1. Coagulants and Flocculants Coagulation and flocculation are essential processes in the primary treatments of wastewater. Coagulants, such as aluminum sulfate and ferric chloride, are used to destabilize colloidal particles, facilitating their aggregation into larger particles or flocs. This process aids in solid-liquid separation, allowing for the effective removal of suspended solids. Flocculants, often synthetic polymers, are used to promote the agglomeration of these flocs, enhancing their settleability.