State-of-the-art recovery of phosphorus from wastewater

Since there can be no life without phosphorus and the limited resources of phosphorus are concentrated in only a few countries, it is important that all efforts be made to recover and re-use phosphorus. Discharge to rivers and oceans leads to an unsustainable consumption of phosphorus. This resulted in concerns in some countries like Sweden and the Netherlands where goals have been set for phosphorus recovery from used water plants and from agricultural runoff. The increase in incineration of residuals in these countries has led to extensive research into methods to extract phosphorus from residuals by physical-chemical means. There is a renewed interest in biological phosphorus removal of phosphorus which would allow the recovery of at least 40% of the phosphorus in the influent stream in a cost effective way, even when the sludge is incinerated. This paper looks at the processes that have been developed and their state of application.