In our study,the BHC could be degraded in the sewage sludge of wastew-ater reservoir. The microorganisms played a very important part in degradation.The rate of BHC degradation under anaerobic conditions was more rapid than at 25-30℃. After 20 days beginning the experiment approximately 90% BHC were degraded. γ-BHC can be decomposed by above 30 strains of bacteria which were anaerobically isolated from the sewage sludge. A γ-BHC decomposer was identified to be Bacillus brevis.A small amount of γ-BHC and a d...