This program concentrates on the development of methods to evaluate risks from a hazardous waste disposal site, and is assessing the feasibility of mitigating such risks using either native soil micro-organisms or bacteria with specific biodegradative traits. The principle hypothesis for this approach is that a waste site is a dynamic system which presents evolving risks. Changes in risk to organisms located near a waste site are a function of various interrelated actions including the movement of toxic chemicals within and off the site, the chemically and microbiologically catalyzed transformations of waste materials, and the toxicant interactions which are based on exposures to multiple chemicals. This program aims to understand these changes in order to design remediation strategies for the most hazardous materials located at a particular site.
Substances chosen for study include chlorinated hydrocarbons and toxic metals.
Six projects center on bioremediation technologies with research involving collaborative efforts from the disciplines of engineering, microbiology, and soil sciences. One project focuses on biodegradation within metal and organic contaminated soils, and will use the biomarker assays developed in the project to document changes in the soil microflora following additions of contaminants to soil in field scale lysimeters. A comparative project is examining biosurfactant enhanced in-situ remediation of soils contaminated with metals. In another project, the influence of coupled physical chemical processes on bioremediation and biodegradation of organic compounds is being evaluated. One project investigates bacterial transport in saturated, unsaturated, and air-sparged porous media.