Chemical Cleaning of Ultrafiltration Membrane Fouled by Humic Substances: Comparison between Hydrogen Peroxide and Sodium Hypochlorite
Chemical Cleaning of Ultrafiltration Membrane Fouled by Humic Substances: Comparison between Hydrogen Peroxide and Sodium Hypochlorite
复制标题
腐殖质污染超滤膜的化学清洗：过氧化氢与次氯酸钠的比较
DOI：
10.3390/ijerph16142568
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发表时间：
2019-07-02
影响因子：
--
通讯作者：
Zhang, Shujia
中科院分区：
文献类型：
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作者：
Li, Kai;Li, Shu;Zhang, Shujia
化学清洗是水处理超滤系统可持续运行的必要条件。次氯酸钠（NaClO）是用于受到有机物和微生物污染的膜的既定清洁剂，但在NaClO清洁期间产生有毒卤化副产物的问题已经引起关注。过氧化氢（H2 O2）是一种潜在的“绿色”清洗剂，可以避免卤化副产物的形成。本文在较宽的pH范围内，研究了H_2O_2和NaClO对腐殖酸污染超滤膜的清洗效果，并考察了腐殖酸与清洗剂反应后的性质变化。在pH 3-9时，H2 O2的清洗效率低于NaClO的清洗效率，但在pH 11时，H2 O2的清洗效率提高到与NaClO相当的水平（91.4%）。由于与清洗剂反应，HS的性质和污垢潜力的变化程度与其清洗效果一致。H2 O2处理在pH 11显着增加HS分子的负电荷，分解高分子量的分子，并降低其污垢的潜力。因此，从清洗废液的处理和清洗效果两方面考虑，强碱条件下的H2 O2清洗是HS污染膜的一种较好选择。
Chemical cleaning is indispensable for the sustainable operation of ultrafiltration (UF) system in water and wastewater treatment. Sodium hypochlorite (NaClO) is an established cleaning agent for membranes subject to organic and microbial fouling, but concerns have been raised about the generation of toxic halogenated by-products during NaClO cleaning. Hydrogen peroxide (H2O2) is a potential “green” cleaning agent that can avoid the formation of halogenated by-products. In this work, cleaning efficacy of H2O2 and NaClO for UF membrane fouled by humic substances (HS) was evaluated under a wide pH range, and change of HS’s properties due to reaction with cleaning agents was examined. The cleaning efficacy of H2O2 was lower than that of NaClO at pH 3–9, but it increased to a level (91.4%) comparable with that of NaClO at pH 11. The extents of changes in properties and fouling potential of HS due to reacting with cleaning agents were consistent with their cleaning efficacy. H2O2 treatment at pH 11 significantly increased negative charge of HS molecules, decomposed high-MW molecules, and reduced its fouling potential. Therefore, considering treatment/disposal of cleaning waste and cleaning efficacy, H2O2 cleaning under strong alkaline condition can be a good choice for HS-fouled membrane.