title: Degradation of volatile organic compounds with thermally activated persulfate oxidation.
abstract: This study investigated the extent and treatability of the degradation of 59 volatile organic compounds (VOCs) listed in the EPA SW-846 Method 8260B with thermally activated persulfate oxidation. Data on the degradation of the 59 VOCs (in mixture) reacted with sodium persulfate in concentrations of 1 g l(-1) and 5 g l(-1) and at temperatures of 20 degrees C, 30 degrees C, and 40 degrees C were obtained. The results indicate that persulfate oxidation mechanisms are effective in degrading many VOCs including chlorinated ethenes (CEs), BTEXs and trichloroethanes that are frequently detected in the subsurface at contaminated sites. Most of the targeted VOCs were rapidly degraded under the experimental conditions while some showed persistence to the persulfate oxidation. Compounds with "CC" bonds or with benzene rings bonded to reactive functional groups were readily degraded. Saturated hydrocarbons and halogenated alkanes were much more stable and difficult to degrade. For those highly persulfate-degradable VOCs, degradation was well fitted with a pseudo first-order decay model. Activation energies of reactions of CEs and BTEXs with persulfate were determined. The degradation rates increased with increasing reaction temperature and oxidant concentration. Nevertheless, to achieve complete degradation of persulfate-degradable compounds, the systems required sufficient amounts of persulfate to sustain the degradation reaction.
authors.affiliation: Environmental Research Institute, University of Connecticut, 270 Middle Turnpike, U-5210, Storrs, CT 06269-3210, USA. khuang@eri.uconn.edu
authors.forename: Kun-Chang
authors.initials: KC
authors.lastname: Huang
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhao
authors.forename: George E
authors.initials: GE
authors.lastname: Hoag
authors.forename: Amine
authors.initials: A
authors.lastname: Dahmani
authors.forename: Philip A
authors.initials: PA
authors.lastname: Block
mesh_terms: D009930:Organic Chemicals / Q000737:chemistry*; D010084:Oxidation-Reduction; D017670:Sodium Compounds / Q000737:chemistry*; D012989:Soil Pollutants; D013431:Sulfates / Q000737:chemistry*; D013696:Temperature; D014835:Volatilization; D014874:Water Pollutants, Chemical; D018508:Water Purification
chemical_list: D009930:Organic Chemicals; D017670:Sodium Compounds; D012989:Soil Pollutants; D013431:Sulfates; D014874:Water Pollutants, Chemical; C024625:sodium persulfate