Effect of high salt concentration on phosphorus recovery from sewage sludge and dewatering properties

This paper is a study on the influence of high salinity waters on the dissolved phosphorus content in the liquid phase of waste activated sludge. Next to the dissolution effectiveness as a function of the sodium chloride concentration, the influence of the salt dose on the dewaterability is investigated. It is demonstrated that it is possible to increase the phosphorus content in the liquid phase by high salinity. Furthermore the sludge structure is changed which is beneficial for dewatering processes. In fact, dosing of salt can enhance phosphorus recovery efficiently in cases in which brines or residual salt is available close by wastewater treatment facilities.