Dive into the 2025 NY Wastewater Exam – Flush Away the Competition with Confidence!

The term used for a chemical that causes fine particles to aggregate into larger particles is "coagulant." Coagulants are commonly employed in water treatment processes to facilitate the removal of suspended solids, contaminants, and impurities. When coagulants are added to a colloidal solution, they neutralize the charges on fine particles, promoting their aggregation. This results in the formation of larger particles or flocs that can be more easily separated from the liquid, enhancing the efficiency of subsequent treatment processes such as sedimentation or filtration.

In contrast, emulsifiers are substances that help stabilize mixtures of two immiscible liquids by reducing surface tension. Flocculants are similar to coagulants but generally work on already aggregated particles to promote further settling. Dispersion agents serve to keep fine particles suspended in a liquid, preventing them from aggregating. Therefore, coagulants specifically target the aggregation process, distinguishing them from the other options listed.