Highly Efficient Removal of Chlorophenolic Disinfection Byproducts from Water by PMMA/PEG Asymmetric Blend Membranes

The widespread use of disinfectants has led to the generation of large amounts of harmful organic disinfection byproducts (DBPs), posing a serious threat to human health. Membrane separation technology has been extensively applied for the removal of organic pollutants from water. However, conventional nanofiltration membranes often suffer from low rejection efficiency for small neutral organic molecules due to size exclusion and charge repulsion limitations. Reverse osmosis membranes achieve higher rejection but are hindered by high energy consumption. In this work, we fabricated a series of poly(methyl methacrylate) (PMMA)/polyethylene glycol (PEG) blend membranes with different blending ratios via a simple non-solvent induced phase separation method, and systematically characterized their structure and performance. Among them, the membrane with a PMMA/PEG ratio of 8:2 exhibited an asymmetric structure featuring a dense top layer and a porous sublayer. Compared with other blend ratios, this membrane showed the best rejection performance toward four neutral chlorophenol DBPs with molecular weights ≤ 200 Da. Notably, the rejection of 2,4-dichlorophenol reached as high as 91.71%. The design and fabrication of this blend nanofiltration membrane material offers a straightforward and efficient material platform for the removal of chlorophenol DBPs from water environments.