Chemicals for Phosphorus Removal

Chemical phosphorus removal helps achieve very low levels of effluent phosphorus, either individually or in combination with biological phosphorus removal. Some typical chemicals used for phosphorus removal include iron and aluminum salts, lime, and earth metals. Most chemicals used for phosphorus removal consume alkalinity and depress pH, except for chemicals such as sodium aluminate or lime, which increase alkalinity and pH. Bench-, pilot-, and field-scale studies have been conducted on various metal salts for the past several decades, providing guidance for the optimization of chemical phosphorus removal processes. This fact sheet includes summaries of key considerations for chemical addition to achieve efficient chemical phosphorus removal.