title: Humic acid coated Fe3O4 magnetic nanoparticles as highly efficient Fenton-like catalyst for complete mineralization of sulfathiazole.
abstract: Humic acid coated Fe(3)O(4) magnetic nanoparticles (Fe(3)O(4)/HA) were prepared for the removal of sulfathiazole from aqueous media. Fe(3)O(4)/HA exhibited high activity to produce hydroxyl (OH) radicals through catalytic decomposition of H(2)O(2). The degradation of sulfathiazole was strongly temperature-dependent and favored in acidic solution. The catalytic rate was increased with Fe(3)O(4)/HA dosage and H(2)O(2) concentration. When 3 g L(-1) of Fe(3)O(4)/HA and 0.39 M of H(2)O(2) were introduced to the aqueous solution, most sulfathiazole was degraded within 1h, and >90% of total organic carbon (TOC) were removed in the reaction period (6h). The major final products were identified as environmentally friendly ions or inorganic molecules (SO(4)(2-), CO(2), and N(2)). The corresponding degradation rate (k) of sulfathiazole and TOC was 0.034 and 0.0048 min(-1), respectively. However, when 3 g L(-1) of bare Fe(3)O(4) were used as catalyst, only 54% of TOC was eliminated, and SO(4)(2-) was not detected within 6h. The corresponding degradation rate for sulfathiazole and TOC was 0.01 and 0.0016 min(-1), respectively. The high catalytic ability of Fe(3)O(4)/HA may be caused by the electron transfer among the complexed Fe(II)-HA or Fe(III)-HA, leading to rapid regeneration of Fe(II) species and production of OH radicals.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology of Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Hongyun
authors.initials: H
authors.lastname: Niu
authors.forename: Di
authors.initials: D
authors.lastname: Zhang
authors.forename: Shengxiao
authors.initials: S
authors.lastname: Zhang
authors.forename: Xiaole
authors.initials: X
authors.lastname: Zhang
authors.forename: Zhaofu
authors.initials: Z
authors.lastname: Meng
authors.forename: Yaqi
authors.initials: Y
authors.lastname: Cai
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry; D002244:Carbon; D002384:Catalysis; D052918:Environmental Restoration and Remediation; D052203:Ferrosoferric Oxide / Q000737:chemistry; D006812:Humic Substances; D006861:Hydrogen Peroxide / Q000737:chemistry; D017665:Hydroxyl Radical; D007700:Kinetics; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D000077589:Sulfathiazole; D013432:Sulfathiazoles / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D006812:Humic Substances; D058185:Magnetite Nanoparticles; D013432:Sulfathiazoles; D017665:Hydroxyl Radical; D002244:Carbon; D006861:Hydrogen Peroxide; D052203:Ferrosoferric Oxide; D000077589:Sulfathiazole