bluuebunny/crossref_metadata_2025 huggingface dataset:
Fly ash recycle in dry scrubbing
Authors: Jozewicz Wojciech , Rochelle Gary T.
Published: February 2007

Previous workers have shown that the recycle of product solids improves the utilization of slaked lime [Ca(OH)2] for SO2 removal by spray dryers with bag filters. In laboratory‐scale experiments with a packed bed reactor, utilization was increased several‐fold when the Ca(OH)2 was first slurried with one of several different fly ashes. The enhancement increased with the higher loading of fly ash [g fly ash/g Ca(OH)2]. Much higher Ca(OH)2 utilization was achieved when silicic acid was used instead of fly ash. Scanning electron microscopy supports the explanation that Ca(OH)2 and silica dissolve and reprecipitate as a more reactive calcium silicate. Other major constituents of fly ash have less or no effect at all on Ca(OH)2 utilization. The amount of calcium in the fly ash did not affect the overall SO2 removal after Ca(OH)2 was added. Slurrying for longer than 2 hours at higher than 60°C can improve the utilization of Ca(OH)2 slurried with fly ash.
The electric utility sulfuric acid plant
Authors: Aragon F. G. , Taylor H. S. , Petrie J. C.
Published: February 2007

San Juan Generating Station is a coal‐fired power plant utilizing the Wellman‐Lord SO2 recovery process for meeting SO2 compliance regulations. A sulfuric acid plant was designed and built for reliably producing a saleable product from the recovered SO2. Criteria are presented to describe some of the features incorporated into the plant design to meet this unique application.
Process simulation of the fluidized‐bed copper oxide process sulfation reaction
Authors: Yeh James T. , Drummond Charles J. , Joubert James I.
Published: February 2007

The Fluidized‐Bed Copper Oxide Process is a regenerative process for the simultaneous removal of both sulfur dioxide (SO2) and nitrogen oxides (NOX) from the flue gas of coal‐fired boilers. An ideal‐flow reactor model for SO2 removal was formulated based on a sulfation reaction kinetics model developed using data from a microbalance reactor. Experimental data obtained from a fluidized‐bed reactor having a cross section measuring 1.02 m by 1.22 m (40 in. by 48 in.) were used to validate the model. The variables in the model were systematically varied to predict reactor performance under different operating conditions. The process variables studies were (1) sorbent copper content, (2) reactor bed depth, and (3) reaction temperature. The reactor performance predictions showed that increasing the copper content of the sorbent from 5 percent to 7 percent would lower the required sorbent recirculation rate by 30 percent. The expanded‐bed depth in the reactor was also an important parameter. Effective performance of the process can be obtained with lower sorbent recirculation rates if the expanded‐bed depth in the reactor is increased.
Stabilization of cadmium and lead in portland cement paste using a synthetic seawater leachant
Authors: Campbell Kristine Melchinger , El‐Korchi Tahar , Gress David , Bishop Paul
Published: February 2007

The seawater leachability of cadmium and lead sludges solidified in portland cement paste was investigated. The leachates of the wastes containing cadmium and lead were analyzed for metal contents using flame atomic absorption spectrophotometry (AAS) as well as pH and alkalinity. A control sample containing only portland cement paste was also leached to serve as a comparison. Results show that the total cadmium leached from the stabilized waste over a 50‐day period was about 1.0% of the total cadmium added to the paste. Lead was not detected in the leachate, however, this could be due to physical and analytical interferences associated with lead. The pH and alkalinity data show that initially, hydroxide is leached from the waste and calcium carbonates are formed on the particle surfaces. After a 50‐day period, the pH and alkalinity of the waste leachates approach that of the seawater leachant.

The microstructure of the waste samples was investigated using scanning electron microscopy (SEM), energy dispersive X‐ray analysis (EDXA) and powder X‐ray diffraction (XRD). The presence of lead did not appear to have an effect on the hydrated structure of the portland cement paste, whereas cadmium seemed to create a more porous microstructure with abundant colloidal ettringite (a calcium sulfoaluminate compound often found in hydrated portland cement paste). Results show that the fixation of cadmium in portland cement paste accelerates sulfate attack on the paste by seawater, which in turn leads to destructive cracking of the paste. It appears that cadmium release is related to the physical destruction of the portland cement paste.
Development of a data base for modelling adsorption of inorganics on iron and aluminum oxides
Authors: Dzombak David A. , Morel François M. M.
Published: February 2007

Although there is an abundance of data for equilibrium adsorption of inorganic ions on hydrous oxides and surface complexation models are capable of fitting the data with only a few adjustable parameters, these models have not been used in practice because of the lack of consensus as to the “best” model and the lack of a coherent compendium of equilibrium adsorption constants. To remedy this situation, a thermodynamic data base for inorganic adsorption is being developed from original data using a simple yet widely applicable model. The resulting data base can be included in general chemical equilibrium computer programs and used to predict adsorption (outside as well as within the range of calibrating data) in aqueous systems containing oxide surfaces. Both the model and the parameter extraction procedure are presented, and results for adsorption of some cations on hydrous ferric oxide are reported and discussed.
Controlling acid deposition by seasonal gas substitution in coal‐ and oil‐fired power plants
Authors: Galeucia Gary , Golomb Dan , Fay James A.
Published: February 2007

