Improving Clearwell Design for CT Compliance
M. M. Clark,* J. J. Ducoste, C. Burns
John Carollo Engineers/American Water Works Association Research Foundation

Computational fluid mechanics will be used to characterize circulation in large municipal drinking water storage systems. With these simulations, residence time density functions for the continuous process will be developed, and existing designs will be modified in order to increase the plug flow nature of the systems. This is important to increase the disinfecting capabilities of the systems and insure safer water supplies. The simulations will be compared with measured residence time distributions from pilot and full-scale systems. If this approach is successful, it will be possible to replace costly and time-consuming pilot testing and trial-and-error full-scale design with numerical simulation techniques.

Development and Characterization of UF Membranes and Relation of Membrane Properties to Adsorptive Fouling
M. M. Clark,* P. Lucas, Y. Lee, G. Koch, Y. Wang, C. Combe, M. Kumar
National Water Research Institute; University of Illinois; Lyonnaise des Euax in collaboration with Separation Systems Technology

The objectives of this project are to: cast UF membranes from various polymer formulations, modify membrane surfaces to create different charge, roughness, porosity, and hydrophobicity, examine membrane surfaces with classic and emerging tools from materials and surface chemistry (AFM, ATR-FTIR, XPS, streaming potential, contact angle), study the adsorption of natural organic materials on the membranes, model adsorption and membrane fouling, and understand what physical-chemical characteristics of membranes and solutions are most important in membrane fouling. Significant development of surface analysis methods is also envisaged.

Natural Organic Matter (NOM) Rejection by, and Fouling of, Nanofiltration and Ultrafiltration Membranes-Bench-Scale and Pilot-Scale
M. M. Clark,* P. Lucas, Y. Lee, G. Koch, Y. Wang, C. Combe, M. Kumar in collaboration with the University of Colorado
American Water Works Research Foundation

Experimentation and modeling are used to provide a comprehensive assessment of NOM and membrane interactions in water treatment. This will provide a basis for membrane selection to achieve maximum NOM rejection with minimal fouling. Our work will evaluate well-characterized nanofiltration and ultrafiltration membranes using well-characterized NOM under various water quality conditions. A bench-scale testing program will be performed to assess spiral wound membranes and hollow fiber membranes. A parallel pilot testing program will be undertaken to provide a comparison of bench-scale versus pilot-scale trends in NOM rejection and fouling. The data will be mathematically modeled to provide insights into mechanisms of NOM rejection and fouling.

Decatur/Danville, Ill., Nitrate/Pesticide Removal Project
M. M. Clark,* B. Hackman
Electric Power Research Institute, Community Environmental Center; Illinois Power Co.; Illinois Waste Management and Research Center

The objective of this project is to determine how best to apply membrane filtration processes to simultaneously remove turbidity, pathogenic organisms, nitrate, and pesticides. The pilot facility consists of pretreatment using ultrafiltration to which powdered activated carbon is added for enhanced organics removal and fouling control. The permeate from the ultrafiltration stage then passes to an RO unit for nitrate and pesticide removal. The pilot systems will be set up at the South Water Treatment Plant in Decatur, Illinois. The pilots will be fully automated, and communication software will allow remote control and data logging from the University of Illinois, about 45 miles from Decatur. Membranes have been donated to the project from five different companies.

Vulnerability of Water Resources to Global Climate Change in the Agricultural Midwest-Ecological, Economic, and Regulatory Aspects
J. W. Eheart,* E. E. Herricks*
U.S. Environmental Protection Agency, R824-785

This research assesses vulnerability of linked ecological, economic, and regulatory systems to climate change in the central North American agricultural areas, using Illinois as an example. The ecological analysis focuses on streamflow, using habitat frequency analysis for fish and invertebrates. The economic analysis focuses on the effect of perceived future rainfall on streamflow through the acquisition and use of irrigation systems. The focus of the regulatory analysis is the responsiveness of water quality regulation to changing streamflow/dilution calculations that establish the base for permitting and ambient water quality maintenance. Linking these issues at the watershed level provides the foundation for the examination of policy to address vulnerability to competing demands on limited water resources.

Colloidal and Macromolecular Transport in Thin Layers Near Microporous Membrane Surfaces
M. M. Clark,* K. Howe; P. Aimar, P. Bacchin, and C. Guigui (CNRS)
University of Illinois; Centre National de la Recherche Scientifique, France

The objective of this U of I-CNRS collaboration is to better understand the dynamics of thin, concentrated, particulate, and macromolecular boundary layers near membrane surfaces and the interaction of colloidal particles and organic molecules with synthetic membranes. This work includes modeling of mechanics of concentrated particle or colloidal suspensions near porous membrane surfaces and incorporation of these models in an overall model of mass transport in membrane separation processes.

Real-Time Effect Monitoring for Episodic Event Toxicity
E. E. Herricks,* T. Looby
University of Illinois

The objective of this research is the development of methods to perform in situ measurement and analysis of episodic event toxicity associated with stormwater flows. Specific objectives include: (1) the evaluation of the asiatic clam Corbicula sp., and other mussels and aquatic invertebrates common in Illinois, as test organisms in a commercially available monitoring system (MosselMonitor manufactured by Delta Consult, The Netherlands), (2) laboratory and field evaluations of response spectra of Corbicula and other organisms to changing environmental conditions and episodic exposure to contaminants, and (3) development of advanced methods of data analysis from continuous monitoring systems.

Toxicological Analysis of Exposure Regime and Significance for Environmental Management
R. Brent,* E. E. Herricks
U.S. Enviromental Protection Agency STAR Fellowship Program

The goal of this research is to investigate the effects of discontinuous, or intermittent, pollutant exposures on organisms, populations, and biological communities. The testing includes the refinement of test procedures with species commonly used in toxictiy testing. Although frequency is defined as the number of repetitions of an event within a given time period, issues of frequency in toxicity also include the interval between exposure events, which may be fixed or variable. Species- and contaminant-specific recovery times estimated from brief exposure testing will be the basis for investigating the effects of intermittent exposures in this research.

