Role of Cover Systems to Control Methane Migration from Dumpsites
Publication: Journal of Hazardous, Toxic, and Radioactive Waste
Volume 24, Issue 4
Abstract
The emission of landfill gases from dump sites due to anaerobic biodegradation of waste is a matter of increasing public concern as they significantly contribute to global warming. In order to assess the methane emissions from dump sites and to quantify the effects of clay covers and geosynthetic clay liners (GCLs) in reducing them, numerical simulations were conducted. From the simulations, it was noted that clay covers reduced the atmospheric methane flux fourfold and GCLs produced a sixfold reduction in comparison to open dumps. Atmospheric methane fluxes far above the safe limit were observed for the open dumps, which were significantly lower when covers were in place. Development of large pressures owing to reduced migration and continuous methane production were also observed when covers were present. A study of the effect of geotechnical properties of cover and material types suggested that they affect methane emissions significantly. Absolute permeability, porosity, saturation, and van Genuchten properties influenced methane migration to a large extent and hence should be taken into consideration in a cover design.
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Data Availability Statement
All data, models, and code generated or used during the study appear in the published article.
Acknowledgments
The study is part of the research from the Indo-Sri Lanka joint project, DST/INT/SL/P-13/2016 “Characterising landfill gas emissions: Experimental and numerical investigation (CLEAN),” funded by Department of Science and Technology, Govt. of India, which is gratefully acknowledged.
Notation
The following symbols are used in this paper:
- d
- diffusion coefficient;
- g
- gravitational acceleration (m · s−2);
- F
- Darcy flux (kg m2 · s−1);
- k
- intrinsic permeability (m2) = Kμ/ρg where, K = hydraulic conductivity (m · s−1); μ = dynamic viscosity (kg m−1 · s−1); and ρ = density of the fluid (kg m−3);
- kr
- relative permeability;
- M
- mass accumulation term (kg m−3);
- n
- outward unit normal vector;
- P
- total pressure;
- q
- mass flux (kg m−2 · s−1);
- S
- saturation;
- T
- temperature (°C);
- t
- time (s);
- V
- volume (m3);
- X
- mass fraction;
- β
- phase index (subscript);
- Γ
- surface area (m2);
- κ
- mass components (superscript);
- λ
- van Genuchten m;
- τ
- tortuosity; and
- φ
- porosity.
Subscripts and Superscripts
- g
- gas;
- l
- liquid;
- max
- maximum;
- Pcap
- capillary pressure (Pa);
- r
- residual;
- S
- saturation;
- w
- water; and
- 0
- reference value.
References
Barnswell, K. D., and D. F. Dwyer. 2012. “Two-year performance by evapotranspiration covers for municipal solid waste landfills in northwest Ohio.” Waste Manage. (Oxford) 32 (12): 2336–2341. https://doi.org/10.1016/j.wasman.2012.07.014.
Cramer, S. D. 1982. The solubility of methane, carbon dioxide and oxygen in brines from 0 to 300°C. Volume 8706 of Report of investigations/United States Department of the Interior, Bureau of Mines. Washington, DC: U.S. Department of Interior.
Deepagoda, T. C., K. M. Smits, and C. M. Oldenburg. 2016. “Effect of subsurface soil moisture variability and atmospheric conditions on methane gas migration in shallow subsurface.” Int. J. Greenhouse Gas Control 55: 105–117. https://doi.org/10.1016/j.ijggc.2016.10.016.
Feng, S. J., Z. W. Zhu, Z. L. Chen, and H. X. Chen. 2020. “Analytical model for multicomponent landfill gas migration through four-layer landfill biocover with capillary barrier.” Int. J. Geomech. 20 (3): 04020001. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001598.
Garg, A., and G. Achari. 2010. “A comprehensive numerical model simulating gas, heat, and moisture transport in sanitary landfills and methane oxidation in final covers.” Environ. Model. Assess. 15 (5): 397–410. https://doi.org/10.1007/s10666-009-9217-3.
Ghavam-Nasiri, A., and A. El-Zein. 2016. “Effects of defects in geomembranes on reducing desiccation potential of geosynthetics clay liners.” Jpn. Geotech. Soc. Spec. Publ. 2 (70): 2418–2422. https://doi.org/10.3208/jgssp.IGS-27.
