Optimization of waste plastic reutilized polymeric membrane fabrication for efficient wastewater treatment

Abstract

The escalating global production of plastic waste and the urgent need for clean water presents profound environmental and sustainability concerns. Repurposing waste plastic into value-added products, such as polymeric membranes for ultrafiltration applications, offers a promising avenue for addressing these challenges. This study focuses on utilizing waste polystyrene (PS) to synthesize membranes via non-solvent induced phase separation method. Through a systematic optimization process utilizing Response Surface Methodology (RSM), the effects of solvent type, PS concentration, and titanium dioxide (TiO₂) loading on membrane performance were explored. The fabricated PS polymeric membranes were evaluated for their effectiveness in humic acid removal using a dead-end membrane filtration system. The optimal PS polymeric membrane formula, achieved at PS concentration of 16.31 wt% and TiO₂ concentration of 0.10 g/L using NMP as the solvent, exhibited a permeate flux of 166.55 L/m² h and HA rejected of 84 %. The study also demonstrates the suitability of RSM as a statistical tool for membrane formulation optimization, with low percentage errors (5.04 % for permeate flux and 0.69 % for HA rejection). Furthermore, fouling mechanism analysis utilizing the Hermia’s model confirmed the prevalence of cake filtration in the optimized PS polymeric membrane filtration. This study contributes to the advancement of sustainable membrane technology for wastewater treatment, offering insights into the potential of waste plastic reutilization in membrane fabrication and addressing critical environmental and water resource challenges.