What does coagulation refer to in water treatment?

Coagulation in water treatment refers to the process where chemicals, known as coagulating agents, are added to water to neutralize the charges of colloidal particles. These colloids, which are tiny, suspended particles in the water, can be negatively charged and remain dispersed, creating a stable suspension. When coagulating agents are introduced, they cause these particles to clump together or coagulate, forming larger aggregates called flocs. This process is crucial because it helps to remove suspended solids and impurities from the water, making it easier to separate from the clear water through subsequent filtration processes.

The effectiveness of coagulation is essential in preparing water for further treatment steps, such as sedimentation and filtration, ultimately leading to cleaner drinking water.