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.