Based on evidence that the rate of wet sulfate deposition in eastern North America is higher in the summer half of the year than in the winter half, seasonal control of emissions is proposed as a means of minimizing acid deposition control costs. This paper evaluates the proposal that natural gas be substituted for coal and oil in electric power plants during April through September. A model is presented that simulates the substitution of natural gas for coal and oil in power plants in the eastern 31 state region, so as to minimize total costs with respect to deposition reductions at an Adirondack receptor. The results of the model show: 1) the increased effectiveness of seasonal versus year‐round controls; 2) changes in fuel consumption levels as a result of substitution; and 3) the costs of achieving various levels of deposition reduction at an Adirondack receptor. The costs of seasonal gas substitution are compared to cost estimates for other proposed control methods. The conclusion is that seasonal gas substitution is cost‐competitive with other control methods, at least in some plants and states.
The assessment of risk at superfund sites
Authors: Lincoln David
Published: February 2007

Risk assessments are one component in the evaluation of potential impacts of remedial alternatives at Superfund sites. They inherently involve uncertainty and incomplete scientific understanding. There is general agreement in the risk assessment community on the broad categories of activities to be performed (i.e., exposure, hazard, and risk assessments), but the method of analysis for each element within an activity is presently not uniformly established. The objective of this paper is to describe judgmental decisions that must be made by the risk assessors during the design and execution of a Superfund site assessment, with a focus on the issues of uncertainty and exposure scenarios. The assessment at Western Processing, Washington, is used as an example of the substantial expert judgment required in choosing the analytical methods and appropriate assumptions.
Prediction of organic chemical fates in biological treatment systems
Authors: Blackburn James W.
Published: February 2007

Attention is presently being focused on the fates of organic chemicals in biological treatment systems. Most systems have been designed and operated to remove organic compounds from the aqueous waste stream and performance has been defined in terms of removal of a non‐specific parameter from the wastewater. Parameters like total organic carbon, biochemical oxygen demand, and chemical oxygen demand have historically been used in treatability studies, in system design, and in determining system performance. Performance data using these approaches are inadequate for determination of the removal of specific compounds unless (fortuitously) the specific compound's biological activity is approximated by the generalized activity of the non‐specific parameter.

The resulting assumption that the biokinetics, and therefore the fate of organic compounds, are similar and well‐described by the biokinetics of the non‐specific parameter does not hold for specific chemicals that possess strong stripping/volatilization and/or biomass sorption tendencies or for compounds that have biotransformation kinetics that differ from the idealized “BOD‐like” compound.

Some compounds are likely to preferentially strip/volatilize or sorb onto biomass either if generally recalcitrant to biotransformation, or if the biotransformation process is variable and the rates of the competitive fate mechanisms are large relative to the low transient biotransformation rate. All of the above cases have been experimentally documented and will be discussed. The biotransformation rates have the greatest magnitude of variation of any fate‐related parameter and therefore have a major influence on the compound fate. An equation coupling the competitive fates of organic chemicals in completely‐mixed and steady‐state biological treatment systems has been developed and is presented. This equation can be arranged to allow calculation of the fraction or percentage of an organic compound fed to a system that strips, sorbs onto biomass, biotransforms, or remains in the effluent if the stripping, sorption, and biotransformation rates are known. It can be used to correct experimental data to account for the competitive mechanisms and generate more reliable biotransformation data. Finally, it also serves as a unifying approach against which the specific fate performance of a given system may be compared. Therefore it may be used to estimate potential organic air emissions and the potential of toxic organics in sludge generated from the biological waste treatment process.
Managing hazardous waste risks under the Massachusetts “Superfund” law
Authors: Paulsen Frederick S.
Published: February 2007

Different options and strategies for managing hazardous waste risks are presented. Experience in Massachusetts under a state “Superrfund” law (Chapter 21E) as applied to the selling, buying, and financing of real estate is drawn upon.

The sites in question are not “Superfund” sites. They are those commonly found in a state with a history of many old industries as well as with the expected number of gas stations with underground tanks. The approach discussed is that with a thorough site assessment involving historical research and if required, soil and ground water examination, the parties (sellers, buyers, and lenders) through use of a variety of special devices may successfully consummate real estate transactions. These devices include use of indemnification agreements, escrow funds, title insurance, and in some cases involve accomplishment of tank and contaminated soil removal before closing the real estate transaction.

