Recent advances in membranes modified with plant polyphenols in wastewater treatment: A review

Membrane separation technology usually faces challenges such as membrane fouling, a short lifespan, and a "trade-off" between permeability and selectivity when treating wastewater. Plant polyphenols, as an environmentally friendly material with various excellent physicochemical properties, are increasingly being used as membrane modification materials to solve the problems of membrane processes. In this review, the structure and properties of plant polyphenols are first briefly introduced. The methods and mechanisms of membrane modification by plant polyphenols are further summarized and compared. Then, the discussion focuses on the enhancement of membrane properties by sole modification of plant polyphenols and composite modification with other materials (i.e., metal ions, organics, and nanomaterials). The plant polyphenol-modified membranes effectively enhanced membrane properties such as high-flux selectivity, antifouling, antibacterial, and antioxidant. Moreover, future perspectives on additional plant polyphenols, underlying mechanisms, and practical application of plant polyphenol-modified membranes are prospected. This review aims to summarize existing research on the remarkable performance of plant polyphenol-modified membranes in separating wastewater contaminants and provide some useful insights into the modification of environmentally friendly materials to enhance membrane performance.