Enhancing biomethanation from dairy waste activated biomass using a novel EGTA mediated microwave disintegration.

A novel approach to explore the impact of calcium specific chelant - Ethylene glycol tetra acetic acid (EGTA) on deflocculation followed by biomass disintegration using microwave (MW) was investigated. In the first phase of the study, the EGTA dosage of 0.012 g/g suspended solids (SS) was found to be optimal for disassociating the biomass. Subsequent disintegration of biomass in microwave (EGTA-MW) yielded a biomass lysis and solids reduction of about 39.7% and 30.5%. EGTA-MW disintegration reduces the amount of specific energy required to disintegrate the biomass from 18,900 kJ/kg TS to 13,500 kJ/kg TS, when compared to control. The impact of EGTA-MW disintegration on anaerobic digestion was also evident from its methane yield (235.3 mL/g VS) which was 36.2% higher than control. An economic assessment of this study provides a net profit of 8.48 €/ton in EGTA-MW and highly endorsed for biomass disintegration.

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

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.