Atık plastiklerden sülfolama ile flokülant sentezi ve plastik yıkama atıksuyu arıtımında etkinliğinin belirlenmesi

The continuous rising of plastic demand led to the growth in waste accumulation in the environment every year. Only 2% of all plastics are closed-loop recycled although with technological advancements in industry all types of polymers can be recycled. Sulfonation is one of the most common methods to modify the surface properties of polymers in order to achieve certain characteristics of desired water absorption, biocompatibility, ion exchange capacity, swelling, etc. In plastics recycling industry the collected waste plastic has been cut into smaller pieces, and then the stock usually needs to be washed in order to remove lingering dirt or attachments. The washing effluent that is produced in washing process is collected as wastewater. The main pollutant parameters in such wastewaters are chemical oxygen demand (COD), suspended solids and high pH. Thus, the washing water needs to be purified prior to discharge. In this study first several polymeric flocculants were synthesized with waste polystyrene (PS) and waste PET by modifying the conventional PS sulfonation process. The synthesized materials were characterized and sulfonation was confirmed. Then the effectiveness of those synthesized materials in coagulation/flocculation treatment of plastic washing wastewaters in terms of turbidity, COD, and TSS removals were investigated. Synthesized flocculants have higher performance under the same conditions as their conventional counterparts, PEL. The highest turbidity removal (86%) was obtained at original pH with a dose of 50 mg.L-1 FSPET2 flocculant in HDPE WPWW and the highest COD (79%) and TSS (52%) removals were achieved in PS and PET WPWWs. PS and HDPE WPWWs treatment performances were high at the original pH, whereas LDPE and PP wastewaters had the best treatment at pH 7, PET and mixed plastic wastewater had high treatment at pH 9. Keywords: Coagulation/Flocculation; Polymeric flocculant; Sulfonation; Waste plastic washing wastewater (WPWW)