title: Ibuprofen degradation and toxicity evolution during Fe2+/Oxone/UV process.
abstract: This study shows the degradation of ibuprofen in aqueous solution using oxone process mediated by Fe2+with UV irradiation (FOU). Fe2+/Oxone (FO), Fe2+/UV (FU), Oxone/UV (OU) processes were investigated separately to elucidate the role of different conditions in the processes. The effects of UV wavelength, the dosage of Fe2+, the dosage of oxone, initial target compound concentration, solution pH and anions on the degradation efficiency were studied. In general the FOU is best performed among the processes. About 97% of 0.05 mM ibuprofen was removed in 10 min, under the optimal conditions of FOU (wavelength = 300 nm, [Fe2+]0= 0.25 mM, [Oxone]0= 0.25 mM, and pH = 3.68). Subsequent tests like the mineralization efficiency and toxicity evolution were also conducted to ensure the FOU is a safe and comprehensive treatment process after the ibuprofen is removed. However, the above optimal conditions for IBP degradation were found inadequate in the TOC and toxicity tests. After cross examining the test results and intermediates, it was found that the low TOC and toxicity removal was mainly due to the accumulation of toxic intermediates in the solution. It is therefore suggested that a stepwise introduction of Fe2+and oxone (to control the radical concentration at a lower level, so as to minimize the futile consumption of radicals) with an elevated dosage of [IBP]0:[Fe2+]0:[Oxone]0to 1:25:25 (to effectively degrade the unwanted intermediates at the later stage of reaction) is an efficient approach to ensure the TOC removal and toxicity elimination in FOU.
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Han
authors.initials: H
authors.lastname: Gong
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Electronic address: wei.chu@polyu.edu.hk.
authors.forename: Wei
authors.initials: W
authors.lastname: Chu
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: So Hiu
authors.initials: SH
authors.lastname: Lam
authors.affiliation: Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Angela Yu-Chen
authors.initials: AY
authors.lastname: Lin
mesh_terms: D000818:Animals; D005296:Ferrous Compounds / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007052:Ibuprofen / Q000737:chemistry* / Q000633:toxicity*; D010084:Oxidation-Reduction; D012403:Rotifera / Q000187:drug effects; D012996:Solutions; D013464:Sulfuric Acids / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry
chemical_list: D005296:Ferrous Compounds; D012996:Solutions; D013464:Sulfuric Acids; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; C048813:potassium peroxymonosulfuric acid; D007052:Ibuprofen
keywords: Degradation; Fe(2+)/Oxone/UV process; Ibuprofen; Toxicity