title: Sulfate radical-induced degradation of Acid Orange 7 by a new magnetic composite catalyzed peroxymonosulfate oxidation process.
abstract: We synthesized a novel magnetic composite, Fe3O4/Cu(Ni)Cr-LDH, as a heterogeneous catalyst for the degradation of organic dyes in the solution using sulfate radical-based advanced oxidation processes. The physicochemical properties of the composite synthesized via two-step microwave hydrothermal method were characterized by several techniques, such as X-ray diffraction (XRD), inductively coupled plasma (ICP), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The degradation tests were performed at 25°C with Acid Orange 7 (AO7) initial concentration of 25mg/L and AO7/peroxymonosulfate (PMS) molar ratio of 1:10, which showed that the complete degradation by Fe3O4/Cu1.5Ni0.5Cr-LDH could be achieved and the mineralization rate could reach 46%. PMS was activated by Cu (II) and Fe (II/III) of Fe3O4/Cu(Ni)Cr-LDH to generate sulfate radicals (SO4(-)). Subsequently, the organic functional groups of AO7 molecules were destroyed by sulfate radicals (SO4(-)), inducing the degradation of AO7. Moreover, the catalytic behavior of the catalysts could be reused five times. Therefore, our work suggested that the Fe3O4/Cu(Ni)Cr-LDH composite could be applied widely for the treatment of organic dyes in wastewater.
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Chen
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, PR China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Ma
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, PR China.
authors.forename: Jizhi
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Earth and Environmental Engineering, Columbia University, West 120th Street, New York, NY 10027, USA.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, PR China. Electronic address: grqian@shu.edu.cn.
authors.forename: Guangren
authors.initials: G
authors.lastname: Qian
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D001557:Benzenesulfonates / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry*; D008280:Magnetics; D009532:Nickel / Q000737:chemistry; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D005290:Ferric Compounds; D005609:Free Radicals; D010545:Peroxides; D013431:Sulfates; C000499:ferric oxide; C038288:peroxymonosulfate; D003300:Copper; D009532:Nickel; C014722:2-naphthol orange
keywords: Acid Orange 7; Fe(3)O(4)/layered double hydroxide; Oxidative degradation; Peroxymonosulfate; Sulfate radicals