This document discusses the processes of coagulation and flocculation, which are important steps in wastewater treatment. Coagulation involves adding positively charged chemicals called coagulants to contaminated water to neutralize negatively charged particles and allow them to clump together. Common coagulants are aluminum-based or iron-based salts. Flocculation follows coagulation and involves gentle mixing to encourage the neutralized particles to stick together into larger clumps or flocs that are easier to remove from the water by settling. Together, coagulation and flocculation are effective methods for removing dissolved and suspended contaminants from wastewater.