UV/H_2O_2氧化处理水中去污剂

表面活性剂是一类特殊的有机污染物,在去污、洗衣、印染等废水中广泛存在.本文以某电厂实用的5种去污剂为研究对象,考察了UV/H2O2对5种去污剂的矿化能力,研究了H2O2和去污剂初始浓度、初始p H值、去污剂种类、辐照时间等因素对氧化效果的影响.结果表明,5种去污剂在254 nm处均无较强吸收,单独UV辐照对其降解效果不明显.当去污剂初始DOC浓度为50 mg·L-1,H2O2最佳投加量为1 m L·L-1,反应时间为90 min时,对5种去污剂的矿化率(即DOC去除率)在53%~87%,矿化率随去污剂种类的不同而不同.对去污剂的矿化率随着UV辐照时间的延长而增大,去除率曲线符合一级反应动力学方程.废水初始p H值对氧化效果的影响不显著,H2O2/DOC比值对氧化效果有显著影响.研究表明,UV/H2O2技术能高效矿化水中的去污剂,H2O2/DOC比值和UV辐照时间是影响氧化效率的关键因素.

Oxidation of detergents in water by UV/H2O2

Surfactants are special organic pollutants and exist widely in decontamination, laundry and dyeing wastewater. In this study, the mineralization characteristics of five detergents used in a power plant were investigated using UV/H₂O₂ technology. The effects of initial concentration of H₂O₂ and surfactants, initial pH values, surfactant species and UV irradiation time were evaluated. All 5 detergents had no characteristic adsorption at 254 nm, and no obvious degradation was detected with UV irradiation only. When the initial DOC concentrations of detergents were 50 mg·L^-1, the best conditions were with the initial H₂O₂ of 1 mL·L^-1 and reaction time of 90 min. The DOC removals were 53%~87% and varied with the detergent species. The mineralization (removal of DOC) increased with UV irradiation time, and the reaction fit a first order kinetic model. The initial pH value had no significant effect on the oxidation processes, but the H₂O₂/DOC value obviously affected the DOC removal ratios. Based on this study, UV/H₂O₂ was effective in oxidizing detergents in water, during which H₂O₂/DOC value and UV irradiation time were key factors.