Ph.D Members:

M.S. Members:

Members Graduated:

Active Research:

1. Electrochemical Reduction of munition wastewaters:

Three main constituents of munitions wastewater are 2,4 - Dinitro toluene (DNT), 2,4,6 -Trinitro toluene (TNT) and Hexahydro - 1,3,5 - trinitro - 1,3,5 - triazine (RDX). DNT enterswaste-streams during propellant production, whereas TNT and RDX enter waste-streams duringmunitions loading and demilitarization. There are over 1200 sites with explosive contamination,mostly contaminated by TNT, many of which have also contaminated the ground water. BothTNT and DNT are listed as priority pollutants by the USEPA because of their toxicologyhazards. Two common munitions wastewater are 1) propellent wastewater, with typicalcontaminant concentration of 100 mg/L of DNT with 300 mg/L of ethanol and 2) pinkwater,with typical contaminant concentrations of 70 mg/L of TNT and 10 mg/L of RDX. In thisresearch the performance of a pilot scale reactor is being tested for providing the maximumreduction rate for munition wastewaters. Different operating conditions are considered such ascurrent density, presence and absence of dissolved oxygen, ionic strength of the feed and type ofelectrolyte. The tests are conducted with the goal of having a pilot scale reactor tested and readyfor field tests after this task is completed.

2. Removal of MTBE from water by adsorption:

Methyl-t-butyl ether (MTBE) is a semi-volatile compound most often used as a gasolineoxygenate. Due to its widespread use, detectable concentrations have been found in urban air,groundwater, and in surface water. The concentration levels of MTBE in water could be in therange of 200 g/L. The main goal of the research is to remove MTBE from water toconcentration levels below 2 g/L by air stripping and then compare two treatment technologies(activated carbon adsorption and carbonaceous resin) for treating the air to remove MTBE. Thestudy will initially investigate drinking water levels of MTBE (i.e., 200 g/L in water) that resultin typical off gas concentration from an air stripper operating at a 200:1 air-to-water ratio(standard air-to-water ratio for MTBE). Mass transfer considerations for both the air stripper andoff-gas columns (granular activated carbon column and carbonaceous resin) will be defined andmodeled. Following this study, evaluations of operating conditions on removal efficiency will bestudied. The possible conditions of interest include air-to-water ratio, relative humidity, columndepth, off-gas velocity, and water concentration of MTBE. This project is conducted at the USEPA Testing and Evaluation Facility.

3. Development of GC/MS method for detecting low concentrations of PAHs:

A soil media that is previously treated by composting and a sediment that is previously treated byland farming have been further treated by phytoremediation. These test media are contaminatedwith polynuclear aromatic hydrocarbons (PAHs). After the phytoremediation study, thecontamination level of the PAHs is in the ppb range. The scope of work for this research is todevelop an accurate gas chromatography/ mass spectrometry (GC/MS) method that will detectconcentration levels down to 0.01 g/L. Eighteen critical target PAHs compounds areconsidered that represent various chemical structures.

4. Development of a protocol for determining the effectiveness of surface washing agents:

In October 1993 the USEPA published a notice of proposed rulemaking to modify the NationalOil and Hazardous Substances Pollution Contingency Plan (NCP) 40 CFR 300. Changes to theNCP were incorporated into 40 CFR 300 in September 1994. The changes include theestablishment under the Subpart J NCP Product Schedule of a separate category of spill responsechemicals known as surface washing agents (SWAs). Prior to September 1994, a chemical didnot need to meet an effectiveness criterion in order to be listed on the NCP Product schedule. Currently, the USEPA wants to develop a protocol for determining an effectiveness test methodfor SWAs for possible inclusion in future NCP Product schedules. The purpose of this researchis thus to design and evaluate a laboratory test method suitable for inclusion in 40 CFR Appendix3 that can be used to determine the relative effectiveness of SWAs. In order to evaluate the testmethod, quantitative data need to be produced to determine the precision and accuracy of theproposed test method. The USEPA will then conduct a round robin test for the test method todetermine the reproducibility (between laboratories variability) and repeatabilty (within labvariability). This project is conducted at AWBERC US EPA (26 W. Martin Luther King Drive,Cincinnati)

5. Development of endocrine disrupting chemicals quantitation methods for liquid andsludge streams associated with wastewater treatment

