Abstract:
This study focused on finding removal efficiency of 103 to 300 μm microplastics (MPs) via coagulation and flocculation process. Water samples were collected from Khlong Prapa, Don Mueang, Bangkok, Thailand. Total hardness, total alkalinity, pH, turbidity, and conductivity in raw water were 115.72 mg/L as CaCO₃, 104.29 mg/L as CaCO₃, 7.4 to 8.2, 20.40 to 32 NTU, and 352 to 565 μS/cm respectively. 20 MPs particles with organic matters on surface from immersing in sugar factory wastewater were then added in raw water to obtain optimum doses of alum and APAM for coagulation and flocculation processes. The results showed that alum and APAM affected in slightly decrease of pH and slightly increase of conductivity. The maximum turbidity removal efficiency by adding alum alone and adding alum with APAM were 97.87±0.03% and 98.25±0.04%, respectively. In addition, the 103 to 300 μm MPs removal efficiency by adding 37 ppm alum was 85.00±0.00% whereas the removal efficiency by adding 37 ppm alum with 0.04 ppm APAM was more than 90.00±0.00%.