What can be used to neutralize the charge of colloidal particles?

Coagulants are used to neutralize the charge of colloidal particles in wastewater treatment processes. Colloidal particles often possess a negative charge, which prevents them from aggregating and settling out of the solution. Coagulation involves the addition of chemical agents, such as aluminum sulfate or ferric chloride, which carry a positive charge. When these coagulants are introduced to the colloidal suspension, they neutralize the negative charges on the colloidal particles. This neutralization allows the particles to come together and form larger aggregates, or flocs, which can then be removed from the wastewater through sedimentation or filtration.

By effectively reducing the charge on colloidal particles, coagulants play a crucial role in improving the efficiency of wastewater treatment processes, thereby enhancing water quality before it is discharged or further treated.