, the

amount of sludge exiting the bioreactor was so small that this

is not considered a significant contributor to the removal of

PCP from the system. Similarly, the low concentration of oil

in the effluent (<10mg/L) strongly argues against loss of PCP

by extraction into that phase. Analyses of the air exhausted

from the bioreactor confirmed that no detectable quantities of

pentachlorophenol were lost by this route.

Table C-5. Mass Removal of Pentachlorophenol

8%

~~~~~

l Based on well water (#1) analyses

Chloride and TOC monitoring of the groundwater and

the effluent produced results that are consistent with the

vendor’s claim that the pentachlorophenol is mineralized,

but indicate that other contributors to chloride and TOC are

present. Table C-6 summarizes the actual changes in chloride and TOC and the changes calculated on the basis of the

observed decrease in pentachlorophenol.

Removal of other organic constituents, even including

oil or biomass, may explain why the observed decreases in

TOC levels are greater than calculated. The concentrations

of mono-, di-, and trichlorophenols (by SW846 Method

8270) all were below the detection limits in the semivolatile

scans of the groundwater, influent, and effluent; however,

the detection limits were often quite high since pentachlorophenol was the primary “target” of the analyses. It is also

reported that commercial pentachlorophenol may contain as

much as 20% by weight of tetrachlorophenols (TCPs). If, for

example, the PCP were accompanied by 20% by weight as

tetrachlorophenols (which were not target analytes), this

would mean 8.4 mg/L of TCPs were present and could

contribute 5.1 mg/L of chloride. [Review of two archived

scans of groundwater indicated total TCP contents of about

4% and 10% of the PCP concentrations.] And, if all the

partially chlorinated isomers (mono-, di-, and

trichlorophenols) were present at just below their detection

limits in the well water sample, they could contribute an

additional 6.4 mg/L of chloride. Table C-7 summarizes the

calculated chloride yields during the 1 gpm study.

Polynuclear Aromatic Hydrocarbon Removal

Concentrations of the various PAHs in the incoming well

water were lower than anticipated and below the detection

limits. The high detection limits for PAHs in the semivolatile

organics GC/MS scans, often in the range of 2 mg/L when

analyzing for PCP in the 10-50 mg/L range, precluded measurements at pg/L level. Two values for total PAHs obtained

during the predemonstration well drilling effort, 145 and 295

mg/L, are consistent with the absence of PAHs at the indicated detection limits during the project. The lack of specific

values for PAHs in the well water and/or the influent makes it

impossible to assess the removal of these chemicals across the

system. Specific PAHs also were not measurable in the effluents even though the detection limits were now 10-100 p@L.

In other studies by BioTrol it was demonstrated that PAHs are

removed by the BATS (see Appendix D). Limited analyses on

a few sludge samples for PCP or PAHs indicated detectable

quantities of selected PAH compounds, as noted in Table C-8.

Because of the small amount of sludge discharged, accumula29
tion of PAHs (or PCP) in the sludge is not a significant

contributing mechanism for the removal of these species.

Monitoring of the reactor exhaust air, before and after the

carbon adsorber, indicated that some stripping of polynuclear

aromatic hydrocarbons does occur, probably due to the air

bubbled through system (Table C-9). Additional air was also

introduced to the stack during the monitoring, which may

explain the observation that some naphthalene did pass through

the carbon, possibly by an air “regeneration” phenomenon.

Small amounts (=< 1 pg/L) of phenol, 2,4dimethyl phenol,

and other, higher molecular weight PAHs (dibenzofuran and

fluorene) also were found occasionally in the pre-carbon

samples but not in the after-carbon samples.

Polychlorinated Dibenzo-p-Dioxinsl

Dibenzofurans

Selected samples were scanned for the various dioxins

and furans using high resolution GC coupled with low resolution MS. A number of the chlorodioxin and furan species were

found to be present in the influent and the effluent, usually at

the nanogram/liter level. The 2,3,7,8-TCDD isomer was reported at above detection limit in only one sample (62 ng/L in

an effluent sample). Review of the data (Table C-10) also

indicates an increase in concentration for all the isomers as the

wastewater moves through the reactor, possibly due to accumulation of dioxins on the biomass, which does increase

across the system and is sloughed off into the effluent.

Table C-11 presents dioxin/furan data for the sludges

collected in the bag filter during the study. Some dioxin/furan

isomers were found in the sludge, in the ng/gm range based on

wet weights. This is not considered a problem in light of the

small amount of sludge generated, except that the sludge may

require disposal as a dioxin-contaminated material.

Heavy Metals

While arsenic and various heavy metals were found in the

groundwater at low concentrations, these constituents pass

through the system with little change in concentrations (Table

C-12)-with the exception of the first effluent sample, which

shows anomalous results

Volatile Organics

Analyses for volatile organics indicated that few of these

materials were present in the groundwater, even at low concentrations. Levels were further reduced by passage through

the treatment system, probably by stripping. Volatile organics

were not detected in the exhaust air collected from the reactor.

Biomonitoring

Biomonitoring with two different species, minnows and

water fleas, was carried out on the groundwater, the influent,

and the effluent. The results confirmed that the groundwater

was toxic to these species and that treatment removed the

cause of the toxicity. The results in Table C-13, presented as

LC(50) values, reflect the percentage of groundwater, influent, or effluent in the water that could be tolerated in the test

water before 50% of the species succumbed. When 1% or

even less of either the groundwater or the influent is incorporated in the test water, 50% or more of the test species die

during the test period. After treatment, the effluent has essentially no adverse effect on either species during the test period,

even when 100% effluent is the test water.

Table C-6. Comparison of Chloride and TOC Changes with PCP Removal

