Abstract:
To study remediation of organochlorine pesticides (OCPs) contaminating soils with root exudates, alfalfa, which is common in Yan’an, was used as experimental material, and the method of simulated restoration experiment was used. The results showed that: ① Root exudates could significantly increase the removal rate of OCPs in soil, and the removal rate reached the highest when the amount of root exudates increasing from 30mL to 40mL (about 100 g of contaminated soil sample per bottle), in the range of experimental concentration; ② The average contribution rate of root exudates to OCPs removal was 36.43%, which was significantly higher than that of abiotic factors and soil original microorganisms. ③ The addition of root exudates could increase the number of microbes in soil, and there was a significant linear positive correlation between the addition of root exudates and the amount of microbes in soil at a certain pollution concentration; ④ Root exudates changed the structure of microbial communities by changing the amount of the components in microbial communities, especially fungi and bacteria affected by root exudates. ⑤ There was a positive parabola relationship between the concentration of OCPs removal and the amount of root exudates. Therefore, root exudates could enhance the repairing effect of OCPs by changing the number of microbes in soil and their community structure.