Inverted Phase Fermentation and ultrasound pre-treatments of sewage sludge: Biochemical methane potentials

Ultrasound disruption and Inverted Phase Fermentation -IPF- (enzymatic hydrolysis) were applied to sewage sludge. IPF is a novel technique for sludge thickening resulting in a clarified phase ("Liquid Phase" -LP-) beneath a thickened fraction ("Solid Phase" -SP-). An increased hydrolysis rate is obtained in both phases. Biochemical Methane Potentials after applying these pre-treatments were compared: 0.054 LCH4/ gVSo for untreated sludge, 0.065 LCH4/gVSo for sludge pre-treated with ultrasound at 7,500 kJ/kgTS, 0.226 LCH4/gVSo for the SP, and 0.264 LCH4/gVSo for the LP. Sludge pre-treated with ultrasound at 15,000 kJ/kgTS did not achieve the level of methane production untreated sludge did. © 2013 DEStech Publications, Inc.