Oxidative-Reductive Methods for Remediation Remediation of Chlorinated Groundwater Contaminants via Reductive Dechlorination Metallic iron may serve as a reductant for the dehalogenation of chlorinated contaminants in aqueous systems. For many contaminants, such as TCE, the available iron surface area limits the rate of transformation, and extended contact periods on the order of days are required to achieve practical levels of transformation. By employing high specific surface area iron-impregnated silica gels, and palladized iron in column reactors, the rates of transformation can be increased. Although ozone is one of the most powerful oxidants available for water treatment, the degree of organic oxidation, stoichiometric and kinetic responses are unacceptably low in some instances. Manipulation of reactor conditions through the addition of catalysts such as ultraviolet light and ultrasound, enhances the production of free radicals and extends the oxidation capability of ozone.
Research focuses on the use of advanced oxidation processes.
Subsurface Remediation Using Air Sparging The injection of air directly into contaminated aquifers, termed air sparging, can accelerate the rate of aquifer remediation. In laboratory column experiments, we are determining mass transfer coefficients for air sparging by measuring the effects of sparging on remediation times of NAPLs in contaminated porous media. Membrane Processes Filtration processes employing microfiltration, ultrafiltration, nanofiltration and reverse osmosis are subject to fouling with concomitant loss of productivity and permeate quality. Therefore, proper pretreatment of membrane process influent is essential. Reduction in fouling potential by particle electric charge manipulation, partial oxidation of polymeric materials of both natural and manmade origin, and use of various filtration devices will provide the required level of pretreatment.