College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China.
Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
Water Res. 2022 Jul 1;219:118554. doi: 10.1016/j.watres.2022.118554. Epub 2022 May 6.
High-performance nanofiltration (NF) membrane with super antifouling capability as well as reusability is highly desired in water treatment. A new antifouling strategy by a coating-decoating-recoating cycle was investigated for effective removal of fouling and restoring the original membrane performance. The functional membrane surface was fabricated by in-situ coating a 'green' and biodegradable carboxymethyl chitosan (CMCS) layer as physical barrier. The CMCS layer can be decoated and re-coated by simple procedures. Results showed that (i) the CMCS layer enhanced surface hydrophilicity, surface smoothness and fouling resistance of NF membrane, (ii) both the unfouled and fouled CMCS layer were easily decoated by the strong acid solution, (iii) the CMCS layer was easily re-coated by facile recoating and (iv) the water flux recovery ratio of membrane with coating layer was maintained more than 88.8% during fouling testing by natural organic matter (NOM) after four sequential cycles of coating, decoating and recoating process. The re-coated membrane exhibited stable, improved membrane operational and antifouling performance. The coating-decoating-recoating approach is proven to be low-cost and eco-friendly strategy for NOM fouling control on NF membrane in water treatment applications.
在水处理中，人们非常希望得到具有超抗污染能力和可重复使用性的高性能纳滤 (NF) 膜。本研究提出了一种通过涂层-脱涂层-再涂层循环的新的抗污染策略，以有效去除污染并恢复原始膜性能。通过原位涂层“绿色”和可生物降解的羧甲基壳聚糖 (CMCS) 层作为物理屏障来制备功能膜表面。CMCS 层可以通过简单的程序进行脱涂层和再涂层。结果表明：(i)CMCS 层提高了 NF 膜的表面亲水性、表面光滑度和抗污染性；(ii)未污染和污染的 CMCS 层都可以很容易地用强酸溶液脱涂层；(iii)CMCS 层很容易再涂层；(iv)在四次涂层、脱涂层和再涂层循环后，用天然有机物 (NOM) 进行污染测试时，具有涂层的膜的水通量恢复率保持在 88.8%以上。再涂层膜表现出稳定的、改进的膜操作和抗污染性能。该涂层-脱涂层-再涂层方法被证明是一种低成本、环保的策略，可用于控制 NF 膜在水处理中的 NOM 污染。