Evaluation of Hormesis in the Microtox Assay Using Binary Mixtures
E. E. Herricks,* C. Youngblood
Azure Corp.; U.S. Environmental Protection Agency STAR Fellowship Program

The Microtox assay has been used to evaluate stormwater samples from over 50 storms. A common occurrence was the evidence of stimulation in the assay, an indication of sensitivity to low concentrations of contaminants. Initial experimentation with single chemicals, both metals and organic compounds, indicated stimulation at low concentrations. This research has confirmed the increased stimulation produced by binary mixtures. In binary mixtures, stimulation levels comparable to stormwater samples have been produced in binary mixture experiments. This research is demonstrating the high sensitivity of the Microtox to common pollutants and demonstrated additional applications of the assay in environmental monitoring.

Constructed Wetland Response to Dynamic Loading of Pollutants
E. E. Herricks,* J. D. Eppich
University of Illinois; Village of Homewood, Ill.

Constructed wetlands are used as a best management practice for stormwater quality control. These stormwater wetlands present new design challenges to both engineers and ecologists. For engineers, stormwater wetlands are open systems with indeterminant design elements. To ecologists, they are artificial systems that may or may not respond as natural wetlands to pollutant loading. This research explores the response of constructed stormwater wetlands to dynamic loading typically associated with urban stormwater runoff. The objective is the use of experimental wetlands to identify fundamental processes associated with water quality control in these modified ecosystems. The effects of a heavy metal (Zn) has been evaluated, and studies continue of a biofiltration wetland system.

Remediation and Ecological Restoration of Polluted Wetlands
E. E. Herricks,* G. Roadcap,* R. Raman, M. B. Wentzel
U.S. Enviromental Protection Agency, Great Lakes National Program Office

The goal of this research is to develop and test methods of restoring wetland habitats using physical/chemical remediation processes and hydroperiod management to improve water quality and restore wetland plant communities. The physical/chemical remediation will focus on controlling the deposition of contaminated sediments, and hydroperiod management will be developed to improve water quality and sustain a healthy wetland ecosystem through vegetation management. As an element of the restoration activity, methods will be developed to assess restoration success based on both direct toxicity and ecosystem measures.

Getting Public Guidance on Environmental Aspects of Stormwater Control
E. E. Herricks,* R. Liebert,* P. Cabot
Partnership Illinois Seed Grant Program

Stormwater ordinances now require local control of stormwater, typically in small detention ponds. The design of these ponds follows common engineering practice, but the proliferation of ponds, and an increase in residential applications, suggests that engineering designs should also consider a community context and aesthetics. This research will develop a protocol for the improved design of stormwater detention facilites. A major focus of this protocol will be the inclusion of a community context in initial design considerations and guidance for the appropriate selection of aesthetic elements for a community context.

Watershed Protection in Agricultural Environments-Integrated Social, Geomorphological, and Ecological Research to Support Ecosystem-based Stream Management
E. E. Herricks,* B. L. Rhoads,* D. L. Wilson, M. Tompkins, T. Hauser
U.S. Environmental Protection Agency

This research advances the proposition that watershed protection, although dependent on science and engineering, is a process that is fundamentally social in nature. The research will focus on how new scientific and engineering knowledge affects how stakeholders value natural resources, specifically habitat and fisheries, and, in turn, how they approach stream management. The research is based on an interdisciplinary approach that combines theoretical perspectives in social theory with a scientific perspective based on geomorphology and ecology. Community-based watershed projects in the Embarras, Salt Fork, and Sangamon river basins will serve as case studies.

Vulnerability of Water Resources to Global Climate Change in the Agricultural Midwest
J. W. Eheart,* E. E. Herricks*
U.S. Environmental Protection Agency

This project has determined the sensitivity and vulnerability of water resources to climate change using links among natural resources, economic, and regulatory indicators. The project uses changes in stream flow caused by climate change and the potential for increased off-stream use from irrigation and domestic water supply needs. An analysis shows that irrigation use affects stream flow when the mean precipitation drops to around 25% below the historical average potential. The impact of climate change on natural resources is being assessed using the analysis of fisheries community response to changing stream flows using both habitat modeling procedures and community vulnerability analysis.

Development of an Integrated Scientific and Technological Framework for Stream Naturalization
B. L. Rhoads,* M. García, E. E. Herricks, D. Wilson
U.S. Environmental Protection Agency

The watershed approach to environmental management emphasizes that decision making should occur at the level of local communities. This requires an integrated scientific and community-based framework for decision making-a social and scientific enterprise referred to as naturalization. Naturalization involves a recursive interplay between a community's vision of the stream and the scientific/technical perspective on what the streams can realistically become to achieve the community's vision. This research will explore naturalization programs, integrating both the technical/scientific and social aspects of community-based watershed management. Three watersheds in Illinois are the focus of a three-year research effort initiated in 1998.

The Role of Carbonaceous Aerosols in Climate Forcing
A. Dillner,* S. M. Larson
U.S. Environmental Protection Agency STAR Fellowship; University of Illinois

Carbonaceous aerosols (elemental and organic carbon) can act to either cool or warm the climate. This project addresses this issue by providing size segregated measurements of the absorption efficiency for laboratory generated and midwest ambient EC useful for regional positive forcing determinations. Organic carbon may be a large part of negative forcing. However, accurate determination of the forcing role of organics is limited because of uncertainties of identification, size distribution, refractive indices, and humidity growth. In this project, we will investigate these and provide an approach to estimating organic forcing.

