Nitrocellulose (NC) wastewater is a byproduct of the manufacture of military gun propellants. The purpose of this work is to characterize the physical and chemical nature of NC wastes, and to analyze the membrane-fouling potential of NC wastes using static membrane adsorption tests. Candidate membranes identified in these tests will be further studied in batch ultrafiltration tests. Membrane fouling will be examined under conditions of different transmembrane pressure, pH, and calcium concentration. These data will be compared with numerical modeling of membrane fouling by particulate and organic material.

In this project, we hypothesize that continuous pilot ultrafiltration systems can be characterized hydraulically by equivalent pumps, pipes, valves, and minor and major energy losses, and that the system pressure, flow, and fouling dynamics can be simulated using only a few experimentally determined coefficients. Once the fouling phenomena have been calibrated, then the model can be used to simulate any type of operational schedule of filtration cycles, backflush cycles, and even membrane cleaning. Thus an economic optimization of the system can be performed in terms of optimal filtration, backflush, and cleaning cycles.

Mathematical modeling will be used in the first problem to predict the rate of deposition of foulants within membrane pores. The modeling will be supplemented with measurements of humic material adsorption on membranes, as well as measurement of membrane charge, hydrophobicity, and surface roughness. In the second problem, aluminum precipitation kinetics were combined with micromixing models to predict the effect of mixing on coagulant precipitation and the structure of floc. The importance of the scale of the flocculation process is being investigated through experiments and mathematical simulation, and new methods for connecting flocculation rate to fluid mechanics are being developed.

A fully automated ultrafiltration pilot plant will be constructed and set up at a small Illinois water producer. Operational data from the pilot will allow judgments on the expected membrane performance and operational and cost requirements for this water treatment system. Performance will be judged mainly on the ability of the system to meet new regulations on drinking water quality, in particular, higher standards on turbidity and microbial contamination. Operational performance will be based on the consideration of membrane flux and backflushing and cleaning frequency. An extensive cost model will not be developed, but typical costs for example systems will be developed. Finally, a system for remotely monitoring and operating the pilot and recording water quality data will be tested.

The decay of chlorine concentration in drinking water supply systems is modeled by considering heterogeneous and homogeneous chlorine reactions and simple one-dimensional transport. Corrosion and batch chlorine decay rate data are used to establish bounds on reactions rates, and simulations are performed to estimate reaction- and mass transport-limited consumption of chlorine in pipe systems. The simulations are compared with field measurements of actual chlorine concentration in French water distribution systems. The simulations will help in understanding the most significant parameters in the chlorine decay problem and what type of experimental data are most critical for predicting water quality in drinking water distribution systems.

Methods must be developed to measure bubble size distributions, liquid circulation, and mass transfer in new generation air-lift bioreactors. These data can be used to verify models of fluid mechanics and mass transfer, which will in principle allow the simulation of different bioreactor designs and an optimization of the design based, for instance, on oxygen mass transfer. Other design issues can be explored, such as the elimination of reactor dead zones and regions of high particle shear. Photography/digital image analysis will be used to the characterize bubble size distributions, which will be used as one input in the mathematical simulation of the fluid mechanics and mass transfer in the reactor. Tracer techniques will be used to characterize bulk circulation in the air-lift reactor.

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.

Trichloroethylene is the most frequently encountered chlorinated solvent in contaminated groundwater. With anaerobic bioremediation, trichloroethylene can be reductively dechlorinated to ethylene and ethane, both of which are nonhazardous. However, the rate-limiting step is reduction of vinyl chloride, which is even more hazardous than trichloroethylene. One way to ensure complete removal of vinyl chloride is to follow the anaerobic phase with aerobic treatment. Since at least partial reduction of vinyl chloride to ethylene and/or ethane is likely, this project is examining the use of these compounds as primary substrates to sustain aerobic cometabolism of vinyl chloride. Doing so will eliminate the need for adding an exogenous electron donor.

Dichloromethane (DCM) is one of the most commonly used chlorinated organic solvents. Aerobic biotreatment of contaminated water has been demonstrated; however, application to highly concentrated wastes has been hindered by the difficulty of delivering oxygen and volatilization of DCM. The objective of this project is to develop a high-rate biological method for treating DCM-contaminated waste streams using denitrifying bacteria. A recently isolated strain of Acinetobacter that biodegrades DCM both aerobically and under denitrifying conditions will be used. Application to treatment of industrial wastewater containing a significant fraction of DCM will be evaluated, including wastes from pharmaceutical manufacturing and paint stripping.