~~~~~~~ CI( ‘~~~~~~~~

IFI

.“...” _ I .^_. ~ I^_ ___._._._____ +

+

* -7.0

Table C-7. Potential Chloride Contributions from Partially Chlorinated Phenols

_ _ ..‘. “._..^_.._^_

..- _ __..___.... -._. _ __.

30
Table C-9. PAHs in Air Emissions from Bioreactor

SX

T ““l”ll,.__ ...l” .,.., _ _.... Il,l~“__x”I ,___ 1 .._ I-. _._^^^__. -__-____ _ ______.__ ___.__..._ .____ ._ “.__

I 1

2 I

3 1 3.7

3

5 5 ^. ” . _..._ _.. ._ I

Table C-10. Dioxins/Furans Found in System

Influent/Effluent Concentrations

(ng/L)

31
Table C- 11. Dioxins/Furans Found in Sludge

Table C-12. Metals Found In System

ek

_ ____._-” _____l_.__ “.. ..- . ..- ^^ --.”

cu a P 2-n

Table C-13. Acute Biotoxicity of Groundwater and Treated Effluent

32
Appendix D-l

Full Scale Wood Preserving Site

Introduction

The subject of this study is a wood preserving facility

using the Boultonizing process that generates a process water

contaminated with creosote-derived phenolics, polynuclear

aromatic hydrocarbons (PAHs), and aromatic compounds extracted from the wood. The BATS unit offered an opportunity

to treat this wastewater biologically in a compact, efficient

manner with minimal operator attention.

The process water to be treated contains significant oily

material. It is treated in two stages for oil/water separation and

then cooled in a cooling tower. Water from the cooling tower,

which was previously discharged to an on-site lagoon, was

treated in the pilot study and, subsequently, in the commercial

unit. The character of the feedwater varied considerably,

depending on the type of wood treated, rainfall, and evaporation rates (Table D-l).