Analysis of a Preliminary Data Set Describing Size-segregated Concentrations of Carbonaceous and Sulfate Aerosols
S. M. Larson,* A. Dillner
University of Illinois

Size-segregated samples of ambient aerosols will be analyzed for concentrations of elemental and organic carbon and sulfates, providing new insights on climatic effects of aerosol paticles and on measurement of carbonaceous aerosols. Over 700 filter and impactor samples will be collected in the study, characterizing the ambient aerosol in 8 size ranges below 10 mm over a summer period. We will compare methods of measuring elemental carbon, including one developed in this project and investigate the physical, optical, and forcing properties of carbonaceous and sulfate aerosols.

Carbon Monoxide Analysis for Highway Projects
S. M. Larson,* F. Coleman, S. Peters, P. Gollapalli
Illinois Transportation Research Center

A screening model is often a first step in analyzing potential air pollution problems, utilizing readily available data to make a conservative estimate of a source contribution to ambient pollutant concentrations. A more sophisticated model can be subsequently applied, if the screening model indicates its necessity. The screening model approach is not currently used for highway projects in Illinois but could make the procedure for CO analysis for highways more efficient. In this project, screening and refined CO models for highway projects will be studied and validated. An acceptable CO screening model for Illinois highway projects will then be developed.

Controlling Cryptosporidium in Drinking Water Supply for Small Communities
B. J. Mariñas,* J. L. Rennecker, S. A. Rubin, K. M. Ruffell
Illinois Water Resources Center

Cryptosporidium parvum oocysts are highly resistant to inactivation by disinfectants primarily because the mass transfer of these reactive molecules suffers retardation due to a combiation of low diffusivity and high reactivity within the oocyst wall prior to reaching the sporozoites. However, oocysts have a tendency to excyst, fully or partially, in water samples because of certain changes in environmental conditions, thus exposing the more vulnerable sporozoites to disinfectants. The objective of this project is to investigate oocyst excystation trigger processes, with the ultimate goal of developing a cost-effective treatment strategy for providing safe drinking water to small communities using surface water. The strategy under consideration includes three steps: excystation trigger, holding pond retention, and disinfection.

Microbial Removal and Integrity Monitoring of High-Pressure Membranes Used for Water Treatment
B. J. Mariñas,* C. L. Acker, C. K. Colvin, J. R. Elarde
CH2M Hill; American Water Works Association Research Foundation; U.S. Bureau of Reclamation

The main objective of this project is the bench-scale development of a method for assessing the presence and size distribution of membrane pinholes and other imperfections in reverse osmosis and nanofiltration membrane systems. Membrane imperfections of interest are those that permit the passage of a small fraction of viral, bacterial, and protozoal pathogens without resulting in measureable changes in product water conductivity or total dissolved solids concentration. It is anticipated that the final method for characterizing membrane imperfection size distribution will include the use of fluorescent-dyed polystyrene microspheres of various sizes as nonbiological surrogate indicators of viruses, bacteria, and protozoa cysts/oocysts.

Titanium Dioxide Photocatalytic Treatment of Organic Vapor Emissions
B. J. Mariñas,* K. K. Lew, M. Herrera
U.S. Army Construction Engineering Research Laboratories, DACA88-97-Q-0124

The objective of this project is the assessment of the titanium dioxide (TiO2) photocatalytic destruction efficiency of methyl ethyl ketone (MEK) and toluene in simulated air emissions. Experiments are being performed with an annular photocatalytic reactor including turbulence promoters and a thin film of TiO2 immobilized by a chemical vapor deposition method. MEK has been found to form a reactive intermediate under dark conditions. The MEK conversion efficiency in the presence of photons was found to correlate well with the formation of the intermediate. The destruction efficiency of toluene was observed to increase drastically in the presence of water vapor.

Remote Control/Sensing for Small Drinking Water Systems
B. J. Mariñas,* V. L. Snoeyink,* K. M. Ruffell
Battelle; U.S. Environmental Protection Agency

The overall objective of this project is the development of water treatment strategies based on the use of processes amenable to remote control/sensing. Initial research efforts include the development of recommendations for remote monitoring of various water quality and processes operating parameters and the potential for remote control and operation of treatment processes within the frame of small systems. Recommendations are also being developed for the final design and demonstration of a prototype remote-control/sensing system, as well as the selection of the optimum types of processes/treatment plants to be used for the demonstration. Subsequent phases of this study will focus on the development and testing of new sensors.

Inactivation of Cryptosporidium parvum Oocysts with Potassium Permanganate
B. J. Mariñas,* K. M. Ruffell
Carus Chemical Co.

The primary objective of this study was to assess the inactivation of Cryptosporidium parvum oocysts with potassium permanganate. Experiments were also performed with ozone and monochloramine for the purpose of serving as common disinfectant references with relatively fast and slow C. parvum inactivation. Data on the inactivation of Giardia muris cysts with potassium permanganate were also investigated. Synergistic effects were observed for the sequential disinfection of ozone followed by potassium permanganate as a secondary disinfectant.

Titanium Dioxide Photocatalytic Treatment of Xylene Vapor Emissions from Surface-coating Operations
B. J. Mariñas,* K. K. Lew
U.S. Army Construction Engineering Research Laboratories, DACA88-98-Q-0188

The objective of this study is the development of a heterogeneous titanium dioxide (TiO2) photocatalytic process for the treatment of xylene vapor emissions from U.S. Army surface-coating operations. The scope of work is designed to assess the potential of the photocatalytic process for achieving xylene degradation efficiencies greater than 90% and completing the oxidation of the converted fraction of xylene vapor into carbon dioxide and water. More specific tasks include: (1) assessment and optimization of xylene degradation efficiency, (2) assessment and optimization of xylene mineralization, and (3) development of technology transfer recommendations.

