Remediating Chlorpyrifos-ContaminatedSoil Using Immobilized MicroorganismTechnology

Chlorpyrifos, one of the common broad-spectrum insecticides, can damage the human nerve system - even to the point of death under long-term exposure. In addition, chlorpyrifos is hard to be naturally degraded because of its strong combination with soil particles and long half-life. So repairing the polluted soil is urgently needed. In this study, the embedding and crosslinking immobilization techniques were used to determine the degradation of chlorpyrifos in soil. After 16SrDNA analysis, the results showed that LLBD2 is Bacillus cereus and LLBD4 is bacillus sp., and bacteria immobilized on the degradation of chlorpyrifos were significantly better than the free bacteria. The degradation rate reached 83.28% after LLBD2 being immobilized within 72 h. Furthermore, the environmental factors influenced with LLBD2 showed that immobilized bacteria were more adapted to the changed environment than the free one. Although the initial concentration, pH, and temperature were significantly changed, the degradation rate of chlorpyrifos by immobilized bacteria was stable, suggesting that environmental factors had little influence on the immobilized bacteria.