Not following this course of action exposes some or all of the parties to the risk of liability for cleanup costs as well as for claims by other parties to the transaction.
Intermedia transport of organic compounds in biological wastewater treatment processes
Authors: Barton Douglas A.
Published: February 2007

Organic compounds present in many industrial effluents are transported to varying extents to the gaseous or solid phase, in addition to potential biodegradation, during treatment. Knowledge of the fate of such compounds is critical for making valid policy and engineering decisions regarding issues such as the disposal of sludges, effluent toxicity, and emissions to the ambient air. To quantify the relative distribution of the fate of selected groups of compounds, a mathematical model is presented which describes the intermedia transport mechanisms including volatilization, solids sorption, and biodegradation. The extent of removal via each modeled pathway is a function of the physical properties of the specific compound and the process design and operational parameters of the system.
Prediction of activated carbon adsorption performance under high relative humidity conditions
Authors: Keener Tim C. , Zhou Derong
Published: February 2007

Humidity effects on carbon adsorption were investigated using five volatile organic compounds (VOCs). Relative humidities ranged from 54% to 92%. Under these high relative humidity conditions, the Dubinin–Polanyi equation was used to analyze the results of activated carbon adsorption capacity. Based on the Dubinin–Polanyi equation and the concept of a mass transfer zone, an adsorption kinetic equation was derived to predict the carbon adsorption (MTZ) velocity and the adsorbate concentration profile in the bed.
The impact of internal phosphorus loading on the restoration of Trout lake
Authors: Goetzman Jeffrey S.
Published: February 2007

The accelerated eutrophication of many lakes by society is a problem of increasing concern. The increase in photosynthetic productivity may decrease water clarity, alter dissolved oxygen profiles, and decrease the aesthetic value of a lake. For those lakes which possess high levels of water quality, the need for lake management arises. The first step in developing management techniques for any lake is to collect baseline data—primarily measurements of temperature, dissolved oxygen, transparency, and calculation of a lake's morphometric parameters. Beaulac, Reckhow, and Simpson (1980) [1] indicate that the analysis of lake water nutrient concentration (phosphorus/nitrogen) and calculation of annual nutrient budgets are important additions to baseline data. By studying a lake and its watershed, relationships fundamental to the development of lake prediction models may be determined which operate as a function of nutrient–related parameters such as the areal phosphorus and water loading to a lake.

Quantitative changes in phosphorus loading can be interpreted to provide changes in lake water phosphorus concentration and subsequently trophic status. Predictions made through the use of such models serve as a basis for management decisions.
Separation of hazardous organics by reverse osmosis membranes
Authors: Williams M. , Deshmukh R. , Bhattacharyya D.
Published: February 2007

Extensive experimental studies showed that thin‐film, composite membranes can be used effectively for the separation of selected hazardous organic compounds. This waste treatment technique offers definite advantages in terms of high solute separations at low pressures (<2 MPa) and broad pH operating range, and the use of charged membrane would allow the selective separation of some organics from feeds containing high salt concentrations. In addition, feed pre‐ozonation of selected organics has been shown to provide significant improvement in flux and rejection characteristics for both charged and uncharged membranes due to formation of ionizable organic acid intermediates during the ozonation that do not interact as strongly with the membrane. It has been shown that the overall ozonation–membrane process could be greatly effective in producing permeate water of high quality while minimizing the volume of waste that must be further treated. Batch adsorption studies were also utilized to understand the membrane flux drop phenomena in non‐ozonated solutions.
Supercritical CO2‐cosolvent extraction of contaminated soils and sediments
Authors: Dooley Kerry M. , Ghonasgi D. , Knopf F. Carl , Gambrell Robert P.
Published: February 2007

DDT‐ or PCB‐contaminated topsoils of high organic content were extracted using supercritical CO2 or CO2‐5 wt% cosolvent (toluene, acetone, methanol, acetic acid, diethylamine) mixtures at 313 K and 101 bar. In separate experiments, the pure contaminants were dissolved in supercritical CO2 at the same conditions and the equilibrium solubilities determined. Most of the cosolvents only marginally improve extraction rates over the case of pure CO2. Methanol, however, increases total amounts of DDT removal from 50–80% to > 95%, and increases DDT and PCB extraction rates by as much as an order of magnitude. Methanol is a superior cosolvent probably because its hydrogen‐bonding ability is better suited to interaction with the organic matter in the soil (humic acids, fulvic acids, polysaccharides); the organic matter essentially “dissolves” the contaminants in the soil matrix. Comparing a simple fixed–bed, local equilibrium (based on pure contaminant equilibria) desorption model to the actual desorption data indicates that contaminant solubilities in supercritical fluids are enhanced (over the pure contaminant case) when desorbing from soils. The enhancements may be related to the simultaneous desorption of other low molecular‐weight organics from the soils.
Heterogeneous photocatalysis for water purification: Contaminant mineralization kinetics and elementary reactor analysis
Authors: Ollis David F. , Turchi Craig
Published: February 2007

Heterogeneous photocatalysis is the third and newest of an emerging series of photolytic technologies for water treatment and purification. The earlier examples of ultraviolet ozonation and ultraviolet peroxidation involved direct photoactivation of the contaminant and/or dissolved oxidant and are dominated by solution phase chemistry. Photocatalysis, in contrast, involves photoactivation of the heterogeneous catalyst (an example of indirect photochemical processes) and is dominated by reaction events initiated at the catalyst surface. This paper summarizes (1) current rate equations for photocatalyzed simultaneous destruction of multiple oxidizable organic contaminants and (2) simplified convective transport equations appropriate to photoreactor design under various degrees of fluid mixing and simultaneous reaction contributions by heterogeneous (photocatalyzed) as well as homogeneous reactions.
Feasibility of using alginate to absorb dissolved copper from aqueous media
Authors: Jang L. K. , Brand W. , Resong M. , Mainieri W. , Geesey G. G.
Published: February 2007

