Recycling Polystyrene Plastic Waste: A Sustainable Solution for Turbidity Removal through Coagulation-Flocculation

The current study chemically recycled polystyrene waste using several methods. Specifically, sulfonated polystyrene PSS-01 was synthesized using the first method, and PSS-02 was synthesized using the second approach. FTIR, UV–visible, XRD, XRF, SEM, and TGA resulted in copolymers with high sulfonation degree, good thermal stability, and smooth and porous surfaces. The ability of the synthesized copolymers to remove turbidity from kaolin suspension was investigated. The highest turbidity removal or faster sedimentation was observed using PSS as a flocculant. The developed flocculant PSS-01 was more effective in the presence of kaolin than PSS-02. At best, by applying 300 mg/L of the solution, the highest turbidity removals of 92 and 78% were obtained by using 4 ppm PSS-01 at pH 6 and 8 ppm PSS-02 at the same pH, respectively. The removal difference was due to the composition and the degree of sulfonation between them. FTIR and XRD analysis proved the presence of the flocculant in the floc structure.