Phosphorus Release and Thermal Hydrolysis Pretreatment Effects on the Dewatering Properties of a Bio-P Biosolid in Anaerobic Digestion

The use of biological phosphorus removal by activated sludge has been shown to have adverse effects downstream in the solids handling processes of anaerobic digestion. From struvite formation problems within the digesters to increased polymer dosage and dewatered biosolids solids content. The fundamental cause is unknown however phosphorus removal prior to anaerobic digestion has been shown to improve cake solids. Thermal hydrolysis pretreatment has also been shown to increase cake dewaterability. This study employed both strategies and has shown that while phosphorus release did not improve cake dewaterability thermal hydrolysis pretreatment has.