Decomposition of 2,2',4,4',5,5'-hexachlorobiphenyl with iron supported on an activated carbon from an ion-exchange resin.

An activated carbon (AC) containing a high concentration (374mgg(-1)) of Fe was prepared by carbonization of an ion-exchange resin. To examine its chemical reactivity as a catalyst to decompose 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153), the decomposition parameters of temperature and time were varied under air or N(2). Decomposition at 350°C was achieved within 15min under air and 30min under N(2), and the efficiency of PCB-153 decomposition was 99.7% and 98.0%, respectively. An analysis of inorganic chloride ions revealed that PCB-153 was mineralized effectively during the decomposition. The Brunauer-Emmett-Teller (BET) surface area and pore volume of the AC were measured to assess the adsorption capacity before and after the decomposition. The differences between decomposition under air and N(2) reflected the differences in the BET surface and pore volume measurements. A decomposition pathway was postulated, and the reactive characteristics of chlorine atoms loaded on the benzene rings followed the order of para>meta>ortho, which agrees with the calculated results from a density functional theory study.