Utilization of chitosan as a natural coagulant for polyethylene microplastic removal

The widespread use of plastic has led to environmental pollution and health issues due to its persistence and the formation of microplastics—particles smaller than 5 mm that arise from the breakdown of larger plastics. These microplastics pose significant environmental threats, especially in aquatic ecosystems, where they act as carriers for pollutants. Various treatment methods, including coagulation, have been explored to mitigate microplastic pollution. Among coagulants, chitosan—a natural polysaccharide derived from chitin—has shown promise due to its effectiveness and environmental compatibility. This study investigates the use of chitosan to remove polyethylene microplastics in synthetic wastewater, focusing on the effects of pH and coagulant dose. The results indicate that the highest coagulation efficiency, achieving an 81.5 % removal, occurs at a pH of 6.0 with a chitosan dose of 100 mg/L via charge neutralization as the primary coagulation mechanism. These findings emphasize chitosan's potential as an environmentally friendly approach to mitigating microplastic pollution in water treatment.