Integrated Approach for the Control of Cryptosporidium parvum Oocysts and Disinfection By-Products in Drinking Water Treated with Ozone and Chloramines
B. J. Mariñas,* R. A. Minear,* K. M. Ruffell, H. Lei
U.S. Environmental Protection Agency, STAR Grant Program, EPA R826830-01-0

The overall goal of this project is to develop process design recommendations for the simultaneous control of Cryptosporidium parvum oocysts and disinfection by-products (DBPs) in natural waters treated with ozone and chloramines. Experimental tasks are designed for the simultaneous study of C. parvum oocyst inactivation and selected DBP (bromate, formaldehyde, and cyanogen halides) formation in natural waters treated with ozone and chloramines in various reactor configurations. An integrated predictive model will be developed, calibrated with experimental results, used to determine optimum process design, and verified in full-scale systems using fluorescent-dyed polystyrene microspheres as surrogate indicators for C. parvum oocysts.

Development of Ozone Contactor Model for Bromate Formation and C. parvum Oocyst Disinfection
B. J. Mariñas,* R. A. Minear,* J.-H. Kim
Montgomery-Watson, Inc.; American Water Works Association Research Foundation

The objective of this project is to develop a model that will allow the overall optimization of ozone contactor design and operating mode to achieve maximum C. parvum oocyst disinfection efficiency and minimum bromate formation with natural waters of various qualities containing low bromide concentrations. Ozone contactors are commonly comprised of one or more transfer chambers in which ozonated gas is diffused into water followed by several reactive chambers where additional inactivation and corresponding disinfection by-product (DBP) formation takes place. Modeling the disinfection and DBP formation efficiencies taking place in these constactor chambers requires taking into consideration hydrodynamics, gas transfer, and reaction kinetics.

Optimizing Control Strategies for Disinfection By-Products for Small Water Supplies Using Ozone as an Alternative Disinfection Process
R. A. Minear,* M. Smith, J. Cochran
Illinois Water Research Center; U.S. Geological Survey

The presence of bromide in many waters (especially groundwaters) leads to bromate formation when treated with ozone. Bromate regulation is now being proposed at a maximum contaminant level of 10 mg/L. Various control strategies that reduce bromate formation in ozone treatment lead to increased formation on brominated organic disinfection by-products. Variations in treatment conditions designed to control bromate concentrations in treated water can actually increase the TOBr concentrations. It also appears that the properties of natural organic matter in a given water influences the outcome. How these properties influence pathway dominance and how this in turn affects specific bromate minimization remain to be elucidated and are the focus of this research.

Direct Comparative Genotoxicity Assessment of Disinfection By-Product (DBP) Mixtures in Drinking Water Generated from Different Disinfection Processes
R. Minear,* M. Plewa,* S. Echigo
American Water Works Association Research Foundation

A study is proposed in which a novel assay is coupled with a more traditional assay to evaluate the genotoxicity of disinfection by-products (DBPs) and DBP mixtures. Chlorine (the traditional water treatment disinfectant), ozone (an alternative disinfectant/oxidant), and the sequence of ozone plus chlorine in addition to chloramination and chlorine dioxide treatment methods will be examined. Simple and complex DBP mixtures, produced from chlorination, ozonation, or coupled ozonation/chlorination and chloramination and chlorine dioxide treatments, will be created from a NOM standard (SRFA) containing water. The assays will be augmented by a database created to represent an occurence assessment of regulated/soon-to-be regulated DBPs.

Genotoxicity and Occurrence Assessment of Disinfection By-Product Mixtures in Drinking Water
R. A. Minear,* M. J. Plewa,* S. Echigo
U.S. Environmental Protection Agency, R825956-01

Representative drinking water disinfection by-products (DBPs) will be produced from organic matter isolated from a series of representative source waters used for drinking water supplies using both chlorination and ozonation in laboratory reactors under a range of disinfection conditions. Selective conditions will allow differential evaluation of brominated DBPs via ozonation of bromide-containing waters and also provide information on the relationship of toxicity to DBP molecular weight. Bulk DBPs will be analyzed for toxicity and mutation induction in S. typhimurium using a suspension test ± S9. The same DBPs will be analyzed with transgenic Chinese hamster lung cells ± S9 using the single cell gel electrophoresis (SCG) method to detect direct genomic DNA damage.

Bromate Formation and Control during Ozonation of Low-Bromide Waters
R. A. Minear,* B. Mariñas,* M. Urban
Montgomery-Watson, Inc.; American Water Works Association Research Foundation

An orthogonal matrix of experiments is directed at determining the critical factors in minimizing the formation of bromate in low-bromide-containing waters. Variations in temperature, pH, ammonia content, and a radical scavenger, ethanol, are being studied for a range of ozone doses and contact times that coincide with requirements for the inactivation of C. parvum oocysts. The associated disinfection by-products resulting from the treatment and water quality variations are being examined as well.

Novel Characterization of Humic Substances and Their Role in the Behavior of Environmental Toxic Substances Using HPLC/MS/MS
R. A. Minear,* M. J. Plewa*
National Science Foundation, International Cooperative Research

The underlying hypothesis of the overall proposed cooperative research effort is that NOM and humic substances as a subset affect the environmental toxicology of anthropogenic compounds though complex interactions that effect membrane transport and mechanisms of toxicological reactions. The three-year project involves a series of composite objectives. These overall objectives complement parallel work in the laboratories of Minear and Plewa. They also provide translation of capabilities in the University of Illinois laboratories to the researchers in Kyoto, Japan, while offering the principal investigators an opportunity to explore new research dimensions.

