title: Transformation of polychlorinated biphenyls by persulfate at ambient temperature.
abstract: Increasing attention has been paid to persulfate due to its high efficiency in degrading organic pollutants. This paper investigated the transformation of a selected polychlorinated biphenyl (PCB) by sodium persulfate without activators at near ambient temperature (10-40°C). The results showed that 2,4,4'-CB was completely decomposed by persulfate at 30°C in 8 h. The products were identified by gas chromatography-mass spectrometry (GC-MS), and transformation pathways could be divided into two steps as dechlorination and hydroxylation. Electron paramagnetic resonance (EPR) technique was used to identify the generated radical species at different pH values at ambient temperature. The results showed that sulfate radicals (SO(4)(•-)) were predominant under acidic condition and hydroxyl radicals ((•)OH) were predominant under basic condition. This behavior was also confirmed by the quenching studies and kinetic model. Decreasing the solution pH resulted in increasing the degradation efficiency of 2,4,4'-CB. Moreover, the degradation of other PCBs such as 2-CB, 4-CB, 2,4-CB, 2,4'-CB, and 2,4,6-CB with persulfate was examined. The findings of this study can provide guidance in the remediation of PCBs contaminated soil and water with persulfate.
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
authors.forename: Guo-Dong
authors.initials: GD
authors.lastname: Fang
authors.forename: Dionysios D
authors.initials: DD
authors.lastname: Dionysiou
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Zhou
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiang-Dong
authors.initials: XD
authors.lastname: Zhu
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Fan
authors.forename: Long
authors.initials: L
authors.lastname: Cang
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Wang
mesh_terms: D004785:Environmental Pollutants / Q000032:analysis / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*; D013696:Temperature
chemical_list: D004785:Environmental Pollutants; D013431:Sulfates; D011078:Polychlorinated Biphenyls