From characterisation to strategy: A comprehensive review of fouling in dairy ultrafiltration and microfiltration

Membrane-based separation technologies like ultrafiltration (UF) and microfiltration (MF) are widely used for concentrating and separating proteins and other milk components. Despite significant advancements, fouling remains a major challenge, increasing operational costs, processing time, and energy consumption. This review thoroughly examines fouling characterisation in milk UF and MF processes, focusing on the interplay between membrane properties, operating conditions and solution properties. The review highlights the critical need for effective fouling mitigation strategies. It provides an in-depth analysis of fouling properties, factors influencing filtration, and advanced techniques for characterisation. The discussion also addresses the optimisation of cleaning procedures, emphasising the importance of understanding the chemical and morphological characteristics of fouling to develop tailored cleaning protocols. Such customised approaches can result in reduced standard cleaning sequences, leading to the conservation of water and chemicals. The review suggests future research directions, emphasising the importance of collaboration between dairy processors and cleaning agent suppliers to enhance cleaning strategies. It highlights the necessity of employing multiple analytical techniques to comprehensively understand fouling, linking it with filtration performance data from real processes.