Alginate (a biopolymer from kelp and some bacterial strains) is known to absorb copper favorably in the presence of other cations. In this work, the feasibility of using a 2‐liter batch three‐phase (air/liquid/alginate gel) loop fluidized bed reactor to polish water containing 10–150 ppm dissolved copper was investigated. Three methods were tested: (1) Calcium alginate spheres, prepared by dispensing sodium alginate (3.2 wt. % in water) into a 0.05 M calcium nitrate solution, were used as the absorbent, (2) the alginate spheres were formed in situ by dispensing the sodium alginate solution directly into the reactor fluid, and (3) same as (2) except that a trace amount of EDTA was added to the alginate solution. Batch absorption data showed that Method 3 yielded the best result; the concentration of dissolved copper was successfully reduced from 140 ppm to 10 ppm with 3.2 g sodium alginate and 0.2 g EDTA used. However, when the initial concentration was below 40 ppm, both Method 2 and Method 3 are not recommended because the concentration of dissolved copper was too low to allow in situ formation of alginate spheres. Method 1 was found to be useful for treating water containing 10 ppm dissolved copper. But the competition from calcium seriously affected the effective capacity of the alginate for copper. The application of the classical shell progressive model to describe the absorption kinetics was discussed.
Oxygen membrane electrode used as a toxicity biosensor
Authors: Goldblum David K. , Holodnick Steven E. , Mancy Khalil H. , Briggs Dale E.
Published: February 2007

Three biosensor configurations that included a dissolved oxygen electrode and yeast cells (Saccharomyces cerevisiae) were evaluated as a means to assess the environmental effects of toxic chemicals. The configurations were: closed suspension—assay medium closed to air and cells suspended in the medium; open suspension—assay medium open to air and cells suspended in medium; and biofilm electrode (BFE)—assay medium open to air but cells immobilized on the surface of the electrode. The BFE was the most advantageous configuration based on assay times and detection limits.
Development of an immobilized microbe bioreactor for VOC applications
Authors: Friday David D. , Portier Ralph J.
Published: February 2007

In this paper, the technical challenges to building a bioreactor capable of removing significant amounts of chlorinated VOCs (ethylene dichloride specifically) from groundwater or wastewater effluents is discussed. Key considerations include appropriate construction materials, selection of a low cost microbial immobilization support, identification of microorganisms with high VOC metabolic uptake rates, reactor instrumentation and control system, optimum reactor mixing environment, and reactor aeration methods. Operation configuration and techniques to maximize performance in a 75‐liter pilot reactor are presented with field performance data.
New storm water regulations impact industry
Authors: Gemar Claudia
Published: February 2007

In November 1990, new Environmental Protection Agency (EPA) regulations aimed at governing the discharge of storm water from industrial facilities became effective. Because some industrial runoff contains toxics and other pollutants, the EPA considers storm water a major source of water contamination. The new regulations will have a profound impact on the National Pollutant Discharge Elimination System (NPDES) permit requirements for industry. This paper summarizes the new storm water regulations, focusing on the requirements for industrial facilities. It also presents suggestions for compliance.
Development of a transportable thermal separation process
Authors: Ayen Richard J. , Swanstrom Carl
Published: February 2007

A new process for remediation of organics‐contaminated soils and sludges has been developed. The process consists of a soil dryer and a gas separation system. The dryer heats the soil indirectly to 200–450°C in a rotary kiln, volatilizing the water and organic contaminants. No oxygen is present, and no organic destruction or incineration occurs. The dry treated soil discharged from the dryer is used for backfill at the site. The gas separation system condenses and collects the volatilized contaminants. The vapors are first sent to a water spray scrubber to remove the dust, then are cooled with heat exchangers to about 4°C to condense the water and organics. The water is treated and used to wet the cleaned soil or discharged, as appropriate, while the organics are shipped offsite for later treatment. Most of the remaining gas is reheated and recycled to the dryer. The gas not recycled is cleaned and vented. Development has progressed from laboratory and pilot units to a full commercial scale unit capable of processing 115 metric tons per day of soil with 20% moisture. Soil contaminants effectively removed include polychlorinated biphenyls (PCBs), petroleum hydrocarbons and chlorinated hydrocarbons.
Limiting emissions of the greenhouse gas, CO2
Authors: Simpson Theodore B.
Published: February 2007

While considerable global warming uncertainties remain, limiting the emission of the greenhouse gas, CO2 at minimum cost is a growing social concern. An approach suggested is to genearte electricity by processes that facilitate capture of the CO2, and then to compress and inject it into suitable underground formations. By using formations containing uneconomical deposits of energy sources such as oil, gas, Fe+ +, coal, etc., underground bioconversion of the CO2 to recoverable fuel forms may prove possible.
Estimation of VOC emissions using the BASTE model
Authors: Corsi Richard L. , Card Thomas R.
Published: February 2007

