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Technical Papers REFERENCES ABG (2006): Glycerine Market Analysis, Report for US Soy Bean Export Council. Andersons (2008): A Detailed Economic Assessment of Anaerobic Digestion Technology and its Suitability to UK Farming and Waste Systems, prepared for the National Non-food Crops Centre, Defra funded project, NNFCC 08/006, April. Barber WPF (2014): Influence of Wastewater Treatment on Sludge Production and Processing. Water and Environment Journal, 28, 1, pp 1–10. Chen Y, Cheng JJ & Creamer KS (2008): Inhibition of Anaerobic Digestion Process: A Review, Bioresource Technology, 99, pp 4044–4064. Fountoulakis MS, Petousi I & Manios T (2010): Co-Digestion of Sewage Sludge with Glycerol to Boost Biogas Production. Waste Management, 30, 10, pp 1849–1853.
Figure 4. Sankey diagrams showing flow of COD during digestion of sludge and glycerol based on the results of this study. Figure 4a) for 1% addition; Figure 4b) for 2% addition. Key: green = glycerol COD; red = sludge COD. study implies that the benefits of glycerol addition could potentially be greater than observed here. Furthermore, the literature available presents conflicting advice on loading rates possible before failure occurs. Both this study and the literature (Hutňan et al., 2009) highlight the fragility of anaerobic digestion to glycerol overloading, with potential for catastrophic failure. From this study, glycerol is a good candidate as a supplement to anaerobic digestion of sewage sludge when fed at a rate of 2% by volume or approximately 40% by load. However, more work is needed to fully understand the potential of glycerol addition on anaerobic digestion performance.
THE AUTHORS Dr William (Bill) Barber (email Bill.Barber@aecom. com) works on global biosolids projects within AECOM’s Technical Practice Network, and is currently based in Maryland, US. Shona Fitzgerald (email: shona.fitzgerald@ sydneywater.com.au) is a Scientist at Sydney Water with a particular interest in treatment processes and resource recovery.
Marcia Dawson (email: marcia.dawson@sydneywater. com.au) is Strategic Analyst at Sydney Water. She has 10 years’ experience in the water industry, covering best practice planning, demand forecasting, codigestion research and analytics. Sarah Vierboom (email: sarah.vierboom @sydneywater.com.au) is a Senior Technical Specialist in Sydney Water’s Energy and Eco-efficiency team. Her role focuses on driving the organisation’s Energy Efficiency Management Program, assessing energy efficiency and renewable energy opportunities.
ACKNOWLEDGEMENTS The Authors wish to thank a large number of internal and external stakeholders who have contributed to Sydney Water’s Digester Research Program at its various stages. In particular, we would like to acknowledge Long Nghiem and Patrick Manassa from the University of Wollongong and Babu Gomes, Derek Van Rys, Glenn Austin, Tung Nguyen, Tony Williamson, Bondi WWTP production offices, Wayne Jackson, Phil Woods, Brendan Galway and Nicola Nelson from Sydney Water.
Holm-Nielsen JB, Lomborg CJ, OleskowiczPopiel P & Esbensen KH (2008): On-Line Near Infrared Monitoring of GlycerolBoosted Anaerobic Digestion Processes: Evaluation of Process Analytical Technologies. Biotechnology and Bioengineering, 99, 2, pp 302–313. Hutňan M, Kolesárová N, Bodík I, Špalková V & Lazor M (2009): Possibilities of Anaerobic Treatment of Crude Glycerol from Biodiesel Production. Proceedings of the 36th International Conference of the Slovak Society of Chemical Engineering, Paper 156. Lee K, Winter P, Farrow J & Pearce P (2008): Digestibility of Glycerol from Biodiesel Production, 13th European Biosolids & Organic Resources Conference & Workshop, Manchester, UK. Pavlostathis SG & Giraldo-Gomez E (1991): Kinetics of Anaerobic Treatment, Water Science & Technology, 24, 8, pp 35–59. Razaviarani V, Buchanan ID, Malik S & Katalambula H (2013): Pilot Scale Anaerobic Co-Digestion of Municipal Wastewater Sludge with Biodiesel Waste Glycerin. Bioresource Technology, 133, p 206. Viana MB, Freitas AV, Leitão RC & Santaella ST (2011): Anaerobic Biodegradability, Methane Production Potential and Toxicity of the Glycerol Generated on Biodiesel Industry, 10th Latin American Workshop and Symposium on Anaerobic Digestion, Ouro Preto, Brazil. Viana MB, Freitas AV, Leitão RC, Pinto GAS & Santaella ST (2012): Anaerobic Digestion of Crude Glycerol: A Review, Environmental Technology Reviews, 1, 1, pp 81–92. Weng CN & Jeris JS (1976): Biochemical Mechanisms in the Methane Fermentation of Glutamic and Oleic Acids. Water Research, 10, pp 9–18.
DECEMBER 2014 WATER