Molecular Weight Separation and HPLC/MS/MS Characterization of Previously Unidentified Drinking Water Disinfection By-Products
R. A. Minear,* S. Barrett,* X. Zhang
U.S. Environmental Protection Agency, R826834-01

A study is proposed in which new approaches are to be developed for better characterizing disinfection by-product molecular weight profiles by using tandem mass spectrometry (MS/MS) techniques. A prerequisite to making such procedures meaningful is the development of preseparation procedures that will simplify the mass spectral data. The MS/MS system has its own separation capabilities. The proposed work is directed at enhancing these capabilities for complex DBP mixtures with preselection by molecular weight separations using ultrafiltration membranes or size exclusion chromatography.

Integrated Approach for the Control of Cryptosporidium parvum Oocysts and Disinfection By-Products in Drinking Water Treated with Ozone and Chloramines
R. A. Minear, B. Mariñas,* H. Lei
U.S. Environmental Protection Agency

In conjunction with the modeling work of Professor B. Mariñas' group, there will be an extensive evaluation of how the combined disinfection operations affect the disinfection by-products qualitatively and quantitatively and how this is related to water characteristics.

Cost-Effective Monitoring Design for Intrinsic Bioremediation
B. S. Minsker,* A. J. Valocchi, P. M. Reed
Illinois Water Resources Center; U.S. Geological Survey

Active remediation of the thousands of leaking underground storage tanks (USTs) in the U.S. is expected to cost billions of dollars. Intrinsic bioremediation has recently gained attention for reducing costs associated with remediation of UST sites. The technology involves coupling on-site monitoring and regulation with natural biodegradation of contaminants. The controlling factor in determining the cost-effectiveness of intrinsic bioremediation is the expense of long-term monitoring to ensure the protection of human health and the environment. In this project, we are developing a model for designing cost-effective monitoring plans using a genetic algorithm and a biodegradation simulation model called RT3D.

Survey of Models Relevant to Sediment Contamination in Water Bodies
B. S. Minsker,* M. García, E. Herricks, C. Rehmann, C. Werth, P. Reed, J. Schwartz, E. Bretz
E. I. du Pont de Nemours & Co.

Management of sediment contamination in water bodies is a highly complex problem, involving numerous physical, chemical, and biological processes operating in a multitude of environmental settings. To aid in developing and evaluating cost-effective strategies for sediment management, efficient and effective predictive tools are needed. The objective of this project is to identify available computer models and to evaluate those models that might be most appropriate for managing potential sediment management scenarios. Once available models are evaluated, recommendations will be made regarding the need for development/modification of sediment management tools in future project(s).

Research and Educational Advances in Optimal Groundwater Remediation Design
B. S. Minsker,* D. Goldberg, F. Saied, Y. Liu, E. Bretz, B. Briskin
National Science Foundation, BES 9734076 CAREER

An optimal control model for aerobic in situ bioremediation design has been developed, but the computational effort associated with solving the model prohibits solution of field-scale, heterogeneous problems. Multiscale optimization methods and a hybrid genetic algorithm are being developed to improve performance and capabilities of the model. The research will be integrated with education through development of graphical user interfaces, an educational game, and a new graduate course on coupled optimization and simulation modeling to teach students the complexities associated with developing and applying such models.

Use of Molecular Techniques to Evaluate Causes and Control of Foaming in Activated Sludge Systems
L. Raskin,* F. L. de los Reyes
National Science Foundation, BES 9733826

The formation of a viscous, stable foam layer on activated sludge aeration basin and final clarifier surfaces is a common problem for the activated sludge industry that has been linked to the presence of filamentous bacteria. This research will develop oligonucleotide probes targeting the ribosomal RNA of filamentous microorganisms, which can be used as diagnostic tools to evaluate foaming problems without the prior cultivation of bacteria. In addition, the research will test the performance of laboratory-scale activated sludge systems equipped with selectors. Population shifts of foam-causing microorganisms will be followed before, during, and after foaming episodes in these systems using ribosomal RNA-targeted oligonucleotide probes and related to operating conditions and system performance.

Molecular Probes for Anaerobic Wastewater Treatment Process Evaluation
L. Raskin,* D. Zheng
U of I Center for Advanced Study; Campus Critical Research Initiatives Program

The research will focus on anaerobic wastewater treatment systems in which the formation and stability of "granules" or conglomerates of microorganisms is critical for good performance. Methods for studying granule formation and stability will be developed by combining physical methods that determine granule hydrophobicity and liquid surface tension with ribosomal RNA-based identification and quantification techniques. In addition, operating strategies that reduce start-up time and improve per-formance will be evaluated in laboratory-scale anaerobic bioreactors.

Solution-based Hybridizations for Rapid Identification and Quantification of Anaerobic Microbial Assemblages
L. Raskin,* R. Gaskins, R. Mackie, M. Mau, K. Hristova, D. Zheng, R. Aminov
Campus Critical Research Initiatives Program

Current molecular microbial characterization methods are limited because they require immobilization of target nucleic acids on solid supports. This immobilization step precludes automation. This project will develop novel molecular methods that are based on the generation of a fluorescent signal in solution, eliminating the immobilization step required in current molecular techniques. First, we will focus on the development of solution-based hybridizations for qualification of anaerobic microbial populations. Then, we will evaluate the utility of this technology in separate biological reactor systems inoculated with samples from two distinct environments sharing microbial and metabolic features: anaerobic wastewater treatment systems and the mammaliam digestive tract.

Swine Waste Processing Using Anaerobic Sequencing Batch Reactors and Nutrient Recovery Systems
L. Raskin,* L. Angenent
Illinois Council on Food and Agriculture Research (C-FAR)

The anaerobic sequencing batch reactor (ASBR) is a new biological process for the conversion of organic wastes to biogas. The technical feasibility of ASBRs to stabilize swine waste has been demonstrated at Iowa State University. This research will evaluate possibilities to further reduce capital and operating costs of ASBR systems and to create an alternative added value to the system. The research will focus on seeding ASBRs with different sludges to reduce start-up periods, recovering nutrients from ASBR effluent, and reusing ASBR effluent as flush water.

