title: The oxidative degradation of polystyrene resins on the removal of Cr(VI) from wastewater by anion exchange.
abstract: Cr(VI) is a powerful oxidant and is capable of oxidizing most of the organic materials. Therefore, it is possible for Cr(VI) to oxidize the polymeric resins and change the sorption properties of the resins on the removal of Cr(VI) from wastewater by anion exchange. In this study, three polystyrene resins (D201, D202, and D301) with different functional groups (-N(+)(CH3)3, -N(+)(CH3)2(C2H4OH), and N(CH3)2) were assessed on oxidation stability for Cr(VI) removal from wastewater in fixed-bed column experiments. After a 10-cycle operation, due to the oxidation of the resin, the sorption capacity of D201, D202, and D301 resins decreased by 23.5, 29.3, and 17.3%, when approximately 20-34%, 31-50%, and 18-30% of Cr(VI) was reduced to Cr(III) during each cycle respectively. The results of the Fourier transform infrared spectroscopy (FT-IR) showed that both the cleavage of CN and the formation of CO bonds occurred on the polystyrene resins during the Cr(VI) removal process. The resin simulation experiments further validated the oxidation of CC and CN bonds connected with phenethyl groups. Based upon the results from column operations and the resin simulated experiments, the oxidation mechanism of the polystyrene resin was proposed.
authors.affiliation: College of Water Sciences, Beijing Normal University, Beijing 100875, China; Technology Center for Heavy Metal Cleaner Production Engineering, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Xiao
authors.affiliation: Technology Center for Heavy Metal Cleaner Production Engineering, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: fuyuanxu@hotmail.com.
authors.forename: Fuyuan
authors.initials: F
authors.lastname: Xu
authors.affiliation: Technology Center for Heavy Metal Cleaner Production Engineering, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: jianglinhuann@163.com.
authors.forename: Linhua
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Technology Center for Heavy Metal Cleaner Production Engineering, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Dan
authors.affiliation: Technology Center for Heavy Metal Cleaner Production Engineering, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Duan
mesh_terms: D000327:Adsorption; D000837:Anion Exchange Resins / Q000737:chemistry*; D002857:Chromium / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D011137:Polystyrenes / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D014873:Water Pollutants / Q000302:isolation & purification*
chemical_list: D000837:Anion Exchange Resins; D002857:Chromium; D011137:Polystyrenes; D062065:Wastewater; D014873:Water Pollutants; C074702:chromium hexavalent ion
keywords: Cr(III); Cr(VI); Functional groups; GC–MS; Oxidative degradation