太阳光/NH2Cl体系降解微污染物的效能及动力学

利用太阳光和一氯胺(太阳光/NH₂Cl)体系降解阿司匹林((aspirin, ASA)、氟尼辛葡甲胺(flunixin meglumine, FMME)、苯甲酸(benzoic acid, BA)以及硝基苯(nitrobenzene, NB)4种代表性微污染物，探究该体系对于微污染物的降解效能以及动力学特征。结果表明，单独太阳光以及单独NH₂Cl体系对污染物几乎均无降解效果(降解率<5%)，而太阳光/NH₂Cl体系中污染物的降解效能显著提升，pH的改变对4种污染物降解效能的影响各不相同。
在实验pH条件下，以活性氮自由基和活性氯自由基为主的其他活性组分和NH₂Cl对FMME的降解起主要作用(贡献率为79.27%~89.39%)，而羟基自由基(HO·)始终是ASA的降解中贡献最大的活性组分(贡献率为44.9%~76.8%)。在酸性环境中，太阳光/NH₂Cl体系产生的消毒副产物质量浓度及毒性方面均大于单独NH₂Cl体系，而在碱性条件下其产生的消毒副产物质量浓度则明显降低，实际中应用本体系进行消毒时应考虑将pH调至碱性。

Performance and kinetics of Solar/NH2Cl system on micro-pollutant degradation

In this study, the Solar/chloramine system was used to degrade four representative micro-pollutants, including aspirin (ASA), flunixin glucosamine (FMME), benzoic acid (BA), and nitrobenzene (NB), and the degradation efficiency and kinetic characteristics of the system were investigated. The experimental results showed that both Solar alone and NH2Cl alone systems led to low removal (the degradation rate<5%). However, the degradation of the pollutants in the Solar/NH2Cl system increased significantly, and pH variation had different effects on degradation of the four pollutants. Under the experimental pH conditions, NH2Cl and other active components such as reactive nitrogen species, reactive chlorine species contributed to most FMME degradation (the contribution rate was 79.27%~89.39%), while hydroxyl radicals (HO·) made a dominant contribution to the degradation of ASA (the contribution rate was 44.
9%~76.8%). Under acidic conditions, the concentration and toxicity of disinfection by-products (DBPs) produced in Solar/NH2Cl system were higher than those in NH2Cl alone. Nevertheless, the concentration of DBPs in Solar/NH2Cl system decreased significantly under alkaline conditions. Thus, the pH should be adjusted to alkaline when this system is used to disinfect water in practice.