Which substance is widely used as a coagulant in water treatment processes?

Aluminum sulfate is widely used as a coagulant in water treatment processes due to its effectiveness in promoting the aggregation of suspended particles, making them easier to remove during filtration. When added to water, aluminum sulfate dissolves and reacts with alkalinity to form aluminum hydroxide, which acts as a flocculating agent. This process aids the removal of impurities, including turbidity, microorganisms, and organic matter, by creating larger clusters (or flocs) that can settle more easily during sedimentation.

The choice of aluminum sulfate for coagulation is well established in both municipal and industrial water treatment settings, making it a standard practice due to its reliable performance and cost-effectiveness. Its ease of use, alongside its ability to function across a range of pH levels, further enhances its suitability as a coagulant, solidifying its role in effectively treating water supplies.