Which method is primarily used to remove inorganic phosphorus in wastewater treatment?

Chemical precipitation is the principal method used to remove inorganic phosphorus from wastewater. This process involves adding certain chemicals, like metallic salts (often alum or ferric chloride), to the wastewater. These chemicals react with the dissolved phosphorus, causing it to form solid precipitates that can then be easily removed from the water through sedimentation or filtration.

This method is particularly effective for inorganic phosphorus, which is commonly present in wastewater due to various sources, including detergents, human waste, and agricultural runoff. By using chemical precipitation, treatment facilities can significantly reduce the concentration of phosphorus in the effluent, helping to prevent eutrophication in receiving water bodies, which can lead to harmful algal blooms and other ecological issues.

While other treatments, such as biological assimilation, can also reduce phosphorus levels, they are more effective for organic forms of phosphorus and often take longer to achieve results compared to the rapid action of chemical precipitation. Filtration primarily removes suspended solids rather than targeting phosphorus specifically, and the activated sludge process is more focused on the removal of organic materials and nutrients in a biological context.