Table D-1. Characteristics of Phenolic Process Water

Constituent Average Range

(mg/L) (mg/L)

Phenols 129 11-327

SCOD 1059 412-1912

SOD 752 75 1200

TSS 104 22-659

Oil/grease 28 8-270

pH 6-9

Temperature (F) 80-90

Pilot Scale Studies

A pilot scale demonstration study using a 3-celled mobile

unit with a 15 gpm flow capacity was carried out over six

weeks at flow rates of 2 gpm and 1 gpm. Influent and effluent

samples were collected daily as 24-hour composites while the

bioreactor cells were grab-sampled. Key analyses were total

recoverable phenolics (TRP) by Standard Method 510.B and

chemical oxygen demand (COD) by the 01 Corp. method. In

addition, biochemical oxygen demand (BOD), oil and grease,

and total suspended solids (TSS) were also analyzed. On three

occasions during the course of the pilot demonstration, samples

were analyzed by EPA Method 610 for polyndclear aromatic

hydrocarbons (PAHs).

Based on analytical results from a pilot unit (Figure D-l),

effluent concentrations of phenols were almost always below

1 mg/L, corresponding to an average phenolics removal of

>99%. Decreases in BOD and COD, while significant, were

not as great, possibly due to sloughed biomass. Variations in

TSS indicate a cyclic character to the TSS values, suggests

that solids accumulation occurs followed by solids release.

PAH removal was in the range of 80+%, but elevated PAH

levels for total samples (including sloughed solids) from the

middle cells suggest that adsorption of PAHs on solids as well

as biodegradation is occurring (Figure D-2).

Commercial System Evaluation

Based on the success of the pilot scale demonstration in

removing phenolics from the aqueous wastewater, a commercial (30 gpm) unit was installed in August 1988. After a two

week acclimation period (no specific bacterium was added),

the unit has been in continuous operation with the flow rate

starting at 20 gpm and then increased to the design rate of 30

gpm. The effluent is discharged to a POTW. Based on the

results for the first 5 months of operation (Table D-2), the

system has produced effluent with an average phenolics concentration below 1 mg/L with minimal operator attention.

Table D-2. Wood Preserving Wastewater Treatment by BATS

Month Phenolics in Effluent (mg/L)

August 0.12

September 0.058

October 0.14

November 0.20

December 1.11

5 Month Average: 0.33

Cost Data

Operating cost data were developed on the basis of operation of the commercial unit. Assuming a 30 gpm flow rate and

an influent with 1000 mg/L of BOD and 200 mg/L of phenols,

the operating costs were as shown in Table D-3.

Conclusions

Based on the pilot scale studies and operation of the

commercial unit for several months, the BATS is a cost33
effective means of removing phenolics and PAHs from this Table D-3 Operating Cost for BATS Commercial Unit

wastewater.

Cost Item

The nature of the BATS system is such that it requires a ~~~~~~~~~~~~~~~~-“~“~“““~ “~l___“l__l___““-_~“__“_“--~“_~~”~”_”- * __

minimum of labor relative to conventional activated sludge Nutrients (@ $0.71/gallon)

systems where trained personnel may be needed to assure that Labor f KJ k&k @ $15/hr)

optimum sludge separation and return is carried out. Total

-ll*~~__ll”*-*~**~-““~~““~~-““““””””~.”~ ““11”*““*1.“~11~~““*11”“~~11~“11*1”””””1~**.*1***“1*~1* ““““” “” “~11”““*“““1”11 ~“111”“““““1”

260

240

220

200

180

160

100

8 0

6 0

4 0

2 0

0

1 5 2 0 2 5 3 0 35 0 4 5

Days

Figure D-1. Phenolics removal In commercial BATS.

34
30 -

2 8

26 -

24 -

22

20 -

18 -

-

I r

lnfluent Cell 1 Cell 2 Effluent

Location

Figure D-2. PAH removal in commercial BATS.

35
Appendix D-2

Tape Manufacturer

California

Introduction

A tape manufacturing facility in California produces about

15,000 gpd of solvent-contaminated process water. Contributing to a high COD are toluene, xylene, methyl ethyl ketone,

tetrahydrofuran, and cyclohexanone. Currently, the plant uses

activated carbon pretreatment prior to discharge to the POTW.