Treatment of wastewater containing nitrocellulose (NC) is a significant hazardous waste challenge for the U.S. Army. Physical and chemical methods of removing NC are effective but costly. Biological methods are not in use because NC is generally regarded as refractory. However, recent work by Freedman et al. determined that a reduction in the percent nitrogen content of NC does occur under methanogenic conditions, resulting in a nonexplosive product. The purpose of this project is to examine the effect of various electron donors on NC reduction under methanogenic and sulfate-reducing conditions, and to construct a mass balance on the fate of nitrogen derived from NC.

Disposal of nitrocellulose (NC) fines generated during the manufacture of this explosive compound is a significant hazardous waste problem. It has been known for many years that NC decomposes slowly during storage, resulting in a decrease in its percent nitrogen content. The objective of this study is to quantify the effects of temperature, time, and pressure on the rate of denitration, so that a pilot-scale facility for treating NC by thermal decomposition can be designed. In addition, the composition of off gases is being measured, in order to evaluate the options needed for treatment of NO_x emissions.

Belt filter press dewatering is one of the most common methods of concentrating solids in water and wastewater sludges. Nevertheless, very few bench-scale tests have been developed to directly measure the performance of belt filer presses. The objective of this study is to evaluate a belt press simulator that recreates the forces applied to a sludge cake in a full-scale press. Comparisons are being made to full-scale units using sludges from a variety of wastewater treatment plants. The simulator is also being tested for its ability to predict optimum polymer dose and type.

Increasing attention is being paid to urban runoff effects on receiving system habitat and biota. The altered flood hydrographs produced by urbanizing watersheds change habitat conditions in addition to delivering increased contaminant loading to streams. Mitigation of urban runoff effects is possible, but designs must be developed in a watershed context. This research is directed to the exploration of rational, natural design practices to minimize the damage of urban runoff in streams. Combinations of retention to alter urbanized area hydrographs and instream habitat improvements are being evaluated to identify the most suitable management strategies for urban runoff control.

This research will develop a database that provides a regional perspective on the frequency and exposure of contaminants common to wet-weather events in watersheds with different levels of development. The research will also provide a test system selection procedure to identify bioassays that meet specific regional or other needs for testing to assess the effect of wet-weather events. Further, field studies are proposed to validate the test system selection procedure in both fresh water and marine systems. In total, the research will make effective use of existing protocols adapted to regional, and in some cases site-specific, conditions in the United States while addressing the need to develop toxicity data appropriate to the character of wet-weather events.

The contamination of stream sediments with heavy metals, the dynamics of these sediments, and the mitigation and/or remediation of contaminated sediment are critical water resources problems in Illinois and throughout the United States. Heavy metal contamination is a particular problem in streams draining urban and industrialized areas. The environmental consequences of this contamination are the loss and degradation of habitat and damage to plants and animal life in and around streams. This research project addresses the short-term and long-term fate of heavy metals moving through stream systems by focusing on the local erosional/depositional processes. The study will lead to a better understanding of the physical processes controlling contaminant dispersal/dilution at the network scale and the potential impact of heavy metals on stream biota.

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.

Small invertebrate organisms ( Daphnia and Ceriodaphnia ) are regularly used in acute and chronic toxicity testing. The endpoint of these tests is mortality, although other measures (e.g., reproduction) can also be used. Kerin Umwelt Technique has developed the Daphnia Monitor, which allows continuous assessment of the phototactic response of a range of zooplankton species. Kerin has lent this instrument to the University of Illinois and it is being used to evaluate its flexibility with regard to species (e.g., Daphnia vs. Ceriodaphnia ) and the utility of the instrument in monitoring episodic event effects.

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, stormwater wetlands are artificial systems that may or may not respond as natural wetlands to pollutant loading. This research is intended to explore the response of constructed stormwater wetlands to dynamic loading typically associated with urban stormwater runoff. The objective of initial studies is the use of experimental wetlands to identify fundamental processes associated with water quality control in these modified ecosystems.

