Abstract
Forward Osmosis (FO) has been the centre of attention across various sectors such as wastewater treatment, desalination, etc. due to its inherent advantages over pressure-driven membrane and thermal technologies. However, membrane fouling remains an unavoidable challenge that hinders its efficiency and scalability. To address this issue, effective membrane cleaning strategies are required. Yet comprehensive reviews on FO membrane cleaning remain limited despite extensive research on fouling. In this review, we first explored key fouling mechanisms in FO membranes, covering inorganic, organic, and biological fouling. We further discussed various physical and chemical cleaning methods, assessing significant factors influencing cleaning effectiveness including cleaning agent type, concentration, duration, cross-flow velocity, pH, and temperature. Additionally, emerging eco-friendly and chemical-free cleaning methods are discussed as promising alternatives to conventional techniques. Finally, we highlighted existing challenges in FO membrane cleaning and identified future research directions to support the development of more effective and sustainable cleaning practices for FO applications.
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•Comprehensive review of FO membrane fouling and cleaning strategies•Evaluates physical, chemical, and emerging eco-friendly cleaning methods•Highlights factors influencing fouling and successful cleaning outcomes•Proposes future research for more effective and sustainable FO cleaning practices