H2O2 induced cost effective microwave disintegration of dairy waste activated sludge in acidic environment for efficient biomethane generation

[Display omitted] •EPS dissociation was enhanced by the addition of 0.5mg/g SS of H2O2 in acidic pH.•HAMW-D process liquefies organics at 10,810kJ/kg TS of specific energy input.•The novel HAMW-D process improves methane production (250mL/g VS) efficiently.•Cost analysis indicated that HAMW-D process was economically feasible than MW-D. This study aimed to improve the biomethane potential of dairy waste activated sludge (WAS) by H2O2-acidic pH induced microwave disintegration (HAMW-D) pretreatment approach. The results of HAMW-D compared with the microwave disintegration (MW-D) alone for energy and economic factors. In the two phase disintegration process, the H2O2 concentration of about 0.5mg/g SS under acid pH of 5 was found to be optimum for effective dissociation of Extracellular Polymeric Substances (EPS) matrix. A higher liquefaction of about 46.6% was achieved in HAMW-D when compared to that of MW-D (30%). It subsequently improved the methane yield of about 250mL/g VS in HAMW-D, which was 9.6% higher than MW-D. A net profit of about 49€/ton was achieved for HAMW-D, therefore it is highly recommended for WAS pretreatment.