Microbial Characterization for the Anaerobic Aquatic Metabolism Study Required for Herbicide Registration
J. J. Crawford,* L. Raskin,* F. W. Simmons
University of Illinois

Anaerobic herbicide fate is important to cropping practices and herbicide use in soils. The Anaerobic Aquatic Metabolism Study, EPA Protocol N-162-3, is the sole evaluation of anaerobic herbicide fate required for herbicide registration. This study is not representative of environmental conditions; therefore, results do not represent herbicide behavior in anaerobic soils. This research involves characterization of microbial communities in flooded anaerobic soils using molecular biology techniques in herbicide treated and untreated soil microcosms. The EPA protocol is compared with two alternative protocols in order to put forth a protocol that more accurately represents flooded soil conditions.

Molecular Probe Technology for Studying Biofilms in Drinking Water Distribution Systems
L. Raskin,* V. L. Snoeyink, B. J. Mariñas, F. Bichat, S. Meintser
U.S. Environmental Protection Agency, CR-826461010

Biofilms are complex structures of microorganisms immobilized on a surface and embedded in an extracellular organic polymer matrix. Pathogens may grow or may be entrapped in biofilms that develop in drinking water distribution systems. Molecular techniques are being developed to detect and assess the viability of pathogens and indicator organisms in water samples from distribution systems. In addition, molecular techniques are being developed to visualize these microbes in biofilms and to study the microbial populations that constitute the biofilm. Pipes taken from existing distribution systems are being used to build laboratory-scale systems that simulate distribution systems.

Development of Carbon-based Adsorbent from Waste Tire-Paint Sludge Mix for Control of Gasoline Emissions from Automobiles
M. Rostam-Abadi,* M. J. Rood,* G. Lehmann, D. Ramirez
Campus Office of Solid Waste Research; Illinois Department of Energy and Natural Resources, IDCCA 96-206-307; Ford Motor Co.

There is increased interest to remove gasoline vapors from air that is emitted from motor vehicles. One possible method to capture gasoline vapors before they are emitted to the atmosphere is with low-cost carbonaceous adsorbents. This project is developing and evaluating low-cost carbonaceous adsorbents made from waste tires and paint sludge mixtures that can be used in existing automobiles' activated carbon canisters for gasoline vapor control. Development of such new adsorbents will allow for a new market for waste tires and paint sludge, recycling of the materials back to the automotive industry, and improved ambient air quality.

Influence of Aerosol Particles on Climate at a Mid-Latitude Continental Site
M. J. Rood,* P. Kus, K. Winter
National Oceanic and Atmospheric Administration, COM NA56 GP0455

Concerns about ambient aerosol particles effecting global warming need to be resolved in order to develop a better understanding about atmospheric changes over time periods of years to decades. Real-time in situ measurements of the ambient aerosol scattering coefficient and its dependence on wavelength of light, particle size, and composition have been occuring about 15 km southwest of Champaign, Ill. This site is ideal because it is representative of the region and it experiences air masses from a wide range of sources. This research will provide data for global-scale numerical models that predict the influence of global change by atmospheric aerosol particles.

Influence of Aerosol Light Scattering on Climate at a Remote Marine Site (ACE-1)
M. J. Rood,* C. Carrico
National Science Foundation, ATM-9418376, ATM-9418376 REU

There are numerous aspects of the global environment that need to be better characterized to better understand how our environment is changing. The effect of aerosol particles on the atmospheric radiative energy balance at a remote marine site is one area that needs better characterization. The primary objective of this research is to characterize climatically relevant ambient aerosol properties at Cape Grim, Tasmania. Cape Grim is an ideal location to study a southern hemispheric remote marine environment. Information gained from such research can provide valuable input to currently existing global climate models, which in turn can provide better insight into how to develop policies related to global warming.

Dependence of Ambient Aerosol Light Scattering on Controlled Relative Humidity at Bondville, Ill.
M. J. Rood,* K. E. Winter, P. Kus
National Oceanic and Atmospheric Administration, COM 40BNR801144

Global-climate models have shown that ambient aerosols resulting from human-related activities have the same degree of influence on climate but of opposite sign when compared to greenhouse gases. Uncertainties in the climate models need to be reduced so that results from these models can be used to formulate better policies related to human activities and climate change. Ambient aerosols are being measured on a continuous basis at Bondville, Ill., a polluted regional site, at carefully controlled relative humidity conditions to provide inputs with less uncertainties into these climate models.

Evaluation of Uncertainties in Satellite Retrievals of Aerosol Forcing Using In Situ Measurements at the Surface
M. J. Rood,* J. A. Ogren,* D. S. Covert,* P. Sheridan,* P. Kus
National Aeronautics and Space Administration, COM 40RANR900971

The accuracy of climate-change predictions is closely linked to the availability of measured aerosol parameters associated with direct radiative forcing. Derivation of results describing aerosol radiative forcing from satellite observations requires assumptions about the properties of the aerosol particles. Tropospheric aerosol properties measured under in situ conditions and at regional aerosol monitoring stations will be used with the NASA aerosol climatology processing facility to test the sensitivity of candidate satellite data retrieval algorithms to observed variations of aerosol properties. Results from this research will allow better quantification of uncertainties associated with satellite retrievals of aerosol properties.

