Surfactants Strengthen Cole-Microorganism for the Remediation of DDTs Contaminated Farmland Soils

In order to improve the remedial effects of DDTs contaminated soils in facility agriculture,a field experiment was conducted to enhance different concentrations of SDBS-TW80 and RL for bioremediation of DDTs contaminated soils by combining with cole and Bacillus methylotrophicus. The results show that the degradation rate of DDTs in soils by cole, degrading and cole-microorganism bacteria after one month were 12.0%, 38.2% and 43.1%, respectively, which was significantly higher than that in control treatment. SDBS-TW80 and RL could enhance the degradation rate of DDTs contaminated farmland soils by Bacillus methylotrophicus and cole. The highest degration rates of DDTs in farmland soils were 56.5% and 65.7%, respectively, when the concentration of SDBS-TW80 and RL was applied at 40 and 5 mg·kg^-1, respectively. RL showed higher degradation activity of DDTs than SDBS-TW80. Moreover, highest degradation rate of p,p'-DDE (the most toxic component) was about 69.5%, when the concentration of RL was applied at 5 mg·kg^-1. The results confirmed the workability of surfactants augmented remediation of DDT-contaminated soil by cole and Bacillus methylotrophicus. Considering the remediation efficiency and toxicity, RL was the best choice in practical application.