Biogas Production from Excess Sludge Oxidized with Peracetic Acid (PAA)

Human functioning related to living and economic activity involves generating an increasing amount of sewage and sludge, which needs to be subjected to advanced processes of treatment, neutralization, and management. The deterioration in the susceptibility of excess sludge to biochemical decomposition observed under anaerobic conditions leads to the development and application of highly effective methods of wastewater treatment based on the removal of biogenic compounds using activated sludge, with a high degree of sludge thickening obtained in mechanical facilities. The concentration of volatile fatty acids, being an important intermediate product of anaerobic stabilization, directly determines biogas production efficiency. This study aimed to determine the effect of chemical disintegration with peracetic acid on biogas production efficiency using methane fermentation of pretreated sludge. Intensification of the hydrolysis phase is an important determinant of the efficiency of biochemical sludge decomposition under anaerobic conditions. The association of excess sludge oxidation, initiated by peracetic acid with biological hydrolysis, which is the first phase of methane fermentation, led to an increase in sludge digestion degree and biogas production efficiency. The compound of STERIDIAL W-10, which is an aqueous solution of 10% peracetic acid, 10% acetic acid, and 8% hydrogen peroxide, was used. The disintegration of excess sludge with a reactant dose of 3.0 mL of STERIDIAL W-10/L yielded a specific biogas production of 0.52 L/g VSS and a 74% degree of sludge digestion.