Antifouling membranes for sustainable water purification: strategies and mechanisms

Abstract

One of the greatest challenges to the sustainability of modern society is an inadequate supply of clean water. Due to its energy-saving and cost-effective features, membrane technology has become an indispensable platform technology for water purification, including seawater and brackish water desalination as well as municipal or industrial wastewater treatment. However, membrane fouling, which arises from the nonspecific interaction between membrane surface and foulants, significantly impedes the efficient application of membrane technology. Preparing antifouling membranes is a fundamental strategy to deal with pervasive fouling problems from a variety of foulants. In recent years, major advancements have been made in membrane preparation techniques and in elucidating the antifouling mechanisms of membrane processes, including ultrafiltration, nanofiltration, reverse osmosis and forward osmosis. This review will first introduce the major foulants and the principal mechanisms of membrane fouling, and then highlight the development, current status and future prospects of antifouling membranes, including antifouling strategies, preparation techniques and practical applications. In particular, the strategies and mechanisms for antifouling membranes, including passive fouling resistance and fouling release, active off-surface and on-surface strategies, will be proposed and discussed extensively.

Membranes with Surface-Enhanced Antifouling Properties for Water Purification

“…With good hydrophilicity, great adhesion to a variety of polymers and facile coating using aqueous solutions, dopamine has been widely explored to enhance the surface hydrophilicity of membranes, aiming to reduce fouling [6,32,40,41,42,43,44]. For example, PDA has been successfully coated on MF, UF and RO membranes when special procedures were developed to ensure the exposure of the membrane surface to oxygen during the coating [6,32,45].…”

Fabrication and characterization of novel antimicrobial thin film nano‐composite membranes based on copper nanoparticles

“…Advanced technologies could make a difference for millions of people around the world facing water pollution or water security. The established superiority of membrane systems over conventional separation technologies lies in the high separation efficiency, low energy consumption, small footprint, and eco‐friendliness . Nanofiltration (NF), a pressure‐driven separation process, is a promising nanotechnology increasingly applied for water treatment, e.g.…”

The Key Role of Modifications in Biointerfaces toward Rendering Antibacterial and Antifouling Properties in Polymeric Membranes for Water Remediation: A Critical Assessment

“…[7] This results in ease of release of foulants from the membrane surfaces after back-flush. [7] This results in ease of release of foulants from the membrane surfaces after back-flush.…”

“…The antibacterial activity of these compounds was studied as early as the 1900s and it was clinically been used by surgeons for sterilization. [7] Foulants adsorbed at the membrane surfaces can be removed by back-flushing and this might be the key reason due to which reports on PVDF [52,85,87,[124][125][126] and PES [127,128] based membranes modified with QACs exhibited good fouling resistance. Being a cationic agent, the mode of action is sequential and similar to that of primary amine derivatives.…”