title: Removal and degradation pathway study of sulfasalazine with Fenton-like reaction.
abstract: The Fenton-like degradation of sulfasalazine solution is studied in this work. The effects of reaction parameters such as Fe(3+) concentration, initial H(2)O(2) dosage and the reaction temperature are evaluated. For sulfasalazine of 100mg/L, the removal of sulfasalazine, chemical oxygen demand (COD) and total organic carbon (TOC) reached 99.5%, 84.2% and 41% in 60 min with 0.20mM Fe(3+) and 16 mM H(2)O(2) at 35°C, respectively. The complexed Fe(3+) presents a reaction constant of 0.062 min(-1)mM(-1) while that of free Fe(3+) is 2.526 min(-1)mM(-1) for sulfasalazine degradation. LC-MS technology was used to analysis the possible degradation intermediates. The degradation of sulfasalazine principally begins with the attack of hydroxyl radical on the azo-group as well as the sulfanilamido group. Both intramolecular rearrangement and bimolecular reaction occur simultaneously after the hydroxyl radical attack. Further attack of the active oxidative species results in the cleavage of the aromatic rings and the production of CO(2). The degradation of industrial sulfasalazine wastewater with a COD of 3425 mg/L has also been achieved by Fenton reaction with different dosage of H(2)O(2). Relatively better removal efficiency is observed at moderate Fe/H(2)O(2) molar ratio from 1/5 to 2/5 for industrial sulfasalazine wastewater treatment.
authors.affiliation: Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, PR China. fxq5566@163.com
authors.forename: Xiangqun
authors.initials: X
authors.lastname: Fan
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Hao
authors.forename: Xingxing
authors.initials: X
authors.lastname: Shen
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Jinlong
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D002245:Carbon Dioxide; D002851:Chromatography, High Pressure Liquid; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007220:Industrial Waste; D007700:Kinetics; D013058:Mass Spectrometry; D010100:Oxygen / Q000737:chemistry; D012996:Solutions; D012460:Sulfasalazine / Q000737:chemistry*; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D007220:Industrial Waste; D012996:Solutions; D014874:Water Pollutants, Chemical; D002245:Carbon Dioxide; D012460:Sulfasalazine; D002244:Carbon; D006861:Hydrogen Peroxide; D010100:Oxygen