Effect of composting on volatilization and degradation of organo-chlorine pesticide

Aerobic composting treatments using chicken manure and corn straw as the composting material at high temperature were performed in order to study the effect of composting on the volatilization and degradation of HCH and DDT. The study show that 20.6% of HCH and 13.8% of DDT volatilized due to high temperature and ventilation during the period of composting, which accelerated the volatilization of HCH and DDT to gas phase within 30 days. Apart from the effect of high temperature and ventilation on the volatilization of organochlorine pesticides, the degradation rates of HCH and DDT in the treatment without microbial inoculums were 37.2% and 14.9%, respectively. The degradation rates of HCH and DDT in the treatment with microbial inoculums were 42.1% and 24.2%, respectively. The significant difference between the treatment without microbial inoculums and the one with microbial inoculums was found. The degradation rates of α-HCH and δ-HCH were higher than those of β-HCH and γ-HCH. The degradation rates of pp'-DDT and op'-DDT were higher than those of pp'-DDD and pp'-DDE. The results indicate that high temperature and ventilation accelerated the volatilization of HCH and DDT to the gas phase during the composting and the biochemical reactions in this process contributed to the degradation of organochlorine pesticides such as HCH and DDT.