Sustainable oily water reclamation through forward osmosis assisted by fouling-resistant membranes functionalized with arginine derivatives

Purifying water contaminated with emulsified oil via forward osmosis (FO) is still plagued by low water recovery efficiency and poor fouling resistance of membrane. Herein we design a series of arginine-copper complexes to construct antifouling FO membranes from a polyamide membrane (PA-M) for oily water reclamation. A modification layer abundant in Cu 2+ and guanidino is formed on the PA selective surface. It endows the membranes with desired structural and physicochemical properties that benefit the FO separation. The membrane functionalized with copper arginine sulfate (CAS-M) outperforms PA-M with water fluxes enhanced by 151 % against DI water. CAS-M also achieves higher oil-water separation efficiency with the water recovery rate increased by 94 % compared to that of PA-M when 3000 ppm emulsified oil as the feed. Remarkably, CAS-M exhibits excellent antifouling and antibacterial performance with a 98 % antibacterial rate and easier cleaning property after being fouled. Favorable physicochemical and structural characteristics as well as advantageous water transfer properties are the major benefits of CAS-M. This makes CAS-M outperform PA-M and other recently reported FO membranes with exceptional water permeability and antifouling ability. This study demonstrates an eco-friendly protocol to develop antifouling and antibacterial FO membrane for sustainable oily water purification.