title: Degradation of pentachlorophenol in contaminated soil suspensions by potassium monopersulfate catalyzed oxidation by a supramolecular complex between tetra(p-sulfophenyl)porphineiron(III) and hydroxypropyl-beta-cyclodextrin.
abstract: To enhance the catalytic oxidation of pentachlorophenol (PCP) in contaminated soil suspensions using tetra(p-sulfophenyl)porphineiron(III) (Fe(III)-TPPS) as a catalyst and potassium monopersulfate (KHSO(5)) as the single-oxygen donor, the effect of added hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was examined. At pH 4 and 6, the percentage of PCP disappearance increased substantially in the presence of HP-beta-CD. In addition, the self-degradation of Fe(III)-TPPS was significantly retarded in the presence of HP-beta-CD. This retarded self-degradation can be attributed to the stabilization of Fe(III)-TPPS via the formation of a supramolecular complex with HP-beta-CD. The kinetic constant for the self-degradation of Fe(III)-TPPS in the presence of HP-beta-CD at pH 6 was much smaller than that at pH 4, indicating that Fe(III)-TPPS is more stable at pH 6. Thus, the amount of Fe(III)-TPPS, KHSO(5) and HP-beta-CD required to degrade PCP in contaminated soil suspensions was optimal at pH 6. When PCP-contaminated soil suspensions were treated under the optimized conditions, 12-18% and 24-28% of the PCP was mineralized to CO(2) in the absence and presence of HP-beta-CD, respectively. These results show that the presence of HP-beta-CD in the Fe(III)-TPPS/KHSO(5) catalytic system is effective in enhancing the degradation of PCP in contaminated soil suspensions.
authors.affiliation: Division of Solid Waste, Resources and Geoenvironmental Engineering, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan. m-fukush@eng.hokudai.ac.jp
authors.forename: Masami
authors.initials: M
authors.lastname: Fukushima
authors.forename: Kenji
authors.initials: K
authors.lastname: Tatsumi
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D002384:Catalysis; D052918:Environmental Restoration and Remediation / Q000379:methods; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010416:Pentachlorophenol / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D011166:Porphyrins; D017680:Potassium Compounds; D012989:Soil Pollutants; D013431:Sulfates; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; C016136:tetraphenylporphine sulfonate; C009007:potassium persulfate; D010416:Pentachlorophenol