What is commonly used as a coagulant in water treatment?

Alum, or aluminum sulfate, is widely utilized as a coagulant in water treatment processes. It works by neutralizing the charges of suspended particles in water, allowing them to clump together and form larger aggregates known as flocs. This aggregation enhances the removal of particles from water during the sedimentation process, leading to clearer and safer water.

The use of alum is particularly effective in various types of water treatment systems, as it can significantly reduce turbidity and help in the removal of pathogens and organic material. Its application in both drinking water and wastewater treatment makes it a cornerstone in ensuring water quality and safety.

While lime is used to adjust pH and can aid in coagulation, it is not primarily classified as a coagulant. Chlorine and ozone are oxidants predominantly employed for disinfection rather than coagulation, as their primary function is to kill bacteria and other pathogens. Thus, alum stands out distinctly as the recognized coagulant used specifically for the purpose of enhancing particle removal in water treatment.