Construction of solvent resistance O-PASS@UiO-66-NH2/O-PASS composite membrane for methylene blue removal

The purification of dye wastewater plays a critical role in water pollution treatment. Adsorption is a cheap and effective separation technology but is limited by the reuse of adsorption materials. Ultrafiltration membranes have a relatively high flux but their pores are too large to reject small dye molecules. In this study, negatively charged oxidized poly (arylene sulfide sulfone) (O-PASS) membrane, NMP pretreatment oxidized O-PASS (N-O-PASS) membrane, and O-PASS@UiO-66-NH2/O-PASS composite membranes were fabricated to retain cationic methylene blue (MB) from wastewater by combining ultrafiltration and adsorption techniques. The increased porosity of the N-O-PASS membrane provides more available adsorption sites for an equilibrium MB adsorption amount of 22.5 (mg g(-1)) and 100% rejection in the first 10 min during ultrafiltration with a pure water flux of 162.32 (L m(-2) h(-1) bar(-1)). Due to the enhanced hydrophilicity and separating property by deposited UiO-66-NH2 particles and PASS resin, O-PASS@UiO-66-NH2/O-PASS composite membrane shows a flux of 170.32 (L m(-2) h(-1) bar(-1)) and a 100% MB rejection in 60 min with great reusability. The O-PASS@UiO-66-NH2/O-PASS composite membrane is a new promising membrane for the removal of dyes from wastewater. Meanwhile, the superior solvent resistance endows it great adaptability in wide applications, especially in harsh conditions.

Automated summary

This study successfully removed dyes from wastewater by combining ultrafiltration and adsorption techniques using different membrane materials. The N-O-PASS membrane with increased porosity provided more adsorption sites and higher ultrafiltration flux. The O-PASS@UiO-66-NH2/O-PASS composite membrane achieved complete dye rejection in 60 minutes and demonstrated great reusability. It also showed superior solvent resistance, making it suitable for a wide range of applications, especially in harsh conditions.