How does the source of waste activated sludge influence the release of phosphorus when treated by thermal hydrolysis?

Abstract

Two sludge samples were subjected to thermal hydrolysis under the same conditions to evaluate P release to the liquid phase. P species were characterised after and before the treatment. Different P release (%) was obtained for both samples, leading to the formulation of 2 hypotheses which are currently under investigation: the release kinetics of polyphosphates during thermal hydrolysis treatment and the different polyphosphate structures in the two samples.