Research

The group's research focuses on developing sustainable technologies for water treatment, point-of-use devices, and water reuse applications.  The research is often interdisciplinary and thus collaboration with Engineers, Chemists, Biochemists, Material Scientists, Geologists, and Microbiologist is necessary.  Current areas of research include:

Catalytic and Electrochemical Treatment for Water Reuse— With the increasing ability of analytical techniques to detect contaminants at the sub-ppb level, more and more pollutants are being observed in our water supply (e.g., disinfection byproducts, pharmaceuticals, and endocrine disruptors). As toxicity studies on these contaminants are performed, it is evident that remediation strategies for these emerging contaminants must be developed. Since many areas are relying on the reuse of wastewater for irrigation or direct groundwater recharge, the need to assure that persistent contaminants do not remain in the water supply is even more important. Research is underway using catalytic and electrode mediated treatment in combination with sorbents and membranes to treat these trace contaminants. Sorbents and membranes are used to concentrate these contaminants, thus making catalytic and electrode mediated treatment more efficient and cost effective.  Research is focused on the following areas: 1) development and characterization of novel catalysts and electrode materials for contaminant degradation, 2) understanding of the molecular-scale mechanisms of the chemical transformation of these compounds through in situ experiments and computational methods, and 3) using the information gained from these in situ experiments to optimize the material properties and operating conditions of these processes. 

Electrochemical Disinfection— Bacterial contamination of drinking water is an enormous problem worldwide, and is the leading cause of death among children in developing countries.  Contaminantion can occur in the water source or within the distribution system.  There thus is a need for the development of point-of-use devices for water disinfection to protect against pathogens in water.  Research is currently underway on the development of point-of-use disinfection units.  Conductive ceramic membranes are being explored as the key component of these point-of-use devices.  The membrane is utilized as both a physical barrier and destructive method to destroy bacteria.  Research is currently focused on optimizing the material properties (e.g., surface charge, surface functionality, and pore size) of the membranes to achieve efficient water disinfection.  Careful monitoring of the water chemistry is also being conducted to assure that disinfection byproduct formation is not occuring. 

Boron-doped Diamond Electrode Development— Work is curently underway with Advanced Diamond Technologies, a manufacturer of diamond electrodes, to develop boron-doped ultrananocrystalline diamond (UNCD) electrodes for the destruction of recalcitrant organics in industrial wastewater via direct anodic oxidation.  Boron-doped diamond (BDD) film electrodes have generated considerable interest due to their ability to readily mineralize complex waste streams. Other treatment methods (e.g., reverse osmosis and activated carbon), simply concentrate toxins thus producing residuals requiring disposal in hazardous landfills or incinerators. UNCD technology provides many advantages over traditional diamond electrodes (e.g. thin low-stress phase-pure films) that are expected to improve the cost/lifetime of UNCD electrodes and enable electrochemical wastewater treatment technologies. UNCD films consist of phase pure, 2-5nm grains with atomically abrupt grain boundaries. UNCD costs less than larger-grained BDD films because they are formed in much thinner/uniform pin-hole free layers.  The objective of this work is to optimize the existing boron-doped UNCD technology to develop low-cost, long-lifetime electrodes to enable wide-spread adoption of electrochemical wastewater treatment technologies. The project will determine the effect of surface morphology, doping, substrate and processing methodology for UNCD electrodes to quantify costs, electrochemical performance and lifetime for wastewater treatment/destruction.  The performance of electrodes is currently being evaluated by peforming oxidation experiments with perfluorinated and chlorinated organics (i.e., PFOS and TCE).