What is the primary role of coagulants in water treatment?

The primary role of coagulants in water treatment is to create larger particles from smaller ones. In the water treatment process, coagulants are chemicals that induce coagulation, which is the process of aggregating small particles such as silt, clay, and organic matter into larger clusters known as flocs. This aggregation occurs due to the neutralization of charges on the particles, allowing them to come together and form larger masses that can be more easily removed from the water during subsequent filtration.

This process is crucial in improving water clarity and quality, as it helps in effectively removing suspended solids and contaminants, leading to cleaner and safer drinking water. The formation of flocs allows for better settling during sedimentation or more efficient capture during filtration.

In this context, the other options do not accurately reflect the primary function of coagulants. While purifying water is a broader goal of water treatment, it does not specifically describe the action of coagulants. Speeding up water flow and reducing water temperature are not related to the coagulation process at all. Therefore, the focus on the creation of larger particles succinctly captures the essential role that coagulants play in the treatment of water.