Anaerobic and aerobic sequential process, a promising strategy for breaking the stagnate of biological reductive dechlorination

Trichloroethylene (TCE) is a common chlorinated hydrocarbon contaminant in soil and groundwater, and reductive dechlorination is a biological remediation. However, the TCE reductive dechlorination often stagnates in the stage of cis-1,2-dichloroethylene (cDCE) and chloroethylene (VC). Anaerobic/aerobic sequential degradation provides a new approach for the complete detoxification of TCE, while there has been no systematic summary of bacteria, enzymes, and pathways in the synergistic process. Herein, the objectives of this review are (1) to discuss the reasons why it is difficult to completely reduce dechlorination; (2) to analyze the advantages and pathways of TCE complete detoxification through anaerobic/aerobic sequential degradation process; (3) to summarize the major bacteria and catalytic enzymes of the cDCE and VC oxidation process. This review will highlight the anaerobic/aerobic process in TCE biodegradation and increase understanding of the complete detoxification of chlorinated hydrocarbons.