Biological treatment was considered as an alternate, less

costly treatment.

A bench scale continuous flow evaluation of biological

treatment using the BATS was carried out. Because of high

variability in wastewater loading, the goal of the investigation

was to evaluate the effectiveness of the system at various

organic loadings, in addition to the removal of specific contaminants.

Bench-scale Study

The bench scale continuous flow studies were carried

out using a 55 gallon drum of process water shipped to the

BioTrol facility. The system consisted of a 4 in. ID translucent PVC column packed to a depth of 12 in. with 1 in.

Intalox PVC saddles to simulate the structured PVC packing

used in a commercial unit. Air was injected at the base. The

column was inoculated with activated sludge from a POTW

and acclimated over 10 days. Continuous flow operation was

then maintained for 1 week at each of 3 flow rates: 2,4, and

8 L/day, corresponding to loadings of 110,235 and 485 lb

COD/1000 ft3 of packing/day.

Results

Samples were removed by BioTrol and measured for the

parameters noted in Table D-4 using standard methods.

Biological treatment effectively removed 99% of the

specific components of concern with only slight fall off in

efficiency when the loading rate was increased from 110 to

235 lb/1000 ft’/day. Final effluent with residual concentrations of 5 to 15 pg/L were achieved at the lower loading and

somewhat higher at the higher loading.

The difference between removal efficiency for specific

components and that for COD is consistent with the presence

of other, more recalcitrant constituents. (Other tests indicate

that stripping of volatile organics accounts for less than 10%

of their removal.)

Cost Data

Using the removal data developed in the bench scale

study, cost data were developed for a commercial system with

a 10 gpm capacity. On that basis, the total anticipated operating cost would be $3.51/1000 gallons of wastewater as shown

in Table D-5.

36
Appendix D-3

BATS Treatment of BTEX

Minnesota

Introduction

A truck stop in Minnesota experienced widespread soil

contamination by gasoline from leaking underground storage

tanks. In addition to removing the tanks and highly contaminated soil, it was necessary to treat soil beneath buildings and

groundwater to prevent spread of a contaminated plume.

BioTrol proposed that both goals could be achieved by

above-ground treatment of the groundwater in a BATS, followed by reinjection of the treated water to stimulate in situ

bioremediation of the soil. Laboratory studies demonstrated

that with proper additions of nutrients and oxygen, the indigenous microflora were capable of destroying benzene, toluene, ethyl benzene, and xylenes (BTEX) in the soil to below

detectable levels in 8 days. Since this remediation scheme

depended on initial above-ground treatment to levels suitable

for reinjection, a pilot scale evaluation of the BATS was

deemed to be necessary.

Pilot-Scale BATS

A single column pilot-scale BATS was installed at a gas

station in the Minneapolis area. The reactor column was 1 ft in

diameter and filled to 9-ft depth with 1 in. Intalox PVC

saddles to simulate the structured PVC packing used in the

full scale unit. The system provided 1.6 hr of residence time.

The system was first acclimated for 2 wk with no addition

of bacteria except that in the groundwater. The reactor was

then sampled daily for 1 wk, using composite samples of

influent and effluent taken with a zero headspace sampling

device. Analyses of these samples confirmed that >99% removal of BTEX could be achieved with an influent ranging

from 1900 to 15,000 l&/L, and effluent concentrations of <20

CLgR. for individual components were achieved. The BTEX

results are summarized in Table D-6.

Table D-6. BETX Treatment with the BATS

^__” --_._____ “___l”.l _“^. .^. ^x----I_II.^..- _.., I_ .^___ _^_ _ _.__.^ . “.. I ___ _.___.

Full-Scale BATS

On the basis of the pilot study it was concluded that the

process was very effective at removing BTEX. A two-stage

reactor was installed at the contaminated site to be used in

conjunction with a closed loop groundwater extraction system. Modelling of shallow groundwater flow was used to

design the extraction well and infiltration gallery network.

