Chemical treatment is a treatment process carried out in wastewater or water treatment plants by using various chemical substances to clean the water. This process consists of stages such as precipitation of pollutants in water, flocculation, neutralisation and disinfection.
Coagulation
Coagulation is a chemical treatment step that allows the colloidal particles in wastewater to come together. In this step, some coagulants are added to the water. These coagulants attract and bind negatively charged particles in the water together to form large, settleable particles. These large particles can then be separated in settling tanks or other units.
Neutralisation
Neutralisation is a chemical treatment step that regulates the acidic or basic properties of wastewater. In this process, the pH level is adjusted by adding acid or base. Neutralisation is important to reduce environmental impacts and optimise biological treatment processes.
Flocculation
Flocculation is a process that allows further coalescence of large particles formed in the coagulation stage. At this stage, some chemicals are added to the water. These chemicals increase the interaction between the particles, resulting in the formation of larger flocs. These larger flocks are settled more effectively in settling tanks.
Chemical Precipitation
Chemical precipitation is a chemical treatment step that allows the precipitation of the fluxes formed in the previous steps. In this step, precipitates of substances dissolved in water are formed by adding various chemicals. The precipitates are deposited in settling tanks and can be removed later.
Disinfection
At the end of the treatment process, the water is disinfected to remove microorganisms. This is usually achieved through the use of chlorine, ozone, ultraviolet (UV) rays or other disinfectant agents.