The Department of Defense has established a policy for the abatement of lead-based paints in family housing and related structures. Removal of these paints produces a residue with a high-lead content that must be disposed of as a hazardous waste if leaching tests result in lead concentrations greater than 5.0 mg/L. These leaching tests do not address the long-term liability that may result from the movement of this toxic metal from the landfill. Laboratory studies are being conducted to evaluate this long-term effect. Batch tests using paint chips removed from military housing are being conducted to determine the equilibrium concentration of soluble lead resulting from the different test conditions.

This research will contribute to a better understanding of how airborne particulate matter affects regional visibility and global climate. Laboratory experiments, field measurements, and computer modes will be used to investigate how airborne particles scatter and absorb sunlight and thus affect the amount of light transferred through the Earth's atmosphere. The data from the experiments will be used to test the accuracy of the computer models. Once the computer models are verified, they will be used to assess the probable success of air pollution control strategies designed to minimize changes in radiative transfer.

The influence of aerosol particles on global climate is not well understood. This influence can be better quantified by studying aerosol particles and their abilities to scatter light. In this research, two parallel efforts of numerical modeling and experimental work will link chemical and physical characteristics of the atmospheric aerosol with atmospheric optical properties. The two thrusts of the research project will be brought together in using the experimental aerosol data as inputs to the numerical models to predict radiative properties of the atmosphere. These predicted values will be compared to measured radiative parameters to verify the numerical models.

The composition and structure of aerosol particles affect their growth characteristics and light-scattering efficiencies. In this experimental research, interactions are studied between water vapor and airborne particles consisting of a soluble (e.g., salt) or insoluble (e.g., carbon black) core and an outer layer of organic materials. Coated and inhomogeneous particles are also studied to determine the effect that coatings and inhomogeneities have on the light-scattering phase function of the particle. A further effort is to quantify the growth of liquid droplets and ice crystals by the scavenging of gases and other small particles.

The challenge of achieving good air quality in the enclosed environment of a vehicle cabin is the focus of this project. This research involves determination of the adsorption capacities of Ford-provided activated carbons and a sample of activated carbon fibers. The adsorption capacities are determined from packed bed breakthrough curves using a mass balance approach. The carbons will be tested at different adsorbate concentrations. Adsorbates of interest include toluene and n-butane. Tests will be carried out at ambient temperature in a dry air stream and in an air stream at 70% relative humidity.

Our main objective is to increase our knowledge of atmospheric aerosols, clouds, and trace gas species to more fully understand their role in environmental change. To do this, we are developing and testing laboratory instruments based on laser diode technologies. These prototype multiple-wavelength laser diode systems will be tested in the lab for their suitability for aerosol and water vapor measurements before being taken to the field where these quantities will be measured in the atmosphere as a function of height. The new systems are robust, compact, and cost efficient and will be the basis for a new generation of instrumentation.

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.

This research will evaluate the feasibility of anaerobic digestion for the treatment of the nonrecyclable fraction of typical U.S. municipal solid waste. The operating conditions of laboratory anaerobic bioreactors will be related to the structure and the performance of the microbial community responsible for the anaerobic digestion. The establishment of such relationships should aid in the determination of the optimal operating conditions of bioreactors designed for the treatment of U.S. municipal solid waste. Ribosomal RNA-based hybridization probes specific for several groups of microorganisms of critical importance in anaerobic digestion will be used to characterize the microbial community structure.

Concerns regarding eutrophication of surface waters have led to an increased attention toward nutrient removal from waste streams. Biological removal of nitrogen and phosphorus can be an efficient and cost-effective nutrient removal strategy. However, a thorough understanding of the microbial mechanisms involved in biological phosphorus removal (EBPR) is lacking. The objectives of this research are (1) to improve our understanding of the link between microbial community structure and performance in EBPR treatment systems and (2) to evaluate the introduction of EBPR on biosolids characteristics. We will study EBPR from milk processing plant wastewater using laboratory-scale activated sludge systems and rRNA probes to follow microbial population dynamics.

Carbon adsorbents have been shown to remove sulfur oxides from flue gas and they also serve as catalysts for reduction of nitrogen oxides. The overall objective of this research is to determine if Illinois coal is a suitable material for production of activated char to simultaneously remove sulfur oxides and nitrogen oxides from flue gas streams. Surface chemistry and physical properties of the coals are controlled to optimize the activated coals' ability to remove sulfur oxides and nitrogen oxides from flue gas streams.

