Removal of Colloidal Suspension through Coagulation – Flocculation Process In Water Purification – A Review

Abstract

In water treatment, the most challenging problem that environmental engineers encounter is the separation and settling of colloids from water. Objective: The study aims to present various aspects of coagulation-flocculation in the removal of colloidal impurities from water. The shape, size, and significant characteristics of colloidal particles have been discussed in the present study. The colloidal systems, origin and nature of charge on colloids, and the stability theories including the concept of zeta potential have also been explained. The study has also been extended for conventional coagulants along with natural coagulants. The effectiveness of various coagulants has been extensively reviewed and presented herein. The review indicates that natural coagulants are equally effective as conventional salt-based coagulants. Conclusion: It is concluded from the present study that polymer-based coagulants are more effective than conventional coagulants. The removal of colloidal impurities from water is an important aspect. The separation of colloidal impurities by coagulation and flocculation is an effective method of water treatment that is safe and sustainable.