Removal and Recovery of Organic Vapor Emissions by Carbon Fiber Cloth Adsorber-Cryogenic Condenser
M. J. Rood,* P. D. Sullivan, M. Lordgooei
U.S. Army Construction Engineering Research Laboratories, DACA88-98-D-0005-01

Hazardous air pollutants need to be removed from gas streams before they are emitted to the ambient environment as a result of the Clean Air Act Amendments of 1990. A new activated carbon fiber-cloth adsorber is under development for integration with a condenser to capture, concentrate, and then recover dilute hazardous air pollutants in gas streams for reuse. Laboratory experiments and economy indicate that select hazardous air pollutants can be removed from gas streams for reuse in a cost-effective manner.

Biological Treatment of Hazardous Air Pollutants and Other Related Compounds at a Pharmaceutical Wastewater Treatment Plant
M. J. Rood,* R. Sanford,* L. Raskin,* J. Chee-Sanford, J. Li
Abbott Laboratories, Inc.

Manufacturing of pharmaceutical products produces waste streams that need treatment before they are discharged to the ambient environment. Of particular interest is the wastewater that can contain hazardous air pollutants (HAPs). Pending regulations developed by the USEPA will require 95% by mass removal efficiency of the HAPs by biological treatment. Material balances of specific compounds at wastewater treatment facilities are needed to determine the removal efficiencies of HAPs and other related compounds. This project is completing detailed material balances for HAPs and related compounds at a pharmaceutical wastewater treatment plant to determine the biological removal efficiency of those pollutants.

Aerosol Light Scattering and Related Properties at Climate-sensitive Sites
M. J. Rood,* C. M. Carrico, M. Mulhern
National Science Foundation, ATM 96-10051, ATM 96-10051 REU

The Aerosol Characterization Experiment (ACE-2) includes measurements taken from ground, ship, satellite, and aircraft to characterize the influence of European and North African aerosol on climate. The primary objective of this research is to provide in situ rapid-response experimental and modeled results describing the ambient aerosols' light-scattering properties at Sages, Portugal, as part of ACE-2. Results from this research can serve as input to global-scale climate models that predict radiative forcing due to anthropogenic aerosol. These predictions can then be used to establish policies related to anthropogenic aerosols and their effects on climate.

Mercury Vapor Removal from Simulated Flue Gases with Illinois Coal-derived Activated Carbon
M. Rostam-Abadi,* S. G. Chen,* M. J. Rood,* H. C. Hsi
Electric Power Research Institute; Illinois Clean Coal Institute

There is a concern that mercury emissions into the ambient environment from select types of combustion processes may cause health effects. This project is developing methods to produce new materials to separate and remove mercury from flue gas streams generated during the combustion of coal. Select low-cost materials are processed and then characterized with respect to their chemical and physical properties before they are used to remove mercury from flue gas streams. Bench-scale testing and pilot-scale testing of these new materials are important components of this research.

Use of Activated Carbon for Chemical and Biological Reduction of Bromate
V. L. Snoeyink,* M. J. Kirisits
KIWA, The Netherlands

Bromate, BrO¯3, is formed by reaction of ozone with bromide during water treatment and is not removed through conventional means. It is a suspected human carcinogin, so we are especially interested in removing it before drinking water distribution. Activated carbon processes show good potential for treating low concentrations of this compound by both chemical and biological means. This project is focused on development of the catalytic properties of activated carbon so that this compound can be removed by chemical means, as well as techniques to develop biofilms that will catalyze its reduction.

Taste and Odor Control of Chicago, Ill., Water Supply
V. L. Snoeyink,* T. E. T. Gillogly
Chicago (Illinois) Department of Water

The objective of this research is to determine the processes most suitable for taste and odor removal from Chicago's water supply and to determine the best way to optimize the operation of these processes. A dominant compound that causes odor in Chicago's water is MIB. The best ways to apply powdered activated carbon (PAC) and granular activated carbon (GAC) at Chicago to remove this compound to below its threshold odor concentration of 5 ng/L are being studied.

Powdered Activated Carbon in Floc Blanket Reactors Combined with Ultrafiltration
V. L. Snoeyink,* C. Campos, Q. Li
Lyonnaise des Eaux-Suez, France

The objective of this research is to determine the efficiency of the floc blanket reactor (FBR)-PAC-ultrafiltration (UF) process for the removal of both natural organic matter and trace organic contaminants. Previous research has shown the effectiveness of the PAC-UF process. By recycling the PAC from the PAC-UF part of the process to the floc blanket reactor, we can reduce the dosage of carbon required to achieve a certain effluent concentration by 30% to 50%. The reason for the decreased dosage is the larger amount of organic matter that can be adsorbed in the FBR. A mathematical model of the process has been developed to predict performance for both TOC and trace compound removal. Future work will involve testing different surface waters and different carbons, and modification of the model to make it more robust.

Effect of Activated Carbon Pore Structure and Surface Chemistry on the Adsorption of Trace Compounds from Natural Waters
V. L. Snoeyink,* C. Pelekani
University of Illinois

Several different types of activated carbon and activated carbon fibers with a wide range of pore size distributions and surface chemistries are used to study competitive adsorption. The objective is to determine the relative importance of the physical characteristics of the pores in comparison to the surface chemistry of the activated carbon for removal of compounds, such as atrazine and earthy musty-odor-causing compounds, that are found in drinking water supplies. The research is expected to lead to a better understanding of the desirable properties of activated carbon for trace compound removal.

Development of Red Water Control Strategies
V. L. Snoeyink,* P. Sarin, D. Lytle, K. Jim, J. Bebee
American Water Works Association Research Foundation

The objective of this research is to determine the mechanisms of red water production in drinking water distribution systems and to develop strategies for controlling this problem. The study involves use of small-scale pipe loops in the University of Illinois laboratory to which water with different qualities is applied. Important parameters are pH variation, neutral salt concentration variation, and the concentration of inhibitors, such as orthophosphate. Short-term tests are being developed to show how existing layers of corrosion products on pipes react to produce red water, and procedures for chemically conditioning the scales so that red water does not form will be established.