Emissions of volatile organic compounds (VOCs) from wastewater raises concerns as many VOCs are photochemically reactive and contribute to the formation of tropospheric ozone, and may be toxic with subsequent adverse affects on human health. Many municipal wastewater treatment facilities (WWTFs) and industries are, or will be, required to complete extensive VOC emissions inventories. Accurate VOC emission models are desirable to facilitate such inventories, and to serve as alternatives to resource‐intensive air sampling at all processes within WWTFs. A flexible VOC fate model (Bay Area Sewage Toxics Emissions: BASTE) has been developed to simulate a wide range of treatment configurations within WWTFs. In addition to its ability to simulate complex treatment trains, BASTE has several features not found in existing VOC fate models. These features include the ability to (1) simulate covered treatment processes, (2) mix mechanistic emissions estimates with emissions measurements and empirical emission factors, and (3) incorporate measured dissolved oxygen concentrations as surrogate measures of VOC emission potential.
NOx reduction by the Econ‐Nox™ SCR process
Authors: Hardison L. C. , Nagl G. J. , Addison G. E.
Published: February 2007

SCR systems are used extensively in Japan and West Germany to eliminate 80–90% NOx emissions from utility boilers and industrial furnance stacks. Costs have been lowered considerably over the past ten years. Further reduced costs and stringent regulations on NOx emission make this simple system attractive for refinery and industrial process heaters, boilers, and gas turbines.

The Econ‐NoxTM process uses a fluidized catalyst bed to accomplish selective total reduction of oxides of nitrogen to elemental nitrogen using ammonia as a reactant. The process can be designed for operating temperatures between 550°F and 750°F and for a wide range of operating variables.

The process brings together some old technology on selective reduction chemistry, relatively new fluidized bed oxidation techniques and a non‐precious metal Econ‐AcatTM catalyst which permits operation over a broader temperature range than has been practical in the past.

This paper reports some of the distinctions made between this reactor configuration and the historical thermal and catalytic systems used for this type of process.
A Confined Vortex Scrubber for fine particulate removal from flue gases
Authors: Loftus Peter J. , Stickler David B. , Diehl Richard C.
Published: February 2007

An innovative cleanup concept, based on a Confined Vortex Scrubber (CVS), for fine particulate removal from combustion flue gases has been developed, tested and verified. The CVS consists of a cylindrical vortex chamber with multiple tangential flue gas inlets. The clean gas exit is via two central tubes. Water is introduced into the chamber and is confined within the vortex chamber by the extremely high centrifugal forces generated by the gas flow. The confined water forms a layer through which the flue gas is forced to bubble. Due to the high radial acceleration, the bubbles generated are very small, leading to a strong gas/liquid interaction, high inertial separation forces and extremely efficient fine particle cleanup. Collection efficiencies in excess of 99.5 percent have been measured for extremely fine fly ash (mean particle size 3 microns). A collection efficiency of 98 percent has been measured for 0.3 micron diameter particles.
SNRB catalytic baghouse laboratory pilot testing
Authors: Kudlac G. A. , Farthing G. A. , Szymanski T. , Corbett R.
Published: February 2007

The SOx‐NOx‐Rox BoxTM (SNRB) is an advanced air pollution process patented by Babcock & Wilcox (B&W) that provides for significantly reduced sulfur oxides (SOx), nitrogen oxides (NOx), and particulate emissions from coal‐fired boilers. The process uses a high‐temperature catalytic baghouse for integrating SOx reduction through injecting an alkali sorbent (such as hydrated lime or sodium bicarbonate), NOx removal through ammonia injection and selective catalytic reduction (SCR), and particulate collection. The advantages of the process include: compact integration of the emission control technologies into a single component; dry sorbent and by‐product handling; and improved SCR catalyst life due to lowered SOx and particulate levels.

The SNRB concept has been successfully demonstrated in a 1500‐ACFM pilot baghouse at B&W's Alliance (Ohio) Research Center. This paper describes the SNRB technology and presents the SOx, NOx, and particulate removal performance results over a range of operating conditions for the laboratory pilot test program.
Evaluation of the TCE catalytic oxidation unit at Wurtsmith Air Force Base
Authors: Hylton T. D.
Published: February 2007

Wurtsmith Air Force Base is the site of an air‐stripping‐with‐emissions‐control system to remove volatile organic compounds (VOCs), chiefly trichloroethylene (TCE), from groundwater. The purpose of this study was to evaluate the performance of a fluidized‐bed catalytic oxidation unit for destroying halogenated organics with respect to catalyst bed temperature and operating time. The objectives included identification of any products of incomplete combustion formed and determination of the utility costs for the unit. Samples were collected over a period of ∼ 19 months with volatile organic sampling trains according to the Environmental Protection Agency (EPA) Method 30. Samples were taken at catalyst bed temperatures of 315, 370, 425, and 480°C. The results indicate that the incinerator was destroying the TCE with <97% efficiency when operated at ≥370°C. A conservative cost estimate for utilities was determined to be $0.36/1000 gal of water treated.
Pharmaceutical wastewater treatment comparison of process scale‐up from bench to full‐scale: A case study
Authors: Torrens Kevin D. , Musterman Jack L. , Drohobyczer Alexander
Published: February 2007

