Liu Yi, Lin Bo, Liu Wenchao, Li Junjun, Gao Congjie, Pan Qiaoming
The Second Institute of Oceanography of the State Oceanic Administration Hangzhou 310012 China.
Hangzhou Water Treatment Technology Research and Development Center Hangzhou 310012 China
RSC Adv. 2018 Oct 29;8(64):36430-36440. doi: 10.1039/c8ra06755d. eCollection 2018 Oct 26.
High water flux, good separation property and excellent chlorine resistance are crucial factors affecting the development of nanofiltration (NF) membranes. To obtain these properties, NF membranes were fabricated interfacial polymerization using -xylylenediamine (-XDA) and polyethyleneimine (PEI) as aqueous monomers. By controlling the concentration ratio of -XDA and PEI in the aqueous solution, it was found that the addition of PEI to the aqueous solution can increase the rejection of the NF membrane to magnesium chloride (MgCl) and magnesium sulfate (MgSO) from 18.3%, 54.5% to 84.4%, 94.1%, respectively. Meanwhile, the rejection to sodium sulphate (NaSO) and sodium chloride (NaCl) remain essentially unchanged. On the other hand, the addition of -XDA to the aqueous solution can improve the chlorine resistance of the NF membrane, but it decreased the water flux of NF membrane. Sodium hypochlorite (NaClO) solution was used to evaluate chlorine resistance of NF membranes. After 10 000 ppm h NaClO immersion, the rejections to NaSO of NF membranes prepared from the pure -XDA and the blend of -XDA and PEI were basically unchanged and the water flux increased. In conclusion, the obtained membranes not only exhibited good separation performance but also had good chlorine resistance.
高水通量、良好的分离性能和出色的耐氯性是影响纳滤（NF）膜发展的关键因素。为了获得这些性能，采用间苯二甲二胺（-XDA）和聚乙烯亚胺（PEI）作为水相单体通过界面聚合法制备了纳滤膜。通过控制水溶液中 -XDA 和 PEI 的浓度比，发现向水溶液中添加 PEI 可使纳滤膜对氯化镁（MgCl）和硫酸镁（MgSO）的截留率分别从 18.3%、54.5%提高到 84.4%、94.1%。同时，对硫酸钠（NaSO）和氯化钠（NaCl）的截留率基本保持不变。另一方面，向水溶液中添加 -XDA 可提高纳滤膜的耐氯性，但会降低纳滤膜的水通量。使用次氯酸钠（NaClO）溶液评估纳滤膜的耐氯性。在 10000 ppm·h 的 NaClO 浸泡后，由纯 -XDA 以及 -XDA 与 PEI 的混合物制备的纳滤膜对 NaSO 的截留率基本不变，且水通量增加。总之，所制备的膜不仅表现出良好的分离性能，而且具有良好的耐氯性。
