Sustainable Solvent-Based Extraction of Polymers from Plastic Waste for Antibacterial Water Purification Membranes

The escalating volume of plastic waste in metropolitan regions poses a significant environmental and ecological threat, mainly due to the complexity of mixed polymer compositions that hinder effective sorting and recycling. This study addresses this challenge by manually sorting post-consumer plastic waste and recovering polyethylene (PE), polypropylene (PP), and polystyrene (PS) using a solvent-based dissolution-precipitation (SDP) method. The extracted polymers are characterized through NIR spectroscopy, XRD, SEM, EDX, and thermogravimetric analysis (TGA) to confirm their purity and thermal stability. Recycled polymers are then fabricated into membranes and assessed for antibacterial performance against Escherichia coli. Among the samples, PS membranes exhibit the most potent antibacterial activity, reducing E. coli colony growth with a distinct and measurable inhibition zone (17 ± 0.76 mm), which is further amplified in the presence of antibiotics (25 ± 1.52 mm). This research highlights a promising pathway for converting plastic waste into high-value, antibacterial membranes for potential applications, such as water purification, which contributes to circular economy goals and environmental sustainability.