High-hydrophilic and antifouling reverse osmosis membrane prepared based an unconventional radiation method for pharmaceutical plant effluent treatment

Membrane fouling is the vulnerable point of polyamide (PA) reverse osmosis (RO) membranes in industrial wastewater treatment (especially pharmaceutical plant effluent). The deposition and adsorption of foulants on the PA layer greatly reduce the permeability selectivity of the membrane and increase maintenance costs. In this work, a simple irradiation strategy was used to graft hydrophilic polymers on the membrane surface without any catalysts and initiators, and an excellent hydrophilic and antifouling modified RO membrane was developed. The successful introduction of Poly(vinyl alcohol) (PVA) onto RO membrane surface was confirmed through systematic surface characterization (13C NMR, ATR-FTIR, XPS, SEM, and AFM). The membrane M−2 with a PVA modifier concentration of 1.0% has remarkable hydrophilic properties (water contact angle of 24.93°) and excellent separation efficiency (salt rejection up to 99.4%). The antifouling property of the modified membrane is significantly enhanced due to the synergistic effect of the hydrophilic component and the roughness. In the bovine serum albumin (BSA) antifouling tests, the irreversible flux decline rate (DRir) of membrane M−2 was as low as 1.7% and the flux recovery ratio (FRR) values increased from 87.6% to 98.3% compared to pristine membrane. Importantly, the membrane modified with PVA shows a high foulant removal efficiency (COD > 99.5%) in the actual pharmaceutical plant effluent treatment, and the performance is stable after continuous operation for 28 days. The proposed simple co-grafting strategy also opens up new possibilities for the optimization or modification of other membranes (e.g., nanofiltration and ultrafiltration). Simultaneously, the prepared modified membrane has stable performance, simple and efficient method, and can also be applied in desalination and other industrial wastewater treatment fields.