Impact of ozone assisted ultrasonication pre-treatment on anaerobic digestibility of sewage sludge
Trzcinski, Antoine Prandota
Lin, Li Leonard
Ng, Wun Jern
Date of Issue2015
School of Civil and Environmental Engineering
Nanyang Environment and Water Research Institute
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.
Journal of Environmental Sciences
© 2015 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. This paper was published in Journal of Environmental Sciences and is made available as an electronic reprint (preprint) with permission of The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. The published version is available at: [http://dx.doi.org/10.1016/j.jes.2015.01.003]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.