Coagulation-Sedimentation Optimization for Turbidity and Natural Organic Matter Removal in Surface Water Treatment

Abstract

Surface water used for drinking water supply often contains high levels of turbidity and natural organic matter, which adversely affect water quality, treatment efficiency, and disinfection performance. The present study investigates the optimization of coagulation–sedimentation processes for effective removal of turbidity and natural organic matter from surface water under varying operational conditions. Experimental analysis was conducted to evaluate the influence of coagulant dosage, pH, mixing intensity, sedimentation time, and raw water characteristics on treatment performance and floc formation behavior. Results demonstrate that optimized coagulation conditions significantly enhance particle destabilization and aggregation, leading to improved sedimentation efficiency and substantial reduction in suspended solids and dissolved organic compounds. The study further reveals that proper control of rapid mixing and flocculation parameters promotes the formation of larger and denser flocs, thereby improving settling characteristics and reducing residual turbidity in treated water. Natural organic matter removal was observed to increase with appropriate coagulant selection and pH adjustment, contributing to lower disinfection byproduct precursor concentrations and improved water safety. Comparative assessment with non-optimized treatment conditions confirms that process optimization reduces chemical consumption, enhances operational stability, and improves overall treatment efficiency.