Double positively charged polyamide nanofiltration membrane with PEI/Zr4+ for Cr3+ and trimethoprim removal

This paper focuses on the functionalization of double positively charged polyethylenimine (PEI)/Zr4+-polyamide (PA) nanofiltration (NF) membrane by connecting Zr4+ with positively charged PEI-PA NF membrane surface. In particular, the properties of prepared PEI/Zr4+-PA NF membrane, performance on removing aquatic contami-nants (Cr3+ and trimethoprim), and its antifouling ability were evaluated in detail. In this regard, zirconium acetate was successfully adopted as the zirconium source for stable membrane surface charge control. Zr4+ loading increased the hydrophilicity of the PEI-PA NF membrane, improved permeate flux, and enhanced the removal behavior of PEI/Zr4+-PA NF membrane especially when exposed to Cr3+ and trimethoprim at high concentrations. Furthermore, effectiveness of PEI/Zr4+-PA NF membrane was not affected by high filtering de-gree, filtration cycle, and negatively charged macromolecules, such as bovine serum albumin (BSA). Also, antifouling ability of PEI/Zr4+-PA NF membrane could be further improved by continuously loading Zr4+.

Automated summary

This paper focuses on the functionalization of double positively charged polyethylenimine (PEI)/Zr4+-polyamide (PA) nanofiltration (NF) membrane. The study evaluates the properties and performance of prepared PEI/Zr4+-PA NF membrane in removing aquatic contaminants and its antifouling ability. Results show that loading Zr4+ improves the hydrophilicity and removal behavior of the membrane when exposed to high concentrations of contaminants. The effectiveness of the membrane is not affected by factors such as high filtering degree and filtration cycle, and antifouling ability can be further improved by continuously loading Zr4+.