Remediation of DDT contaminated soil by using laccase in different application ways

Effect of different application ways (application dose, batch application and unsterilized soil) of laccase on remediation of DDT in soil was investigated. The results show that degradation rate of DDT in soil increased significantly with increasing application dose of laccase except P,P’-DDE. The degradation rate of DDTs was up to 50.63% when adding dose of laccase was 6U per gram soil. Degradation rate of DDT in soil treated with two times addition of laccase is 11.4% higher for DDTs than that treated with one time addition of laccase with the equivalent dose of laccase. Degradation rates of DDT in unsterilized and sterilized soils both treated by laccase are equivalent for total DDT(DDTs), but significantly different for individual compounds, with degradation rates of P,P’-DDE,O,P’-DDT, and P,P’-DDD in unsterilized soil is significantly lower than those of which in sterilized soil and conversely for P,P’-DDT.