Aliphatic organochlorine degradation in subsurface environments

Organochlorines are simultaneously of great value to society and a great threat to human health and the living environment. Their recalcitrance, toxicity and carcinogenicity have driven research activity towards an understanding of degradation mechanisms in the environment and the development of technologies enhancing degradation. This review focuses primarily on the role of organochlorine respiring bacteria in the dechlorination of chlorinated ethenes, ethanes and methanes in subsurface environments. Attention is given to the biogeochemical setting of organochlorine reduction with the influences of co-habiting microbial communities and iron and sulphur cycling considered. This is done in relation to existing technologies to enhance subsurface reductive dechlorination including reactive iron barriers and nano-scale zero valent iron. Overall, a remarkable body of knowledge has been generated in this sphere over the past two decades, giving hope that the global community can continue making use of organochlorines without further impacting on human and environmental health.