Chemically coupled microwave and ultrasonic pre-hydrolysis of pulp and paper mill waste-activated sludge: effect on sludge solubilisation and anaerobic digestion.

The effects of alkali-enhanced microwave (MW; 50-175 °C) and ultrasonic (US) (0.75 W/mL, 15-60 min) pretreatments, on solubilisation and subsequent anaerobic digestion efficiency of pulp and paper mill waste-activated sludge, were investigated. Improvements in total chemical oxygen demand and volatile suspended solids (VSS) solubilisation were limited to 33… (More)