title: Enhanced catalytic degradation of ciprofloxacin with FeS2/SiO2microspheres as heterogeneous Fenton catalyst: Kinetics, reaction pathways and mechanism.
abstract: In this study, the application of FeS2/SiO2microspheres as a catalyst to activate H2O2for the degradation of ciprofloxacin (CIP) was systematically investigated. Results demonstrated that the presence of SiO2microspheres on the surface of FeS2could effectively make the reaction of aqueous Fe2+and H2O2smoothly continuous by controlling the release of aqueous Fe2+from FeS2. Nearly 100% of CIP was degraded after 60min under the optimum conditions. A superior performance on the CIP degradation and high reusability of the catalyst was obtained in FeS2/SiO2microspheres activated H2O2system. A low concentration of ethylene diamine tetraacetie acid (EDTA) did positively affect the degradation rate of CIP. A synergetic effect between adsorption and oxidation processes contributed to the significant enhancement of CIP degradation. Seven oxidation intermediates were identified during the CIP degradation process, and the direct HO oxidation proved to be a main CIP degradation pathway. For degradation pathway of CIP, oxidation of piperazine ring would be its first step, followed by cleavage of the heterocyclic ring. Subsequently, the substitution, hydroxylation and decarboxylation processes occurred. This is the first report on the feasibility of FeS2/SiO2microspheres activated H2O2system for the enhanced degradation of CIP.
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: Research Resources Center, South China Normal University, Guangzhou 510631, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Jiang
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: Gang
authors.initials: G
authors.lastname: Li
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: Jin-Jun
authors.initials: JJ
authors.lastname: Liu
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: Lin-Zi
authors.initials: LZ
authors.lastname: Zuo
mesh_terms: D002384:Catalysis; D002939:Ciprofloxacin / Q000737:chemistry*; D003653:Decarboxylation; D004492:Edetic Acid; D005296:Ferrous Compounds / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006900:Hydroxylation; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008863:Microspheres; D059027:Recycling; D012822:Silicon Dioxide / Q000737:chemistry*; D014874:Water Pollutants, Chemical
chemical_list: C045076:Fenton's reagent; D005296:Ferrous Compounds; D014874:Water Pollutants, Chemical; D002939:Ciprofloxacin; D012822:Silicon Dioxide; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D007501:Iron; C022597:ferrous sulfide
keywords: Ciprofloxacin; Degradation; FeS(2)/SiO(2); Fenton-like process; H(2)O(2)