Which chemical aids in the coagulation of water contaminants?

The chemical that aids in the coagulation of water contaminants is Polyaluminum Chloride. This compound is a commonly used coagulant in water treatment processes. It works by destabilizing suspended particles in water, allowing them to clump together into larger aggregates that can then be removed more efficiently through sedimentation or filtration.

Polyaluminum Chloride is particularly effective because it provides aluminum ions that interact with waterborne contaminants, facilitating the coagulation process. This is essential for reducing turbidity and improving water clarity, which are vital aspects of water treatment aimed at making water safe for consumption.

While sodium aluminate does have some coagulation properties, it is not as widely used or as effective in municipal water treatment compared to Polyaluminum Chloride. Sodium chloride, primarily known as table salt, does not play a significant role in coagulation. Calcium carbonate mainly acts as a buffering agent and does not directly contribute to the coagulation process. Thus, Polyaluminum Chloride is the most suitable choice for the specific function of aiding in the coagulation of water contaminants.