Development of a Two Stage Bioremediation Technology for Dioxin Contaminated Soils

The compound 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD) has been called the most toxic compound known to man. 2,3,7,8-TCDD is globally distributed but is found in high concentration at many hazardous waste sites associated with the production and use of chlorinated pesticides/herbicides. Traditionally, contaminated soils have been excavated and transported off site to a hazardous waste incinerator. This process has significant economic and public relations disadvantages. It is proposed in this study that a two stage proprietary slurry phase treatment strategy be developed for the treatment of dioxin contaminated soils to provide a lower cost treatment technology that is potentially implementable on-site. The first stage of this process would use a chemical agent to make the compounds more amenable to biological treatment. This would be followed by a biological process to complete the degradation process. The combined process would either completely mineralize or largely detoxify the components of interest. The partial success achieved by other investigators using chemical processes to treat dioxins in soil and in biological processes to degrade suggest that the proposed process which couples these two technologies has a good possibility of success.