Wastewater treatability investigations were conduction for a specialty batch pharmaceuticals production facility which typically produces small quantities of numerous chemicals and pharamaceuticals. Production campaigns typically range from two days to four weeks in duration. Due to these production changes, the organic loading and chemical makeup of the wastewater constantly varies, resulting in less than optimum treatment plant performance. In addition, the facility planned to increase production in the future, thereby increasing wastewater flow and organic load.
A review of trace element emissions from the combustion of refuse‐derived fuel with coal
Authors: Norton Glenn A.
Published: February 2007

The effects of cocombusting refuse‐derived fuel (RDF) with coal on stack emissions of trace elements in the ash stream were reviewed. The large number of variables and uncertainties involved precluded drawing definitive conclusions regarding many of the trace elements. However, it is evident that cocombustion resulted in increased emissions of Cd, Cu, Hg, Pb, and Zn. Emissions of As and Ni tended to decrease when RDF was fired with coal. Modeling studies indicated that ambient levels of trace elements during cocombustion should be within acceptable limits. However, periodic monitoring of Cd, Hg, and Pb may be warranted in some instances.
Granular activated carbon pilot treatment studies for explosives removal from contaminated groundwater
Authors: Wujcik W. J. , Lowe W. L. , Marks P. J. , Sisk W. E.
Published: February 2007

Manufacturing activities at Army Ammunition Plants (AAPs) result in the production of organic wastewaters that contain both explosive residues and other organic chemicals. As a result of past waste practices at such plants, explosive residues may leach through the soil and contaminate groundwater. Two pilot studies were performed to evaluate the use of granular activated carbon (GAC) to treat groundwater contaminated with explosives at Badger AAP and Milan AAP. An additional goal of the Badger AAP study was to examine the potential discharge of explosives 2,4‐DNT and 2,6‐DNT from a packed column air stripper used to remove volatile organic compounds from groundwater. A laboratory method was developed for the BAAP study to permit lower detection levels for 2,4‐DNT and 2,6‐DNT (0.46μg/L and 0.017μg/L, respectively). The studies concluded that removal of explosives from groundwater using continuous flow GAC is feasible.
The B.E.S.T.® solvent extraction process treatment of soil, sediment, and sludges
Authors: Jones George R.
Published: February 2007

Many treatment technologies are being used or proposed to remediate hazardous wastes in sites throughout the U.S. These technologies can be broken down into four general treatment categories: destructive, fixation, biological, and separation. This paper will discuss a separation technology: the B.E.S.T. (Basic Extractive Sludge Treatment) process.
Results of field demonstrations of a newly developed pilot‐scale debris washing system
Authors: Dosani M. A. , Taylor M. L. , Wentz J. A. , Patkar A. N. , Barkley N. P.
Published: February 2007

Numerous hazardous waste sites in the United States are littered with metallic, masonry, and other solid debris that may be contaminated with hazardous chemicals [for example, polychlorinated biphenyles (PCBs), pesticides, lead, or other metals]. Although the majority of the debris at Superfund Sites has no potential for reuse, decontaminated debris could either be returned to the site as “clean fill” (rather than being transported offsite to a hazardous waste landfill) or, in the case of metallic debris, it could be sold to a metal smelter.

Previous phases of this project have involved the development of a technology specifically for performing on‐site decontamination of debris. Both bench‐scale and pilot‐scale versions of a debris washing system (DWS) have been designed and constructed. The DWS entails the application of an aqueous solution during a high‐pressure spray cycle, followed by a turbulent wash cycle. The aqueous cleaning solution is recovered and reconditioned for reuse concurrently with the actual debris‐cleaning process, which minimizes the quality of process water required to clean the debris.

This paper presents the results of bench‐scale studies and the results obtained during two field demonstrations of the DWS.
An overview of the pooled emission estimation program (peep) for potws
Authors: Leong Lawrence Y. C. , Regan Margaret M. , Kuo Jih‐Fen , Wong Elizabeth
Published: February 2007

California Air Toxics “Hot Spots” Information and Assessment Act of 1987 (AB 2588) establishes a program to develop statewide inventory of site‐specific air toxic emissions of over 500 compounds. The goals of AB 2588 are to collect emissions data, to identify facilities having localized impact, to ascertain health risks, and to notify nearby residents. Twenty‐four agencies with Publicily Owned Treatment Works (POTWs) initiated a voluntary Pooled Emission Estimation Program (PEEP) at 21 facilities for 18 unit processes. For majority of the unit processes, tests were conducted at three different facilities during each round. The target compounds were selected 21 volatile organic compounds (VOCs), formaldehyde and 2, 4, 6 trichlorophenol. The program collected and analyzed approximately 2060 air samples and 1220 liquid samples to develop emission factors. A QA/QC project plan which included field and laboratory elements were developed and implemented to ensure high quality data. Discussions on the data evaluation procedures, development of emission factors (the ration of the compound released to the air per total quantity of the compound entering a unit process), estimating VOC emissions from a weir using DO measurements, and an emission factor model for estimating air emissions using liquid/sludge VOC concentrations for liquid, sludge and digester gas handling treatment facilities as listed above are provided.
The quality improvement program (QIP): A new regulatory strategy for sustaining long term reductions in emissions from equipment leaks
Authors: Berglund Ronald L.
Published: February 2007

