Treatment of Dioxin-Contaminated Soil by Organic Waste Co-composting System

Food waste collected from kitchen leftovers and dinner tables were applied to co-composting dioxin-contaminated soils. The initial TEQ of the soil was 6048 ng-TEQ/kg dry wt, which was 6 times higher than the limit standard of 1000 ng-TEQ/kg dry wt issued by Taiwan EPA. It then decreased quickly by around 50% to 2934 ng-TEQ/kg dry wt at the 7 days. Though about 70% of PCDD/Fs had successfully degraded with co-composting approach after 49 days, the final TEQ value of 1604 ng-TEQ/kg dry wt remained higher than the standard limit of dioxins in soil (1000 ng-TEQ/kg dry wt). Subsequent attempts to bring the final TEQ value down to the standard limit are required. Nevertheless, this study has successfully demonstrated an enhanced thermophilic biodegradation approach to degrade dioxins. And the operation of the biological treatment is believed more robust and easier to operate in comparing to other traditional approaches while dealing with mesophiles.