The presence of endocrine disruptor chemicals (EDCs) in the aquatic environment has become amajor environmental science and public policy issue. EDCs are suspected of causing toxicityeffects on fish and wildlife populations, including adverse impacts on reproduction anddevelopment. Suspected EDCs comprise a broad spectrum of compounds, including pesticides,hormones, antibiotics, pharmaceuticals, personal-care products, nonionic surfactants, plasticizers,and many other industrial chemicals. The biological effects of these compounds are complicatedby the metabolites and conjugates formed within the human body and subsequently excreted, andby breakdown products of the parent compounds by microbes in the aquatic and soilenvironments. The U.S. Congress passed the Food Quality Protection Act and the Safe DrinkingWater Act Amendments of 1996, which require the U.S. Environmental Protection Agency(EPA) to screen pesticides for estrogenic effects on human health and permits EPA to screenchemicals found in drinking water sources for hormonal effects.

The primary goal of the project is to develop analytical methods to support relevant and topicalresearch on the fate and transport of the target EDCs in sewage treatment plants. The followingconstraints were considered when designing the initial method development approach containedin this document:

a) The methods should be cost-effective.

b) The methods can be performed in house.

c) The methods should be well documented for future users.

d) The methods should be based on successful techniques reported in the literature.

e) The methods should use widely available instrumentation that does not requirecomplex and difficult modifications.

f) The methods can be adapted (expanded target lists and/or matrices) for futureresearch studies.

6. Development of a Protocol for Field-Testing the Effectiveness of Oil Spill RemediationTechnologies for Spills of Opportunity

Numerous oil spills occur every year and there is a great need to have a decision framework fordetermining the best response tool to treat them. The main objective of this project is to developa protocol enabling an investigator to determine the effectiveness of a given treatmenttechnology at a spill site with a high degree of certainty. An integral part of this protocoldevelopment is the use of modern spatial statistical techniques to develop a protocol for fieldtesting oil spill remediation processes in a spill of opportunity or real spill scenario. The idea isto be able to estimate the density of a grid network needed to illustrate the overall effect ofremedial treatment being imposed on the site for cleanup purposes. This will aid the responderin determining the minimum number of samples to collect to determine effectiveness oftreatment. The response surface will automatically account for hot spots and cold spots and willenable the investigator to monitor progress through time over the entire treated area withoutresorting to the necessity to calculate plot means, which could significantly overestimate orunderestimate effectiveness of treatment. This type of information could be extremely useful forother environmental sites besides oil spill sites.

7. Develop Dispersant Effectiveness Data for a Suite of Environmental Conditions

US EPA is developing a simulation model called the EPA Research Object-Oriented OilSpill (ERO³S) model which is intended to assess the impacts of dispersant usage on oil spills. ERO³S is based upon an object-oriented software design that implements an oil spill model thatuses classical spreading models, transient lagrangian transport, and multicomponent massbalance concepts. As such the model is based upon first principles for simulating a portion of theoil slick behavior. Because of the complexity, however, of the chemical and physicalinteractions between spilled oils and the sea, a portion of the behavior of the spill oil must bebased upon empirical data. Empirical relationships are used, for example, to drive volatilizationof individual chemicals from the oil and the formation of emulsions. Other inputs for the modelare derived from associated completed and on-going research projects. These include use of theEPA/University of Georgia SPARC on-line calculator for estimation of chemical properties(solubilities and henry's constants at various temperatures), compilation of oil composition data,compilation of environmental data from NOAA buoys, and the development of methods toaccount for wave and tidal impacts.

For the purposes of ERO³S, the impacts of dispersants on oil slicks are best characterized byempirical data, because 1) the dispersants in use are proprietary formulations, 2) the chemicalinteractions between surfactants and components of the oil are complex, and 3) the physicaleffects on the oil are similarly complex. Modeling dispersant and oil interactions using firstprinciples approaches, although interesting from a pure research perspective, is not plannedbecause of intended use of the model as an emergency-response decision-making tool, theuncertainties in numerous other required inputs to the model and the computational intensivenessof detailed modeling approaches.

