title: Removal of Rhodamine B under visible irradiation in the presence of Fe⁰, H₂O₂, citrate and aeration at circumneutral pH.
abstract: A new Vis-Fe(0)-H(2)O(2)-citrate-O(2) system comprising zero-valent iron, hydrogen peroxide, citrate anion and aeration at circumneutral pH under visible irradiation was studied. 21 μmol L(-1) of Rhodamine B (RhB) was chosen as the substrate to be tested. Experiments were conducted under conditions of 2.9 mmol L(-1) of H(2)O(2), 12.6g of Fe(0) and 1.0 mmol L(-1) of citrate at pH 7.5. Results showed that, in 1h reaction, 54% of RhB was removed with corresponding 26% of COD reduced. Meanwhile, the amount of released dissolved irons from Fe(0) surface was found to be at a very low level as <5.4 μmol L(-1). Extinguishing tests with isopropanol suggested that RhB oxidation by hydroxyl radicals was the main process taken place in Vis-Fe(0)-H(2)O(2)-citrate-O(2) system, which accounted for 75% of substrate removal in 3h reaction. Control and factor influencing experiments showed that the prohibitive extents of individual factor importance on RhB removal followed a decreasing order of Fe(0)>H(2)O(2)>citrate>Vis>O(2). This study showed an excellent system that could remove refractory organic compounds from water in laboratory researches, and also provided a good idea to reduce secondary contamination by dissolved irons in future investigations.
authors.affiliation: School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China. hongjun18888@163.com
authors.forename: Jun
authors.initials: J
authors.lastname: Hong
authors.forename: Sijia
authors.initials: S
authors.lastname: Lu
authors.forename: Caixiang
authors.initials: C
authors.lastname: Zhang
authors.forename: Shihua
authors.initials: S
authors.lastname: Qi
authors.forename: Yanxin
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000388:Air; D019343:Citric Acid / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D008027:Light; D010084:Oxidation-Reduction; D012235:Rhodamines / Q000737:chemistry*; D013053:Spectrophotometry; D014867:Water / Q000737:chemistry
chemical_list: D012235:Rhodamines; D014867:Water; D019343:Citric Acid; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D007501:Iron; C029773:rhodamine B