Comparative evaluation of sedimentation and pulsator clarifier systems using aluminium sulphate coagulant in water treatment

Abstract

In Sri Lanka, surface water is the main source for the urban drinking water supply system. Surface water bodies are recharged during the rainy season to supply the required amount of water for drinking and agricultural use. However, the use of surface water introduces several key challenges for engineers and scientists, including variable water quality, high turbidity, and the presence of natural organic matter and emerging contaminants. Coagulation is widely used worldwide to remove mainly colloidal and suspended particles. (Maldhure et al., 2021). In water treatment plants (WTPs), the coagulant plays a crucial role in neutralizing the electrostatic repulsive forces of these particles. The coagulant’s metal ion attracts these negatively charged particles and coagulates with them to form small-sized floc (Maldhure et al., 2021). Mainly, aluminum-based coagulants, such as alum and poly-aluminum chloride, are widely used in Sri Lanka.