| Background: Landfills are the most important producers of methane as human source. So, prediction of landfill gas generation is by far the most important concern of scientists, decision makers, and landfill owners as well as health authorities. Almost all the currently used models are based on Monod equation first order decay rate which is experimental while the main purpose of this research is to develop a numerical model. Methods: A real scale pilot landfill with 4500 tons of municipal solid waste has been designed, constructed, and operated for two years. Required measurements have been done to provide proper data on greenhouse gases emitted by the landfill and monitor its status such as internal temperature, leachate content, and its settlement during two years. Afterwards, weighted residual method has been used to develop the numerical model. Then, the newly mathematical method has been verified with data from another landfill. Results: Measurements showed that the minimum and maximum percentages of methane among landfill gas were 22.3 and 46.1%, respectively. These values for velocity of landfill gas are 0.3 and 0.48 meters per second, in that order. Conclusion: Since there is just 0.6 percent error in calculation as compared to real measurements from a landfill in California and most of the models used have ten percent error, this simple empirical numerical model is suggested to be utilized by scientists, decision makers, and landfill owners. |
- References
- Mackie KR, Cooper CD. Gas emission prediction using Voronoi diagrams and importance sampling. Environmental Modelling & Software 2009; 24: 1223-32.
- Yen-Cho C, Chenb K, Wu CH. Numerical simulation of gas flow around a passive vent in a sanitary landfill. J Hazard Mater 2003; 100: 39-52.
- Papageorgiou A, Barton JR, Karagiannidis A. Assessment of the greenhouse effect impact of technologies used for energy recovery from municipal waste: A case for England. J Environ Manage 2009; 90: 2999â3012.
- Shariatmadari N, Sabour M, Kamalan H, Mansouri A, Ablofazlzade. Appling Simple Numerical Model to Predict Methane Emission from Landfill. Journal of Applied Science 2007; 7: 1511-15.
- Sabour M, Kamalan H. Prediction of Methane Emission from the First Sanitary Cellule in Iran. 8th International Congress in Civil Engineering, Shiraz. 2009; 8: 16.
- Manna L , Zanetti MC, Genon G. Modeling biogas production at landfill site. Resources, Conservation and Recycling 1999; 26: 1â14.
- Kamalan H: Modeling of Greenhouse Gases Emission out of Urban Solid Waste Landfills in Arid and Semi- Arid Region (Case Study: Tehran). Ph.D. Thesis, K.N. Toosi University of Technology, Iran. 2009.
- Ozkaya B, Demir A, Bilgili MS. Neural network prediction model for the methane fraction in biogas from field-scale landfill bioreactors. Environmental Modeling & Software 2006; 1: 1-8.
- Mavrotas G, Skoulaxinou S, Gakis N, Katsouros V, Georgopoulou E. A multi-objective programming model for assessment the GHG emissions in MSW management. Waste Manag 2013; 33(9): 1934-49.
- Gardner N, Probert SD. Forecasting landfillgas. Applied Energy, Elsevier Science Publishers Ltd, England. 1999; 4: 131-63. EPA: Inventory of Greenhouse Gas Emissions and Sinks 1990-1997. Office of Policy, Planning, and Evaluation, U.S. Environmental Protection Agency, Washington, DC. 1999. (Available on the Internet at http://www.epa.gov/ globalwarming/inventory/index.html.)
- Kamalan H, Sabour M, Shariatmadari N. A Review on Available Landfill Gas Models. Environ Sci Technol 2011; 4: 79-92.
- Scharff H, Jacobs J. Applying guidance for methane emission estimation for landfills. Waste Manag 2006; 26: 417-29.
- Nojedehi P, Heidari M, Ataei A, Nedaei M, Kurdestani E. Environmental assessment of energy production from landfill gas plants by using Long-range Energy Alternative Planning (LEAP) and IPCC methane estimation methods: A case study of Tehran. Sustainable Energy Technologies and Assessments 2016; 16: 33-42.
- IPCC. IPCC Guidelines for National Greenhouse Gas Inventories: Reference Manual. Chapter 6:waste. 1996.
- Environmental Agency: Gas Sim Lite user manual. release 1. United Kingdom Environmental Agency, UK, 2001 (available on internet at http://www. gassim.co.uk/graphics/documents/GasSimLite_User_ Manualv1.02.pdf)
- Xu F, Li Y, Wang Z. Mathematical modeling of solidstate anaerobic digestion. Prog Energy Combust Sci 2015; 51: 49-66.
- Sobamowo M. Thermal analysis of longitudinal fin with temperature-dependent properties and internal heat generation using Galerkinâs method of weighted residual. Applied Thermal Engineering 2016; 99: 1316-30.
- Afshar H: Finite elements and approximation. Iranian University of Science and Technology. Iran. 2002.
- Jeong S, Lee E. Weighted norm least squares finite element method for Poisson equation in a polyhedral domain. Journal of Computational and Applied Mathematics 2016; 299: 35-49.
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