次氯酸钠（NaClO）溶液已被广泛用于恢复污损膜的通量。本文中膜通量的测试还表明，通过在离线模式下将其混入NaClO溶液中，可以有效地清洁腐殖酸污染的膜。但是，发现在用NaClO溶液化学清洗膜结垢的过程中会形成有毒的卤化副产物。除TCE和MCAA外，所有卤化副产物均随HA浓度的增加而显着增加。随着化学清洁时间的延长，生成的水合氯醛（CH）和三氯乙酸（TCAA）的浓度单调上升，而氯仿（TCM），三氯乙腈（TCAN），三氯乙烯（TCE），三氯硝基甲烷（TCNM）则明显增加，并且然后减少模式。形成的TCM，TCAA和1,1-二氯-2-丙酮（1，1-DCP）对NaClO浓度表现出明显的正依赖性，这与二氯乙腈（DCAN）和1,1,1-三氯-2-丙酮（TCP）的形成相反。随着混合pH值的增加，TCM和CH均明显增加，而卤代乙酸（HAAs）和卤代乙腈（HANs）则持续下降。总体而言，与温度稳定在15-35°C范围内的不稳定副产物相比，相对稳定的卤代副产物在较高温度下受到青睐。当使用中分子量截止（3 kDa和5 kDa）的膜时，发现1,1-DCP，TCNM，TCM和TCAA更容易形成。钙离子（Ca TCM和CH均明显增加，而卤代乙酸（HAAs）和卤代乙腈（HANs）持续下降。总体而言，与温度稳定在15-35°C范围内的不稳定副产物相比，相对稳定的卤代副产物在较高温度下受到青睐。当使用中分子量截止（3 kDa和5 kDa）的膜时，发现1,1-DCP，TCNM，TCM和TCAA更容易形成。钙离子（Ca TCM和CH均明显增加，而卤代乙酸（HAAs）和卤代乙腈（HANs）持续下降。总体而言，与温度在15-35°C范围内的不稳定副产物相比，相对稳定的卤代副产物在较高温度下受到青睐。当使用中分子量截止（3 kDa和5 kDa）的膜时，发现1,1-DCP，TCNM，TCM和TCAA更容易形成。钙离子（Ca 发现使用中分子量截止（3 kDa和5 kDa）的膜时，TCM和TCAA更容易形成。钙离子（Ca 发现使用中分子量截止（3 kDa和5 kDa）的膜时，TCM和TCAA更容易形成。钙离子（Ca2+）还影响了卤化副产物的形成，其结果是，在10 mg / L的Ca 2+浓度下，大量副产物被大量还原。这项研究表明，处理完膜后残留的NaClO溶液将含有一些有毒的副产物，应仔细处理。

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Sodium hypochlorite (NaClO) solution has been widely used to restore the flux of fouled membrane. The test of membrane flux herein also suggests that humic acid-fouled membranes could be efficiently cleaned by blending in NaClO solution at off-line mode. However, toxic halogenated by-products were found to form during the chemical cleaning of membrane fouling by NaClO solution. All the halogenated by-products except TCE and MCAA rose significantly with the increase of HA concentration. With prolonged chemical-cleaning time, the concentrations of formed chloral hydrate (CH) and trichloroacetic acid (TCAA) rose monotonically, while chloroform (TCM), trichloroacetonitrile (TCAN), trichloroethylene (TCE), trichloronitromethane (TCNM) followed an obvious increasing and then decreasing pattern. The formed TCM, TCAA and 1,1-dichloro-2-propanone (1,1-DCP) show obvious positive dependences on NaClO concentration, which was contrary to the formation of dichloroacetonitrile (DCAN) and 1,1,1-trichloro-2-propanone (TCP). With increasing the blending pH, both TCM and CH increased apparently, while haloacetic acids (HAAs) and haloacetonitriles (HANs) decreased continuously. Overall, the relatively stable halogenated by-products were favored at higher temperature compared to the unstable ones in the temperature range of 15–35 °C. 1,1-DCP, TCNM, TCM and TCAA were found to be easier to form when using the membranes with medium molecular weight cutoff (3 kDa and 5 kDa). The presence of calcium ions (Ca2+) also affected the formation of halogenated by-products as a result that lots of them were significantly reduced at a Ca2+ concentration of 10 mg/L. This study suggests that the remained NaClO solution after treatment of fouled membrane would contain some toxic by-products and should be carefully treated.