Characterization of Scales in the Chicago Water Distribution System
V. L. Snoeyink,* P. Sarin, K. Jim, J. Bebee
City of Chicago, Ill.

The objective of this project is to determine the chemical composition of scales that have been found on cement-mortar-lined distribution pipes, to determine the effect of these scales on the hydraulic properties of the distribution system, and to determine ways to control the formation of this scale. The approach involves use of energy dispersive spectroscopy to determine elemental composition and nuclear magnetic resonance spectroscopy to determine chemical structure. A pipe-loop system will also be used to determine how the scales form and how they can be prevented.

Removal of Bromate and Perchlorate in Conventional Ozone/GAC Systems
V. L. Snoeyink,* L. Raskin,* S. Liang, M. J. Kirisits, J. Brown
American Water Works Association Research Foundation

The objective of this project is to show how conventional ozone/GAC systems can be modified and operated to give good removal of microgram-per-liter concentrations of bromate and perchlorate. Removal by ion exchange, catalytic reduction, and biological reduction will be investigated. Biological reduction holds the most promise and will be investigated most thoroughly. After an extensive series of laboratory tests, a pilot-plant study of the process will be undertaken at the Metropolitan Water District of Southern California.

Acetate and Succinate as Electron Donors for Reductive Dechlorination-Alternatives to H2
R. A. Sanford,* A. R. Swanson, F. Loffler
University of Illinois; Georgia Institute of Technology

Recently it has been suggested that H2 is the most important electron donor for the reductive dechlorination of tetrachloroethene (PCE) by dechlorinating anaerobic bacteria. The objectives of this project are to demonstrate the importance of alternative electron donors for dechlorination, such as acetate and succinate. It has been found that the PCE-utilizing strain BB1 is unable to use H2; however, both acetate and succinate are readily used by this culture. The 2-chlorophenol dechlorinating strain 2CP-C also uses acetate. This research will identify threshold concentrations for these electron donors and will provide important data for designing anaerobic bioremediation processes for groundwater.

A Comparison of Hydrogen Threshold Concentrations Associated with Electron Acceptors Used by Strain 2CP-C
R. A. Sanford,* S. Oh
University of Illinois

H2-threshold concentrations are used as indicators of the predominant electron acceptor being used in the groundwater. This is only true if H2 is a universal electron donor. The objective of this project is to compare threshold concentrations in the presence and absence of acetate associated with the utilization of O2, NO3, fumarate and 2-chlorophenol by bacterial strain 2CP-C. It is expected that the H2-threshold concentrations will be determined by the available energy associated with the reduction of the different electron acceptors. The presence of acetate oxidation, however, could artificially raise the threshold concentration by leading to H2 generation.

Competitive Sorption of Volatile Organics in Model and Natural Solids
C. J. Werth,* J. Li
National Science Foundation, BES 9803563

Laboratory studies have been conducted to characterize mass transfer limitations in the subsurface. In most cases, mass transfer rates for single sorbates were measured in an attempt to characterize mass transfer limitations in the field. However, mixtures of volatile organic chemicals (VOCs) are often present in the field, both as the source of contamination and as transformation products from biodegradation. The objective of this project is to determine the effects of chemical mixtures on mass transfer in geosorbent (i.e., soil and sediment) aggregates.

Spatial and Temporal Characterization of Dense Nonaqueous Phase Liquids in Porous Media Using Magnetic Resonance Imaging
C. J. Werth,* A. Aragon, C. Knutson
National Science Foundation, BES 97-33428 CAREER

Accurate characterization of nonaqueous phase liquid (NAPL) dissolution requires a mechanistic understanding of the complex factors affecting the NAPL-water interfacial area across which mass transfer occurs. Prior experimental techniques have not been able to resolve these factors, resulting in phenomenological mass transfer coefficients that are constrained by experimental conditions. The objectives of this project are: (1) to determine the effects of interstitial water velocity on the effective NAPL-water interfacial area, (2) to determine the effects of pore and NAPL characteristics on the effective NAPL-water interfacial area, and (3) to predict time-dependent NAPL dissolution in natural porous media.

Effects of Temperature on NAPL Dissolution Using Micromodels
C. J. Werth,* C. Chomsurin
University of Illinois

The objective of this study is to improve fundamental understanding of dense nonaqueous phase liquid (DNAPL) dissolution in natural porous matrices and the associated effects of temperature. To accomplish this objective, we will use micromodels to measure DNAPL entrapment and dissolution as a function of temperature. Micromodels are a two-dimensional representation of a porous matrix etched into a silicon wafer and geochemically modified by the addition of an oxide surface.

Durability of Wood-based Granular Activated Carbon
C. J. Werth,* B. Grens
Pica USA; Westvaco Corp.

Wood-based granular activated carbon (GAC) has been successfully used in place of bituminous coal-based GAC in both pilot-scale and full-scale filter applications. However, many industry professionals in the United States feel that wood-based GAC degrades easily during repeated backwash cycles. The objective of this project is to determine the effects of backwashing on wood-based GAC physical characteristics and particle loss in comparison to bituminous coal based GAC.

Effects of Concentration and Equilibration Time on Contaminant Transport
C. J. Werth,* K. Hansen
University of Illinois

Previous investigators have shown that the magnitude and rate of slow desorption are affected by both the highest concentration sediments are exposed to and the equilibration time. In the subsurface, contaminant concentrations are variable and thus, groundwater sediments are exposed to varying concentrations for varying amounts of time. The objective of this study is to determine the effects of concentration and equilibration time on tailing behavior in a groundwater plume.