Evaluation of membranes performance for microplastic removal in a simple and low-cost filtration system

The ubiquitous presence of microplastics (MPs) in the environment has become a major challenge in recent years. One of the main concerns is the eco-toxicological effect on marine ecosystems and the potential threat for human organs and tissues. This paper focuses on evaluating membranes performance in removing MPs within a simple, low-cost system that could be easily implemented in a domestic environment. The performance of polycarbonate, cellulose acetate, and polytetrafluoroethylene membranes with the same nominal pore size of 5 ​μm was evaluated in the removal of polyamide and polystyrene microparticles in the range of 20–300 ​μm. Their mass removal efficiency when filtering 100 ​mg/L of MPs was also calculated. A high mass removal efficiency of MPs above 94 was obtained with the three membranes. However, depending on the MPs’ nature, they could either break through the membrane or break down into smaller particle sizes. Beside size-exclusion separation, the main competing mechanisms are membrane abrasion and fouling phenomenon. Their contribution depends on the membrane properties, MPs-membrane interaction, particles’ irregularity, and transmembrane pressures employed. At comparable mass removal efficiency, the highest performing membrane material for long-term household system applications was found to be cellulose acetate.