One of the primary categories of chemicals used in wastewater treatment is coagulants. Coagulants are substances that help remove suspended solids from wastewater by neutralizing the charge on these particles, allowing them to aggregate and settle out more easily. Common coagulants include aluminum sulfate (alum), ferric chloride, and polyaluminum chloride. These chemicals facilitate the process known as coagulation-flocculation, where small particles combine to form larger aggregates, or flocs, that can be removed from the water.
Another essential chemical in sewage treatment is alum, or aluminum sulfate. Alum is a coagulant used in the primary treatment phase to facilitate the removal of suspended solids and colloidal particles. By causing these particles to clump together, or coagulate, alum aids in their subsequent removal through sedimentation. This is particularly important in reducing the turbidity of wastewater, thus improving the efficiency of subsequent treatment processes. The addition of alum not only enhances removal rates but also aids in the stabilization of organic matter.
sewage treatment plant chemicals used