Process Optimization of Waste Activated Sludge in Anaerobic Digestion and Biogas Production by Electrochemical Pre-Treatment Using Ruthenium Oxide Coated Titanium Electrodes

Anaerobic digestion (AD) appears to be a popular unit operation in wastewater treatment plant treat waste activated sludge (WAS) and the produced methane gas can harvested as renewable energy. However, WAS could inhibit hydrolysis stage during AD hence pre-treatment is required overcome issue. This paper aimed study effect of electrochemical (EP) towards efficiency using titanium coated with ruthenium oxide (Ti/RuO2) electrodes. The investigation has been carried out in-house laboratory batch-scale mesophilic anaerobic digester, mixed under manipulation important operating parameters. Optimization was performed on EP response surface methodology central composite design maximize disintegration dewaterability. By at optimal conditions (pH 11.65, total solids 22,000 mg/L, electrolysis time 35 min, current density 6 mA/cm2, 1000 mg/L sodium chloride), pre-treated terms liquor volatile suspended (MLVSS) removal, soluble chemical oxygen demand (sCOD), capillary suction (CST) reduction, extracellular polymeric substance (EPS) were 38%, 4800 (increased from 935 mg/L), 33%, 218 respectively. Following AD, (VS) removal (COD) by enhanced 40.7% 54.7% 47.2% 61.5%, respectively, steady-state. biogas control ranges 0.12 0.17 0.2 0.24 m3/kg VSfed, volume 44–67% over control. Based results obtained, suitability for prior confirmed.