A comprehensive review of RO membrane fouling: Mechanisms, categories, cleaning methods and pretreatment technologies

As the global water crisis intensifies, reverse osmosis (RO) membranes play a pivotal role in desalination and industrial water treatment. However, membrane fouling significantly hampers their effectiveness, reducing water quality and production rates while increasing operational costs and maintenance demands. This review addresses the critical gaps in understanding the mechanisms of fouling, categorizing it into four distinct types: inorganic scaling, organic fouling, biofouling, and colloidal fouling, each presenting unique challenges to membrane performance. We delve into both external and internal fouling mechanisms, highlighting how contaminants obstruct membranes through different pathways. Additionally,…