What does the process of coagulation involve in water treatment?

The process of coagulation in water treatment specifically involves adding chemicals that facilitate the clumping together of fine particles and impurities suspended in water. This is a critical step in the water purification process, as it helps to improve the clarity and quality of the water by aggregating small particles into larger ones, known as flocs. These larger flocs can then be more easily removed from the water during subsequent processes such as sedimentation and filtration.

In coagulation, chemicals like alum or ferric chloride are commonly used. When these coagulants are added to water, they neutralize the charges on the particles, allowing them to stick together and form larger clusters. This enhances the efficiency of downstream processes and helps reduce the amount of contaminants in the final treated water.

The other choices focus on different processes not directly related to coagulation. For instance, while adding chemicals for chemical reactions can occur in water treatment, it does not specifically describe the coagulation function of aiding particle clumping. Filtering out waste materials pertains to the physical separation processes rather than the chemical interaction that characterizes coagulation. Lastly, heating water to kill pathogens is a disinfection method rather than a coagulation process.