Effective and Safe Composting of Chlorophenol-Contaminated Soil in Pilot Scale

A pilot-scale composting of chlorophenol-contaminated soil was performed to compare chlorophenol degradation by two different inoculants, straw compost and remediated soil, with that by indigenous soil microbes. Four compost piles with a size of 13 m3 each were constructed. Chlorophenol and chloroanisole concentrations as well as numerous physical and microbiological parameters were monitored during 6 months of composting. Over 90% of the chlorophenols were removed during the composting period. The biodegradation of chlorophenols was efficient and fast despite the inocula. Frequent mixing and control of the nutrient level enhanced the chlorophenol degradation activity of the indigenous microbes in the contaminated soil. In a parallel bench-scale experiment, an average of 60% mineralization of radiolabeled pentachlorophenol ([14C]PCP) was obtained in 4 weeks in 1-kg piles with or without inocula. This result showed that a major part of chlorophenols was completely mineralized.