Bio-functional collagen/casein/chitosan scaffolds regulated porous TFC membrane for acid recovery

Applications of environmentally friendly and low-cost biomaterials for membrane preparation offer unparalleled advantages over traditional synthetic polymer membrane. Herein, a novel collagen/casein/chitosan composite material was designed to synthesize TFC membrane for acid recovery from acidic waste stream. A vacuum filtration method was used to precious adjust the thickness of the functional layer while glutaraldehyde was adopted as crosslinking agent to preserve surface charge property of anion-exchange membranes (AEM) at acidic conditions. The electrostatic interactions and hydrogen bonding of these biopolymers endowed the TFC membrane with enhanced stability. At optimized conditions with 0.15 mL collagen/casein/chitosan composites decoration, the TFC membrane with a functional layer thickness of around 628.4 nm exhibited an excellent acid permeance (U H +  = 0.034 m h −1 ) and a high H + / Fe 2+ separation factor up to 33.8. This facile strategy provides a useful guideline for constructing highly efficient TFC membrane for acid recovery and broadens the application of biomaterials for membrane application at harsh environments.