About Open Access
Sorption of dichlorodiphenyltrichloroethane (DDT) and its metabolites by activated carbon in clean water and sediment slurries
Lookup NU author(s)
Professor Richard Luthy
Dr David Werner
Hale SE, Tomaszewski JE, Luthy RG, Werner D
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Polyethylene-water partitioning coefficients (KPE) and mass transfer coefficients (kPE) for the ortho and para isomers of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) and its metabolites dichlorodiphenyldichloroethane (DDD), dichlorodiphenyldichloroethylene (DDE) and, dichlorodiphenylmonochloroethylene (DDMU) were measured. These data were used to derive activated carbon (AC) sorption isotherms in clean water in the sub-nanogram per litre free aqueous concentration range for a virgin and a regenerated AC. The sorption strength of AC for DDT and its metabolites was very high and logarithmic values of the AC-water partitioning coefficients, log KAC, ranged from 8.47 to 9.26. A numerical mass transfer model was calibrated with this data to interpret previously reported reductions in DDT uptake by semipermeable membrane devices after AC amendment of sediment from Lauritzen Channel, California, USA. The activated carbon-water partitioning coefficient values (KAC) measured in clean water systems appear to overestimate the AC sorption capacity in sediment up to a factor 32 for DDT and its metabolites at long contact time with fine-sized AC. Modelling results show decreased attenuation of the AC sorption capacity with increased sediment-AC contact time. We infer that increased resistance in mass transfer of DDTs to sorption sites in the microporous region likely caused by deposits of dissolved organic matter in the macro- and mesopores of AC appears to be the most relevant fouling mechanism. These results suggest that DDTs may diffuse through possible deposits of dissolved organic matter over time, implying that the effects of sediment on the sorption of DDTs by AC may be more kinetic than competitive.
Newcastle University Library, NE2 4HQ, United Kingdom. Tel: 0044 (191) 222 7657
©2015 Newcastle University Library