Enhancing rejection of endocrine disrupting compounds by nanofiltration membrane: Dominant role of hydrophilic coordination barrier layer

The removal of endocrine disrupting compounds (EDCs) from water/wastewater is of significant importance. However, current nanofiltration (NF) membranes exhibit limited water permeance and hydrophobic EDCs rejection rates. Herein, we fabricated a novel NF membrane intercalated with the 3,4-dihydroxyphenylalaninevanadium (DOPA-V) complex barrier layer. The DOPA-V intercalated NF membrane possessed a notable water permeance of similar to 38 L center dot m(-2)center dot h(-1)center dot bar(-1), thanks to the formation of a thin and loosely structured PA layer in comparison to the control, as well as the gutter effect optimizing the pathway of water molecule transport induced by the DOPA-V layer. The rejections of methylparaben, nonylphenol, bisphenol AF, propiconazole, dioctyl phthalate, and heptachlorobiphenyl by the DOPA-V intercalated NF membrane were both enhanced compared with those of the control. The enhanced rejection of hydrophobic EDCs by the DOPA-V intercalated NF membrane was primarily dominated by the barrier role of DOPA-V layer. According to the resistance-in-series model, DOPA-V predominated the membrane resistance to hydrophobic EDCs, resulting in a reduction of 68.8%, 76.5%, 58.0%, 58.1 %, 63.0 %, and 72.0 %, respectively, in the diffusion rates of those hydrophobic EDCs compared to the control. This research offers a novel strategy on customizing NF membranes to effectively remove specific trace organic contaminants from water/wastewater.