The BATS is currently treating groundwater at a 15 gpm

flowrate. With a groundwater temperature of 50°F, no heat

input has been found necessary to maintain reactivity. With

influent BTEX concentrations of approximately 4200 pg/L,

consistent reductions to <80 pg/L have been achieved. Measurements of BTEX concentrations in the air exhaust from the

reactor established that air stripping accounts for removal of

only 5 - 10% of the removed BTEX.

Cost Data

The operating and maintenance cost of the combined in

situ and above-ground treatment is expected to average about

$9000/yr. Total cost of remediation, including capital, maintenance and operation, but excluding groundwater monitoring

and project management fees, is approximately $165,000 with

a 3-yr anticipated project life. More detailed information is

not available at this time.

37
Appendix D-4

Pilot Plant BATS

Minnesota

In the fall of 1986, the feasibility of treating contaminated

groundwater at a wood preserving site in Minnesota was

evaluated in a 9-month pilot study using the BioTrol Aqueous

Treatment System. The study was funded by a grant from the

U.S. Geological Survey.

The purpose of the study was to establish the long term

effectiveness of the BATS for such wastewaters, particularly

for the removal of PCP and, secondarily, for PAHs. These

materials are commonly found contaminating sites where

wood preserving operations using PCP and creosote had been

practiced over previous decades. The groundwater at the site

contained 60-100 mg/L of PCP based on preliminary studies.

Pilot Plant Study

A simple 30-gallon packed bed reactor was used in the 9-

month pilot study. The system was activated with indigenous

microflora and later amended with inoculations of a

Flavobacterium specific to PCP. The unit was operated essentially in a continuous mode, over the length of the study,

adjusting pH and adding nutrients as necessary. Air was

continuously injected to maintain aerobic conditions.

BioTrol subsequently developed a proprietary bioreactor

design specifically suited to treatment of contaminated groundwater with an amended, fixed-film microbial system.

Results

The packed bed system effectively removed PCP, PAHs,

and other constituents that were found to be present. The

specific rate of PCP degradation was as high as 70 mg of PCP/

L of reactor volume/hr, well beyond the values normally

reported in the literature. In later work using the proprietary

system design, PCP removal. rates between 40 and 50 mg

PCP/L of reactor volume/hr were consistently achieved, with

rates as high as 65 mg/L/hr being achieved. All PCP analyses

were carried out using a HPLC method developed by BioTrol.

Extensive removal of PAHs was also confiied. While sub

stantial reductions in COD also occurred, the levels in the

effluent indicate the presence of considerable refractory material. Typical results are summarized in Table D-7.

While the influent and effluent data over the 9-month

investigation did exhibit occasional elevated levels in the

effluent, these usually were attributable to mechanical failures, such as loss of aeration, loss of heat, etc. Daily tabulation

of influent and effluent data indicates that the system had

excellent recovery capability after such upsets.

No cost data is available for this small scale study.

38
Table D-7. Groundwater Treatment in 30 gal Packed Reactor

Constituent Well water Effluent Removal

(Ils/L) @gA) (%)

Pentachlorophenol

Acenaphthalene

Naphthalene

Acenaphthene

Phenanthrene

Anthracene

Fluoranthene

Pyrene

Benzo(a)anthracene

Chrysene

Benzo(b) fluoranthene

Benzo(k)fluoranthene

Benzo(a)pyrene

Dibenzo(a, h)an thracene

Benzo(g, h,i)perylene

Fluorene

Indo( 1,2,3-c,d)pyrene

COD (mg/L)

93,000 n d -100

4,402 n d -100

1,932 81 96

2,041 140 93

264 38 86

252 20 92

466 153 67

232 15 94

292 9 96

171 8 95

448 8 98

178 7 96

211 5 98

296 33 89

315 4 99

545 nd -109

203 nd -100

250-300 l00-150 B40

39 ZI U.S. GOVERNMENT PRINTING OFFICE: 1991-551-565