Phosphorus Removal and Recovery from Municipal Wastewaters

Phosphorus is a key pollutant in municipal wastewater. To minimise eutrophication, treatment facilities must often reduce phosphorus levels to less than 1 mg L-1. Two main approaches to achieving this are chemical precipitation and enhanced biological uptake. Chemical precipitation is widely used and relatively simple; biological phosphorus removal is more complex but relies less on the addition of chemicals and also offers the opportunity to reuse the phosphorus. Phosphorus can be released from cells and converted to calcium phosphate or the mineral struvite. While the products have been shown to be excellent fertilisers, the economic drivers for recovery are still not clear.