Thus the intent of this project is that the University of Cincinnati (UC) will create a set ofempirical data on three oils and two dispersants that has the potential of use as input to ERO³S. Depending on the nature of the results the data may be used to determine the amount of oil that isdispersed at a given time in a spill scenario. EPA has recently developed an improved dispersanttesting protocol, called the baffled flask test (BFT). This test had the promise of being able toovercome limitations of previous test methodologies which included non-reproducibility andnon-representativeness of field conditions. In this project, UC will explore the variation in theeffectiveness of dispersants caused by changes in temperature, oil composition, oil weathering,dispersant type, and rotation speed of the BFT. Oils have an inherent tendency for "natural"dispersal because of the composition of the oil and the amount of energy imparted by the sea. Thus, a set of control experiments will be conducted for accounting for the natural dispersal ofthe oils. All of the information and data generated by UC for this project will be evaluated byEPA and if the results are suitable, they will be used in ERO³S simulations of dispersant usage.

8. Assessment of Effects of Risk Management Activities on the Speciation and Transport of Mercury in Aquatic Sediments

The objective of this project is to provide a better understanding on the behavior of mercury during and after the implementation of a risk management option. The project will attempt to predict the distribution of inorganic and organometallic mercury species in the sediment water based on (i) mercury concentration and speciation data prior to the remediation activity, (ii) physicochemical, biological, and hydro-geological data and analysis of the water/sediment system, and (iii) type, extent and purpose of the remedial action. The study will consider three individual scenarios (and if necessary combinations between them) of mercury contamination: (1) urban, (2) industrial, and (3) mining. For each scenario, the effects of three remedies will be evaluated: (1) dredging (spoils and remaining sediment), (2) in-situ capping, and (3) natural attenuation. Since each remedy can result in a change in the physical, chemical, and biological conditions of the sediment, it is expected that the speciation and transport of mercury will change as the result of implementing a remedy. The project will rely on both literature and existing models to provide information on the fate of mercury during and after the implementation of each of the three proposed remedies. The analysis will provide a critical literature review considering the extent of mercury contamination, mercury speciation, water and sediment physicochemical characteristics, level of microbial activity, geological and hydrological characteristics of the contaminated site and extent of sediment disturbance during the remediation process. To achieve this however, a clear understanding on the physicochemical interactions of mercury in water, sediments, soil, and atmosphere is required. Existing models and advanced modeling software will be used to study these interactions. If necessary, existing models will be modified or more rigorous models will be developed. The study will be critical and will attempt to address inconsistencies in previous published literature.

9. Development of Novel Combined Treatment Technologies for Decontaminating Polluted Air

This project focuses on development of a combined treatment scheme (PSA/TBAB) that is adaptable to any particular contaminant or mixture of contaminants. A pressure swing adsorption (PSA) unit followed by a trickle bed air biofilter (TBAB) unit is proposed for yielding an effluent stream complying with emission regulations during adverse conditions of industrial operations. The objectives of this research study are: 1) to study the influence of fluctuating contaminant concentration, periods of non-use, and change of contaminant on the performance of the TBAB; 2) to investigate the mechanism of single solute and competitive equilibrium adsorption on different types of adsorbents for the contaminants of concern; and 3) to investigate the operating pressurization, and de-pressurization cycles for the PSA unit that will yield constant loading conditions on the biofilter and will provide contaminant removal above 99 %. The development of a combined PSA/TBAB technology will be of significant benefit to the chemical industry where off-gas treatment is necessary for complying with the Clean Air Act. It is anticipated that effluent treatment cost will be significantly reduced by enhancing the performance of the biofiltration process. The combined treatment technology of this research provides excellent case studies for both the undergraduate and graduate classes. Research experience gained in the laboratory will be replicated in the classroom by developing discovery-based teaching modules, so the experience can be shared by all of the students. Problem-based learning, undergraduate research and research-based education will help students develop critical thinking, problem solving, teamwork and communication skills.