Carbon adsorbents are under development to adsorb natural gas for natural gas storage tanks in vehicles. The feedstock for the carbon adsorbent is waste tires, thereby recycling waste tires while generating a marketable material that can then be used in vehicles. The waste tires are microengineered through pyrolysis, activation, and pore structure modification to generate carbon molecular sieves with appropriate properties to efficiently adsorb natural gas at pressures less than 35 atm.

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 will occur about 15 km southwest of Champaign, Ill. This site is ideal because it is exposed to freshly formed aerosol particles 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.

Aerosol particles have the potential to influence global change by scattering and absorbing light as it radiates through the atmosphere. The ability of particles to scatter and absorb light depends on the particles' size distribution and composition. This study will allow analysis of chemical composition and particle size distributions of aerosol particles at a mid-latitude continental site. These results will be integrated with real-time light-scattering and absorption measurements to develop a better understanding of the chemical and physical properties of ambient aerosol particles at this site. These results can then be included in numerical models to better evaluate the effects of aerosol particles on global change.

Emissions of select organic compounds into the atmosphere is a problem resulting from toxicity. A method to separate and remove organic compounds from gas streams is under development to remove these organic compounds from gas streams via adsorption. During electrical regeneration of the adsorbent, the organic material will be cryogenically liquified. Such a device will allow reuse of the liquified organic material in the industrial process until more suitable materials are developed.

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.

Compounds such as NO₃ ^- , BrO₃ ^- , and ClO₂ ^- may be associated with the source water supply or may be formed during water treatment and are not removed through conventional means. Activated carbon shows the potential for treating small concentrations of these compounds. This project will focus on development of the catalytic proper- ties of activated carbon so that these compounds can be removed. Special attention will be given to enhancement of the removal mechanisms for point-of-use treatment systems.

The objective of the research is to determine the efficiency of activated carbon for the removal of pesticides from drinking water to meet European standards of 0.1 µg/L for each pesticide and 0.5 µg/L for the sum of all pesticides. Predictions for the performance of powdered activated carbon and granular activated carbon will be made based on kinetic and equilibrium studies and validated by pilot-scale and full-scale experiments. Competitive effects caused by the simultaneous, reversible adsorption of pesticides and background organic matter will be contrasted with fouling effects resulting from the irreversible adsorption of background organic matter.

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 way to apply powdered activated carbon (PAC) at Chicago to remove this compound to below its threshold odor concentration of 5ng/L is being studied. We have also investigated the use of potassium permanganate for this purpose, and we plan to study the use of granular activated carbon (GAC) and other processes for achieving an odor-free water.

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. Future work will involve testing different surface waters for removal of disinfectant byproduct precursors and testing the efficiency of the process for removing specific compounds such as pesticides.

The objective of this research is to investigate the use of fluorescent-dyed polystyrene microspheres as nonbio logical surrogate indicators to assess the efficiency of Giardia lamblia cysts and Cryptosporidium parvum oocysts inactivation with ozone and free chlorine in drinking water. Poly styrene microspheres dyed with various fluorescent chemicals were selected as indicators based on several criteria: simplicity, sensitivity and accuracy of fluorescence measurement, transparency of polystyrene to visible light, similarity of microsphere and parasite cyst/oocyst with respect to size and density, similarity between microsphere fluorescence decay, and cyst/oocyst inactivation rates.

The main objective of this project is to develop a treatment method for one-time permanent removal of lead from the internal surfaces of leaded brass fixtures. This approach is proposed as an alternative to the continuous lead passivation approach currently considered in the Lead and Copper Rule. Brass surfaces are exposed to monodentate (acetate ion) and bidentate (oxalate ion) salts of copper(II). Lead leaching from brass fixture surfaces during treatment is the result of two steps: reaction between interfacial metallic lead and copper(II) and dissolution of resulting lead(II). Oxidation by copper(II) is generally found to be faster compared to dissolution of lead(II).

The objective of this study is to evaluate the effects of Lake Winnebago, Wisconsin, water characteristics on corresponding demand of dissolved ozone under various drinking water treatment conditions. Raw, settled, and filtered water samples are analyzed in bench-scale batch reactors to determine initial fast ozone demand and subsequent slower ozone self-decomposition kinetics. Water quality parameters having an effect on aqueous ozone decomposition kinetics include natural organic matter (NOM), pH, alkalinity, turbidity, and temperature.