Contribution of On-Site and Off-Site Processes to Greenhouse Gas (GHG) Emissions by Wastewater Treatment Plants
The estimation of overall on-site and off-site greenhouse gas (GHG) emissions by wastewater treatment plants revealed that in anaerobic and hybrid treatment systems greater emissions result from off-site processes compared to on-site processes. However, in aerobic treatment systems, onsite processes make a higher contribution to the overall GHG emissions. The total GHG emissions were estimated to be 1.6, 3.3 and 3.8 kg CO2-e/kg BOD in the aerobic, anaerobic and hybrid treatment systems, respectively. In the aerobic treatment system without the recovery and use of the generated biogas, the off-site GHG emissions were 0.65 kg CO2-e/kg BOD, accounting for 40.2% of the overall GHG emissions. This value changed to 2.3 and 2.6 kg CO2-e/kg BOD, and accounted for 69.9% and 68.1% of the overall GHG emissions in the anaerobic and hybrid treatment systems, respectively. The increased off-site GHG emissions in the anaerobic and hybrid treatment systems are mainly due to material usage and energy demand in these systems. The anaerobic digester can contribute up to 100%, 55% and 60% of the overall energy needs of plants in the aerobic, anaerobic and hybrid treatment systems, respectively.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1073323Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1692
 M. El-Fadel and M. Massoud, "Methane emissions from wastewater management," Environ. Pollution, vol. 114(2). pp. 177-185, 2001.
 Intergovernmental Panel on Climate Change (IPCC), "Climate change 2001: the scientific basis." Cambridge University Press, Cambridge, U.K. 2001.
 Energy Information Administration (EIA), "Emissions of greenhouse gases report" Report #: DOE/EIA-0573, 2007.
 F.Y. Cakir and M.K. Stenstrom, " Greenhouse gas production: A comparison between aerobic and anaerobic wastewater treatment technology," Wat. Res., vol. 39(17), pp. 4197-4203, 2005.
 P.F. Greenfield and D.J. Batstone, "Anaerobic digestion: Impact of future greenhouse gases mitigation policies on methane generation and usage," Wat. Sci. and Technol., vol. 52(1-2), pp. 39-47, 2005.
 J. Keller, and K. Hartley, "Greenhouse gas production in wastewater treatment: Process selection is the major factor," Wat. Sci. and Technol., vol. 47(12), pp. 43-48. 2003.
 A.K. Mohareb, M. Warith, and R.M. Narbaitz, "Strategies for the municipal solid waste sector to assist Canada in meeting Kyoto Protocol commitments. " Environ. Rev. vol. 12(2), pp. 1-9, 2004.
 H.D. Monteith, H.R. Sahely, H.L. MacLean and D.M. Bagley, "A rational procedure for estimation of greenhouse-gas emissions from municipal wastewater treatment plants," Wat. Environ. Res., vol. 77(4), pp. 390- 403, 2005.
 H.R. Sahely, H.L. MacLean, H.D. Monteith and D.M. Bagley, "Comparison of on-site and upstream greenhouse gas emissions from Canadian municipal wastewater treatment facilities," J. Environ. Eng. and Sci., vol. 5(5), pp. 405-415, 2006.
 M. Bani Shahabadi, L. Yerushalmi, and F. Haghighat, " Development of a Mathematical Model for the Estimation Greenhouse Gas (GHG) Generation in Wastewater Treatment Plants and its Application in the Estimation of GHG Emissions in a Typical Hybrid Treatment System," Submitted to Wat. Res. 2008.
 P.K. Barton and J.W. Atwater, "Nitrous oxide emissions and the anthropogenic nitrogen in wastewater and solid waste." ASCE J. Environ. Eng., vol. 128(2), pp. 137-150, 2002.
 G. Tchobanoglous, F. L. Burton, H. D. Stensel, "Wastewater Engineering: Treatment and Reuse" McGraw-Hill, New York, 2003.
 Z. Xu and G. Nakhla, "Pilot-scale demonstration of pre-fermentation for enhancement of food-processing wastewater biodegradability," J. Chem. Technol. and Biotechnol., vol. 81(4), pp. 580-587, 2006.
 Intergovernmental Panel on Climate Change (IPCC),"Good practice guidance and uncertainty management in national greenhouse gas inventories," Geneva, Switzerland, 2000.
 Canadian Lime Institute. Office of Energy Efficiency, "Energy efficiency opportunity guide in the lime industry," Natural Resources Canada, Ottawa ON, Canada. 2001.
 Y. Dong and M. Steinberg, "Hynol-an economical process for methanol production from biomass and natural gas with reduced CO2 emission," International J. Hydrogen Energy, vol. 22(10-11), pp. 971-977. 1997.