Critical Reviews in Environmental Science and Technology vol:45 issue:4 pages:336-384
Phosphorus is an essential element for all life on earth. However, natural phosphorus resources (phosphate rock) are depleting. This paper describes the current situation and a forecast for future phosphate production and reserves. The current depletion of phosphate reserves and the increasingly stringent discharge regulations have led to the development of various phosphorus (P) recovery techniques from wastewater. Existing full-scale P-recovery techniques from the liquid phase, from the sludge phase and from sludge ash are reviewed. Although the full-scale P-recovery techniques have been shown to be technologically feasible, the economical feasibility, legislation and national policies are the major reasons why these techniques are not yet operational worldwide.