Backpulsing technology applied in MF and UF processes for membrane fouling mitigation: A review

Membrane cleaning is crucial to maintain the permeability and selectivity of membranes. Physical cleaning can mitigate membrane fouling, lower the frequency of chemical cleaning, thus prolong membrane lifetime, and reduce operational costs. Backpulsing is a promising physical cleaning method, which can effectively mitigate external and non-adhesive fouling and has been used in many industrial fields. However, a comprehensive understanding of backpulsing and the optimization of this technology is still lacking. This paper critically reviews the development of backpulsing technique in microfiltration (MF) and ultrafiltration (UF) processes. Firstly, the fundamentals of backpulsing are addressed. Secondly, applications of backpulsing are summarized according to the applied fields. Results of pilot-and commercial-scale operations are presented. Moreover, factors influencing backpulsing efficiency are illustrated, including feed properties, membrane properties and operating parameters. Furthermore, mathematical models of backpulsing are overviewed. The models not only predict membrane productivity, but also provide a perspective to evaluate the performance of backpulsing in fouling mitigation. Finally, the existing challenges and future outlook are discussed.