Chemical treatment is typically employed after primary physical treatment methods. It involves various processes such as coagulation, flocculation, sedimentation, and disinfection. Coagulation is the initial stage, where chemicals known as coagulants (commonly aluminum sulfate or ferric chloride) are added to wastewater. These coagulants destabilize suspended particles, allowing them to clump together, forming larger aggregates known as flocs.
1. Coagulation This chemical process involves adding coagulants, such as aluminum sulfate or ferric chloride, to the water. These substances neutralize the negative charges of particles, allowing them to clump together into larger aggregates, which can then be easily removed through sedimentation or filtration.