Two phase pretreatment on waste activated sludge for efficient bioenergy and value added product retrieval

Abstract

Bioenergy and the valued product such as, polyhydroxybutyrate (PHB) production from waste activated sludge is efficient due to its higher amount of organic content. Owing to the existence of exopolymeric substances (EPS) surrounding the sludge biomass, it restricts the organic release. Thus, pretreatment is obligatory to enhance the biodegradation of sludge. In first segment, the dairy sludge was treated using alkali actuated persulfate for EPS removal followed by bacterial disintegration. The solubilization enhanced to 21% during bacterial pretreatment after EPS removal at 0.015 g /g suspended solids (SS) of sodium persulfate at pH 8. Biohydrogen production potential shows higher hydrogen yield of 103.8 mL/g chemical oxygen demand (COD). newlineIn second segment, the hydrogen peroxide mediated bacterial pretreatment of dairy sludge was done. During bacterial pretreatment, the solubilization of 22% was achieved after the EPS dissociation by adding 8 and#956;L of H2O2 per 100 mL of sludge. Biomethane generation of 174 mL/gCOD was obtained in EPS dissociated and disintegrated biomass. newlineThe PHB producer was isolated from tree bound soil and was identified through 16 s rRNA technique. newline newline