title: Simultaneous removal of Cr(VI) and phenol by persulfate activated with bentonite-supported nanoscale zero-valent iron: Reactivity and mechanism.
abstract: The applicability of bentonite-supported nanoscale zero-valent iron (B-nZVI) as a catalyst to activate persulfate (PS) for the simultaneous removal of Cr(VI) and phenol was systematically investigated in this study. Experimental results demonstrated that phenol degradation was significantly enhanced under acidic condition and with oxygen supply, whereas the Cr(VI) reduction was not obviously declined. The removal efficiencies of Cr(VI) and phenol in B-nZVI/PS combined system were 99.8 and 72.3%, respectively. Cr(VI) reduction and phenol oxidation was simultaneously achieved in B-nZVI/PS combined system, which provided a promising environmental treatment for industrial wastewater containing metal ions and organic compounds. An acidic condition was more favorable to the decomposition of persulfate for the production of sulfate radicals. Radical scavenging tests revealed that the predominant reactive oxygen species for phenol degradation was SO4(-), neither HO nor O2(-). A reaction mechanism, which involves the Cr(VI) removal mainly by the reduction of nZVI and the degradation of phenol mainly by the SO4(-) from the decomposition of persulfate, was proposed. These findings revealed that B-nZVI/PS combined system has a potential in the environmental remediation polluted jointly by organic compounds and/or heavy metals.
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors.forename: Zeng-Hui
authors.initials: ZH
authors.lastname: Diao
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. Electronic address: xuxr@scsio.ac.cn.
authors.forename: Xiang-Rong
authors.initials: XR
authors.lastname: Xu
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: Research Resources Center, South China Normal University, Guangzhou 510631, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Jiang
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Yu-Xi
authors.initials: YX
authors.lastname: Yang
authors.affiliation: School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China.
authors.forename: Ling-Jun
authors.initials: LJ
authors.lastname: Kong
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors.forename: Yu-Xin
authors.initials: YX
authors.lastname: Sun
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yong-Xia
authors.initials: YX
authors.lastname: Hu
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Qin-Wei
authors.initials: QW
authors.lastname: Hao
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
keywords: Cr(Ⅵ); Fenton-like process; Nano zero-valent iron; Phenol; Synergistic effect