During the remainder of this decade and into the next century, chemical and refining industries will have an unprecedented opportunity to work closely with equipment suppliers, process engineering and construction firms, maintenance personnel, regulators, and the community to improve their environmental performance while enhancing the operation of their facilities. The basis of the strategy for this change will be the new Clean Air Act, which was passed into law in November 1990. The impetus for improvement will be the Quality Improvement Program (QIP) for controlling fugitive emissions from equipment leaks. Although results from the QIP need not be incorporated into the technology of an operating chemical plant or refinery until 1999, best results can be achieved by analyzing monitoring and maintenance information obtained in the early phases of fugitive emissions activity as soon as possible, and utilizing this analysis in evaluating technology and selecting new process design configurations.
Bioremediation of petroleum wastes from the refining of lubricant oils
Authors: Prince Michael , Sambasivam Yasodha
Published: February 2007

The results of an initial feasibility study on the bioremediation of sludge are presented. The sludge used in the study was taken from a site containing waste produced during the refining of lubricant oils to which sulfuric acid had been added. The effectiveness of bioremediation was examined using shake flask experiments with indigenous and other bacteria sources and nutrient supplementation. The initial results show limited effectiveness of biological treatment at conditions employing indigenous bacteria and low (2%) sludge concentraticws in Bushnell‐Haas media. In addition, the indigenous bacteria were seen to degrade the polycyclic aromatic hydrocarbons naphthalene, penanthrene and pyrene which are present at some locations at the site. No apparent degradution of material was seen using conditions of high (30%) sludge concentrations in Bushnell‐Haas medium under a variety of conditions. In addition, nutrients were rapidly depleted at these sludge concentrations, with the exception of sulfates which were produced when high sludge concentrations were used.
Recycling of spent hydroprocessing catalysts: EURECAT technology
Authors: Berrebi G. , Dufresne P. , Jacquier Y.
Published: February 2007

Disposal of spent catalysts is a growing concern for all refiners. Environmental regulations are becoming stricter and State recommendations are to develop disposal routes which would emphasize recycling as much as possible, and processing the wastes as near as possible to the production center. In this context, EURECAT has developed a recycling process for the hydroprocessing catalysts used in the oil refineries (NiMo, CoMo, NiW on alumina or mixed alumina silica). The process starts with a regeneration of the catalyst to eliminate hydrocarbons, carbon and sulfur. After a caustic roasting, the material is leached to obtain a solution containing mainly molydenum (or tungsten) and vanadium and a solid containing essentially alumina, cobalt and/or nickel. Molydenum and vanadium are separated by an ion exchange resin technique. The solid is processed in an arc furnace to separate the alumina. Nickel and cobalt are separated by conventional solvent extraction to obtain pure metal. Alumina is disposed of as an inert slag. The strength of the process lies in the combination of proven technologies applied by companies whose reliability in their respective field is well known. The aspects concerning spent catalyst handling, packaging and transport are also discussed.
Low‐temperature carbon‐based process for flue‐gas cleanup
Authors: Gangwal S. K. , Howe G. B. , Spivey J. J. , Silveston P. L. , Hudgins R. R. , Metzinger J. G.
Published: February 2007

A low‐temperature process employing activated carbon‐based catalysts and operating downstream of the electrostatic precipitator (ESP) is being developed jointly by Research Triangle Institute (RTI) and the University of Waterloo (Waterloo). The RTI‐Waterloo process is capable of removing more than 95% SO2 and 75% NOx from coal combustion flue gas. The flue gas leaving the ESP is first cooled to approximately 100°C. The SO2 is then catalytically oxidized to SO3 which is removed as medium‐strength sulfuric acid in a series of periodically flushed trickle‐bed reactors containing an activated carbon‐based catalyst. The SO2‐free gas is then reheated to approximately 150°C and NH3 is injected into the gas stream. It is then passed over a fixed bed of a different promoted activated carbon‐based catalyst to reduce the NOx to N2 and H2O. The clean flue gas is then vented to the stack. The feasibility of the process has been demonstrated in laboratory‐scale experiments using simulated flue gas. Catalysts have been identified which gave the required performance for SO2 and NOx removal with less than 25 ppm NH3 slip. Potential for producing greater than 10N H2SO4 by periodically flushing the SO2 removal reactor was also demonstrated. Cost for the RTI‐Waterloo process was competitive with conventional selective catalytic reduction (SCR)‐flue gas desulfurization (FGD) process and other emerging combined SO2/NOx removal processes.
Remediation of metal contaminated soil by EDTA incorporating electrochemical recovery of metal and EDTA
Authors: Allen Herbert E. , Chen Ping‐Hsien
Published: February 2007

Removal of toxic heavy metals from a soil matrix by the addition of ethylenediamine tetraacetic acid (EDTA) is an effective means of remediation. The liquid stream containing the metal and chelating agent is amenable to further treatment by electrolysis in which the metal can be separated from the chelating agent. This provides a separated metal that can be removed for reuse or treated for final disposal by conventional technologies and a reclaimed EDTA stream that can be used again for treatment of contaminated soil.

