Thermal-alkaline solubilization of waste activated sludge as a pre-treatment stage for anaerobic digestion.
This work studied the hydrolysis kinetics and the solubilization of waste activated sludge under a medium range temperature (50-90 degrees C) and pH in the alkaline region (8-11), as a pretreatment stage for anaerobic digestion. The hydrolysis rate for the solubilization of volatile suspended solids (VSS) followed a first-order rate. A linear polynomial hydrolysis model was derived from the experimental results leading to a satisfactory correlation between the hydrolysis rate coefficient, pH, and temperature. At pH 11 and a temperature of 90 degrees C the concentration of the VSS was 6.82%, the VSS reduction reached 45% within ten hours and at the same time the soluble COD was 70.000 mg/l and the total efficiency for methane production 0.28 l of CH4 per g of VSS loading.
Laboratory of Organic and Chemical Technology, Department of Chemical Engineering, National Technical University of Athens, 9 Heroon Polytechniou Strasse, Zographou, 157 00 Athens, Greece.
A G
AG
Vlyssides
P K
PK
Karlis
D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D006115:Greece; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008697:Methane / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D012722:Sewage / Q000032:analysis*; D012995:Solubility; D013696:Temperature
D012722:Sewage; D008697:Methane; D010100:Oxygen