10. A Comparative Study for Treatment of Source Water Contaminants Using Advanced Oxidation Process

Methyl tertiary butyl ether (MTBE), trichloroethylene (TCE) and perchlorate (ClO4) are contaminants commonly found in ground and surface water. Advanced oxidation processes (AOPs) provide a promising treatment option for most organic compounds. AOPs destroy organic pollutants directly in water through chemical transformation, as opposed to simply transferring them from the liquid phase to the gas phase (in the case of air stripping) or solid phase (in the case of adsorption). UV lights commonly used in water treatment include; continuous wave low-, medium-, and high-pressure mercury vapor lamps and pulsed-UV xenon arc lamps. Low pressure lamps are primarily monochromatic with effective ozone producing (185 nm) and germicidal (254 nm) wavelengths. Medium pressure lamps are typically polychromatic with effective germicidal wavelengths of 254 nm and 365 nm. Ultraviolet light (UV), in conjunction with an oxidizer such as hydrogen peroxide (H2O2), titanium dioxide (TiO2), or ozone (O3), produce hydroxyl radicals (•OH) that attack and degrade organic compounds. Photofenton reactions combine UV, hydrogen peroxide and iron to produce hydroxyl radicals. The proposed study will investigate the degradation of MTBE in dechlorinated tap water using pilot-scale AOP technologies (KMnO4, O3/H2O2, UV/H2O2, Photofenton, UV/TiO2, UV/O3, and Pulsed UV). The study will include a technical and economic feasibility analysis of treatment technologies. Thus the primary objective of this AOP study is to evaluate the destruction of MTBE using AOP pilot-scale treatment technologies (KMnO4, O3/H2O2, UV/H2O2, Photofenton, UV/TiO2, UV/O3, and Pulsed UV). The specific objectives are: evaluate the impact of various operational (i.e., UV intensity, oxidant concentration) and water quality parameters (i.e., alkalinity, NOM), determine the reduction kinetics of MTBE degradation, identify the oxidation byproducts and propose a reaction mechanism, examine the kinetics of the formation and subsequent destruction of byproducts, and provide a comparative analysis of the operational efficiencies and economics of AOP technologies.

11. Biodegradation Patterns and Toxicity of the Constituents of Canola Oil and its Intermediate Breakdown Products

Edible oils and fats are primarily composed of triglycerides. Individual fatty acids (FAs) are distinguished from one another by the nature of the hydrocarbon chain. This chain can vary in length from 4 to 24 carbon atoms and can be saturated, monounsaturated, or polyunsaturated. The most common FAs in edible oils and fats are those containing 18 carbon atoms. These include stearic acid (fully saturated), oleic acid (monounsaturated), and linoleic and linolenic acids (containing 2 and 3 double bonds, respectively). These FAs are abbreviated according to the number of carbon atoms in the molecule and the degree of unsaturation. Although the carbon atoms are generally counted from the carboxyl end of the FA, for biological activity they are also numbered from the methyl end. Such a classification is designated by the symbol w (Greek letter omega), which denotes the position of the double bond closest to the methyl group. For example, linoleic acid with 2 double bonds has 1 located 6 carbon atoms from the methyl group. This FA is thus abbreviated C18:2w6. The objectives of this three years task order are to design and conduct experiments on four triglycerides of 16:0, 18:1, 18:2, and 18:3 FA to delineate the cause of the induced toxicity (as determined by Microtox assays), and to investigate the contribution towards toxicity of the various triglycerides of vegetable oils. The experiments are designed to determine the rate and extent of the triglycerides biodegradation in a respirometry flask test, to monitor changes in toxicity in the water column during biodegradation, and to identify the cause(s) of the observed increased toxicity and to generalize the results for four refined vegetable oils (Canola, Sunflower, Olive, and Palm oils).

12. Adsorption of Phenolics on Activated Carbon Fibers

Activated carbon has been used in many ways for the removal of organic pollutants in water and wastewater treatment. Adsorbent pore size distribution (PSD) is one of the most important properties that influence the adsorption process. Compared with granular activated carbon (GAC), activated carbon fiber (ACF) has a unique pore size distribution, suitable to be used to elucidate the effect of pore structure on adsorption. Adsorbate property is another factor that influences adsorption. Phenolic compounds undergo oglimerization on the activated carbon surface when oxygen is present in the test environment and appreciable increases in the adsorptive capacity has been documented at the cost of lower regeneration of activated carbon after being exhausted by the contaminants. Regeneration efficiency of activated carbon has been a major concern in activated carbon usage. Thus the primary objective of this study is to determine the adsorption behavior of phenolic compounds with different functional groups on activated carbon fibers as compared to granular activated carbon. The specific objectives are: to conduct single solute adsorption isotherms for phenolic compounds on four different activated carbon fibers with different pore size and on a commonly used granular actived carbon (F400), to conduct binary adsorption isotherms of selected phenolic compounds on selected activated carbon fibers based on the results obtained from the single solute system, to conduct ternary adsorption isotherms of selected phenolic compounds on selected activated carbon fibers based on the results obtained from the binary system, and finally to determine the attachment of phenolic compounds on the different adsorbents studied.