A process for the purification of organochlorine contaminated activated carbon : sequential 1 solvent purging and

10 A system for the purification of organochlorine contaminated activated carbon is described. The 11 system involves a continuous flow of aqueous ethanol to purge organochlorines from activated 12 carbon. The organochlorine laden solvent is simultaneously treated with zero valent zinc as the 13 bulk electron source, water as the proton source and the electron shuttle cyanocobalamin as a 14 catalyst for reductive dechlorination. The system was characterised by performing batch 15 reactions and extractions before being applied in a continuous flow system. In particular the 16 ratio of water to ethanol in the system needed to be optimised. Water is needed for the reductive 17 dechlorination reaction whilst it is not conducive to the extraction process. An 80% ethanolic 18 solution was found to give optimal reductive dechlorination rates without compromising 19 extraction of organochlorines from activated carbon. Of three electron shuttles evaluated 20 cyanocobalamin was discovered to be the most relevant to the system with respect to reductive 21 dechlorination rates and its ability to avoid absorption to activated carbon. 22