Mineral scaling in membrane desalination: Mechanisms, mitigation strategies, and feasibility of scaling-resistant membranes

Mineral scaling is one of the primary factors that constrain the performance of membrane desalination. However, compared to numerous studies on organic and biological fouling, less effort has been invested in understanding the mechanisms of mineral scaling. Although anti-fouling membranes have been successfully fabricated to mitigate organic and biological fouling, little progress has been made on the design and fabrication of scaling-resistant membranes. In this review, we discuss the occurrence and consequences of mineral scaling in different membrane desalination processes, and emphasize the complex nature of membrane scaling regulated by feed-water chemistry. We describe established theories associated with mineral scaling, and highlight the knowledge and technology advances in the field of biomineralization that demonstrates the important role of surface chemistry in controlling mineral formation. Current strategies of scaling mitigation are predominantly independent of membrane materials, while the feasibility of developing scaling-resistant membranes has been indicated but not fully achieved in the literature. Accordingly, potential design strategies and challenges associated with the development of novel membrane materials with improved scaling resistance are discussed, and future research needs are proposed.