Chemical Phosphorus Removal: All You Need to Know about Which One to Choose and Where and How Much to Add?

With increasingly stringent effluent phosphorus requirements, the use of chemical phosphorus removal has increased. Chemical phosphorus removal in wastewater treatment has been used both as an independent/conventional process instead of biological phosphorus removal system and is nearly always included in tertiary effluent polishing to meet more stringent regulations. This interactive session at WEFTEC 2023 includes various chemicals typically used in wastewater treatment for phosphorus removal, mechanisms in chemical phosphorus removal, specifically for aluminum-based and iron-based chemical salts, dosage and mixing requirements for optimum phosphorus removal, and solids production due to chemical addition for phosphorus removal. In an interactive section, the attendees will calculate chemical dose requirements for aluminum-based and iron-based chemicals to achieve various levels of effluent phosphorus concentrations, e.g. 1 mg P/L or 0.1 mg P/L, identify the impacts of mixing on dose requirements, and estimate the sludge production. A fact sheet is scheduled for publication by the Water Environment Federation (WEF) in 2023. This interactive session is based on the work of the Chemical Phosphorus Removal, a subgroup for Phosphorus Removal Design Group, a subcommittee formed under Municipal Resource Recovery Design Committee (MRRDC) of Water Environment Federation (WEF). The goal of the Chemical Phosphorus Removal subgroup is to summarize the current knowledge in the fundamentals and provide design criteria for chemical phosphorus removal processes.