title: EPR characterization of the catalytic activity of clays for PCE removal by gamma-radiation induced by acid and thermal treatments.
abstract: Clays from tidal flat sediments showed efficient catalytic activity in the decomposition of PCE by gamma-radiation. The highest PCE removal of 98.6% was obtained with clays heated to 700 degrees C after acid treatment. The improved catalytic activity was identified by electron paramagnetic resonance (EPR) spectroscopy. The EPR spectra of clays were significantly changed by the acid and thermal treatments. The intensity of a narrow signal at g=2 (signal III) was decreased with increasing thermal treatment temperature and this increased the PCE removal efficiency. The acid treatment completely removed a broad signal at g=2 (signal II), decreased the intensity of signal III, and improved the gamma-radiation treatment of PCE.
authors.affiliation: Department of Industrial Chemistry, College of Engineering, Yosu National University, Yosu 550-749, South Korea.
authors.forename: Hung-Ho
authors.initials: HH
authors.lastname: Chung
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Choi
authors.forename: Yong-Sik
authors.initials: YS
authors.lastname: Ok
authors.forename: Jinho
authors.initials: J
authors.lastname: Jung
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D002384:Catalysis; D004578:Electron Spin Resonance Spectroscopy; D004787:Environmental Pollution / Q000517:prevention & control; D005720:Gamma Rays; D019015:Geologic Sediments / Q000032:analysis*; D006358:Hot Temperature; D006851:Hydrochloric Acid; D007723:Korea; D013750:Tetrachloroethylene / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D006851:Hydrochloric Acid; D013750:Tetrachloroethylene