Under the diffusion controlled conditions of polarography or voltammetry, we observed reduction of cadmium, copper and lead ions and their protonated EDTA complexes (MHY−), but not of the non‐protonated EDTA complexes (MY2−). Potentials applicable for metal deposition and, consequently, regeneration of the EDTA were established. To prevent electrochemical oxidation of EDTA during electrolysis we used a cell in which the anode and cathode compartments were separated by a cation exchange membrane. Tests with Pb‐EDTA demonstrated that over 95 percent recovery of both EDTA and lead could be achieved by electrolysis. The lead that was deposited onto a copper electrode was a mixture of hydrolysis products and salts and the lead could be recovered by dissolution in acid. EDTA was equilibrated with soil before addition of lead. When electrolyzed, this sample released EDTA and deposited Pb to approximately the same extent as did the samples that had not been equilibrated with soil.
Biodegradation of Xenobiotics in a fixed bed reactor
Authors: Seignez Chantal , Mottier Vincent , Pulgarin Cesar , Adler Nevenka , Péringer Paul
Published: February 2007

The specific example of an at‐source biological wastewater treatment has been elaborated and developed. A two‐phase fixed‐bed bioreactor system was tested for its efficiency using phenol as a test substance and then, the degradation of sodium anthraquinone‐2‐sulfonate (SAS) was studied and performed.

The continuous aerobic degradation of phenol or SAS as the sole source of carbon was investigated. For SAS degradation with an immobilized mixed bacterial culture, industrial activated sludge was used as inoculum, while for phenol a domestic activated sludge from a municipal wastewater treatment plant and activated Actizym‐sludge prepared with Actizym® powder were applied. In our laboratory fixed bed reactor system the adapted mixed culture was able to degrade up to 0.17 g L−1 h−1 of SAS and 0.28 g L−1 h−1 of phenol at dilution rates of 0.149 h−1 and 0.059 h−1, respectively. The removal efficiency of our two‐phase continuous bioreactor system was about 99% of primary and 90% of ultimate SAS degradation.

In the adapted bacterial culture degrading SAS, pure bacterial strains were isolated and identified; three were gram negative and six were gram positive.
Parameter estimation for trace element sorption on a new granular iron oxide
Authors: Theis Thomas L. , Iyer Ramesh , Ellis Sonia K.
Published: February 2007

In order to acquire information on sorptive systems suitable for predictive and design applications, it is necessary to gather and analyze data in bench or prototype reactors, the most common types being batch and packed column. In this paper, data from both types of reactor are presented and contrasted for the case of two trace elements, cadmium and chromate, sorbing to a granular form of iron oxide. The granular oxide was developed in conjunction with the ALCOA Laboratories specifically for use in column reactors.

Data are analyzed using a surface coordination chemical approach and film transfer, surface and pore diffusion transport models. Governing coefficients are extracted using nonlinear optimization techniques which provide an objective interpretation of the data without the errors introduced by various linear transformations or analysis bias.

Results indicate that both experimental techniques are capable of accurately measuring the equilibrium coordination constant for sorption reactions, however batch estimates for the total sorptive capacities are consistently lower than column estimates, which range from 1.1 mg/g for Cd to 3.3 mg/g for CrO4. In addition, when column adsorption and desorption data are taken together, it is possible to obtain reliable estimates of rate‐controlling parameters. This is not generally possible for batch systems under conditions representative of those encountered during environmental control.
Adsorption of selenium on hydrous alumina
Authors: Ghosh Mriganka M. , Cox Chris D. , Yuan‐Pan Jill R.
Published: February 2007

Adsorption of selenite (SeO) and selenate (SeO) on hydrous alumina (γ‐Al2O3) was studied using batch equilibrium experiments. pH, the single most significant parameter, affected both speciations of selenium (Se) and of surface hydroxo groups on alumina that, in turn, determined the extent of adsorption of the oxyanions. Adsorption of both anions could be described satisfactorily by the Triple Layer Model (TLM). In the presence of SO, Se (VI) adsorption decreased significantly. Fixed bed adsorbers of alumina with an empty bed contact time (EBCT) of 2 minutes or longer provided excellent removal of Se(IV) from dilute aqueous solutions in the pH range of 5 to 8 for a long period. Spent alumina beds were successfully regenerated with 0.25 percent NaOH solution followed by rinsing with deionized water and 0.05 M HCl. While two percent of alumina was lost per cycle on an average, the loss in adsorption capacity of regenerated alumina was insignificant.
A batch reactor for monitoring process dynamics during biodegradation of volatile organics
Authors: Skeen Rodney S. , Truex M. J. , Petersen J. N. , Hill J. S.
Published: February 2007

Data are presented that demonstrate a batch reactor that allows accurate monitoring of process dynamics during biodegradation of volatile organics. Using this system, many samples can be removed in a aseptic fashion, allowing frequent measurements of the concentrations of biomass, electron donors, electron acceptors, and volatile compounds. Additionally, the reactor is well instrumented, allowing the continuous monitoring of pH, oxidation/reduction potential, pressure, and temperature. The reactor is constructed entirely of materials which have minimal interaction with volatile organic compounds. It is also demonstrated that sample removal does not cause losses of volatile compounds since the sampling ports are double sealed, making use of both gastight stainless steel ball valves and Teflon‐lined septa.