Water, Air, Energy, And Waste Management For Environmental Sustainability Practice Test

Coagulation and flocculation focus on removing particles that are too small to settle on their own by first neutralizing their surface charges and then growing them into larger aggregates. A coagulant neutralizes the negative charges on colloids, allowing them to come together instead of repelling each other. Gentle mixing then promotes collisions and growth into larger flocs that can settle in a clarifier or be removed by downstream filtration. This step improves water clarity, lowers turbidity, and reduces the load on filters and disinfection downstream. Removing dissolved salts requires processes like ion exchange or desalination, sterilizing by high heat is a disinfection method, and pathogens are not removed exclusively by filtration—coagulation targets suspended solids and colloids, enabling their removal.