title: Impact of ozone assisted ultrasonication pre-treatment on anaerobic digestibility of sewage sludge.
abstract: Impact of ultrasonication (ULS) and ultrasonication-ozonation (ULS-Ozone) pre-treatment on the anaerobic digestibility of sewage sludge was investigated with semi-continuous anaerobic reactors at solid retention time (SRT) of 10 and 20 days. The control, ULS and ULS-Ozone reactors produced 256, 309 and 348 mL biogas/g CODfed and the volatile solid (VS) removals were 35.6%, 38.3% and 42.1%, respectively at SRT of 10 days. At SRT of 20 days, the biogas yields reached 313, 337 and 393 mL biogas/g CODfed and the VS removal rates were 37.3%, 40.9% and 45.3% in the control, ULS and ULS-Ozone reactors, respectively. ULS-Ozone pre-treatment increased the residual organic amount in the digested sludge. These soluble residual organics were found to contain macromolecules with molecular weights (MW) larger than 500 kDa and smaller polymeric products with MW around 19.4 and 7.7 kDa. These compounds were further characterized to be humic acid-like substances with fluorescent spectroscopy analysis.
authors.affiliation: Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141 Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, 639798 Singapore. Electronic address: tian0047@e.ntu.edu.sg.
authors.forename: Xinbo
authors.initials: X
authors.lastname: Tian
authors.affiliation: Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141 Singapore.
authors.forename: Antoine Prandota
authors.initials: AP
authors.lastname: Trzcinski
authors.affiliation: Public Utilities Board, Water Reclamation (Plants) Department, Singapore, 228231 Singapore.
authors.forename: Li Leonard
authors.initials: LL
authors.lastname: Lin
authors.affiliation: Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141 Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, 639798 Singapore. Electronic address: WJNg@ntu.edu.sg.
authors.forename: Wun Jern
authors.initials: WJ
authors.lastname: Ng
mesh_terms: D000641:Ammonia / Q000737:chemistry; D000693:Anaerobiosis; D019149:Bioreactors; D009584:Nitrogen / Q000737:chemistry; D010126:Ozone / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D013997:Time Factors; D014465:Ultrasonics; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical; D010126:Ozone; D000641:Ammonia; D009584:Nitrogen
keywords: Anaerobic digestion; Molecular weight; Ozone; Pre-treatment; Sewage sludge; Ultrasound