prechlorination

Prechlorination is the process of adding chlorine to water before filtration in water treatment. The primary goal of water treatment is to ensure the safety and aesthetic quality of drinking water, protecting public health by removing harmful microorganisms and chemicals. While groundwater often requires less treatment, surface water from rivers and lakes typically needs more extensive purification due to natural contaminants like silt, organic matter, and microbes.12

Common treatment methods include clarification to remove turbidity and disinfection to kill pathogens. Chlorination, using chlorine gas or compounds, is a widely used disinfection method. It helps eliminate taste and odor issues and maintains a safe residual level in the distribution system. However, chlorine can react with organic matter to form by-products like chloroform, a risk minimized when chlorine is applied after other treatment stages.2