show Abstracthide AbstractAt a former industrial site in Nanjing China, a long time site investigation and corresponding lab microcosms study were conducted. Results revealed that the main contaminants were chlorobenzenes and benzene. Chlorobenzenes undergo substantial dechlorination to less chlorinated benzene and finally benzene is accumulated. However, benzene is a carcinogenic mono-aromatic hydrocarbon that is a problematic contaminants in groundwater and soil. Oxygen is usually limited in aquifer, making anaerobic benzene degradation essential. In this study, chlorobenzenes and benzene degrading enrichment culture were obtained.