Goldsmith, C. D., Jr., J. Chanton, T. Abichou, N. Swan, R. Green, and G. Hater. 2012. “Methane emissions from 20 landfills across the United States using vertical radial plume mapping.” J. Air Waste Manage. Assoc. 62 (2): 183–197. https://doi.org/10.1080/10473289.2011.639480.
Hoornweg, D., and B. P. Tata. 2012. What a waste: A global review of solid waste management. Urban Public Sector Unit, Paper No. 15. Washington, DC: World Bank.
IPCC, C.C. 2001. “The Scientific Basis.” Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge University Press.
Jackson, R. B., A. Down, N. G. Phillips, R. C. Ackley, C. W. Cook, D. L. Plata, and K. Zhao. 2014. “Natural gas pipeline leaks across Washington, DC.” Environ. Sci. Technol. 48 (3): 2051–2058. https://doi.org/10.1021/es404474x.
Koerner, R. M., and D. E. Daniel. 1997. Final covers for solid waste landfills and abandoned dumps. Reston, VA: ASCE.
Lay, J. J., Y. Y. Li, and T. Noike. 1998. “Mathematical model for methane production from landfill bioreactor.” J. Environ. Eng. 124 (8): 730–736. https://doi.org/10.1061/(ASCE)0733-9372(1998)124:8(730).
Leij, F. J., W. J. Alves, M. T. van Genuchten, and J. R. Williams. 1996. The UNSODA unsaturated soil hydraulic database, (user’s manual 1.0). EPA Report No. 600/R95/095. Washington, DC: USEPA.
Mualem, Y. 1976. “A New Model for Predicting the Hydraulic Conductivity of Unsaturated Porous Media.” Water Resour. Res. 12 (3): 513–522. https://doi.org/10.1029/WR012i003p00513.
Metcalfe, D. E., and G. J. Farquhar. 1987. “Modeling gas migration through unsaturated soils from waste disposal sites.” Water Air Soil Pollut. 32 (1–2): 247–259. https://doi.org/10.1007/BF00227697.
Millington, R. J., and J. P. Quirk. 1961. “Permeability of porous solids.” Trans. Faraday Soc., 57: 1200–1207.
Minnesota Pollution Control Agency. 2011. Guidelines for monitoring for landfill gas at and near former dumps. Saint Paul, MN: Minnesota Pollution Control Agency.
Mohsen, M. F. N., G. J. Farquhar, and N. Kouwen. 1980. “Gas migration and vent design at landfill sites.” Water Air Soil Pollut. 13 (1): 79–97. https://doi.org/10.1007/BF02262526.
Nastev, M. 1998. “Modeling landfill gas generation and migration in sanitary landfills and geological formations.” Ph.D. thesis, Université Laval.
Nastev, M., R. Therrien, R. Lefebvre, and P. Gelinas. 2001. “Gas production and migration in landfills and geological materials.” J. Contam. Hydrol. 52 (1–4): 187–211. https://doi.org/10.1016/S0169-7722(01)00158-9.
Ng, C. W. W., Z. K. Chen, J. L. Coo, R. Chen, and C. Zhou. 2015. “Gas breakthrough and emission through unsaturated compacted clay in landfill final cover.” Waste Manage. 44: 155–163. https://doi.org/10.1016/j.wasman.2015.06.042.
Peng, D. Y., and D. B. Robinson. 1976. “A new two-constant equation of state.” Ind. Eng. Chem. Fundam. 15 (1): 59–64. https://doi.org/10.1021/i160057a011.
Pruess, K. 1987. TOUGH user's guide. Nuclear Regulatory Commission Rep. NUREG/CR-4645. Berkley, CA: Lawrence Berkeley Laboratory.
Rannaud, D., A. Cabral, and S. E. Allaire. 2009. “Modeling methane migration and oxidation in landfill cover materials with TOUGH2-LGM.” Water Air Soil Pollut. 198 (1–4): 253–267. https://doi.org/10.1007/s11270-008-9843-4.
Shan, H. Y., and J. T. Yao. 2000. “Measurement of air permeability of geosynthetic clay liners.” Geotext. Geomembr. 18 (2–4): 251–261. https://doi.org/10.1016/S0266-1144(99)00030-8.
Sharma, H. D., and S. P. Lewis. 1994. Waste containment systems, waste stabilization, and landfills: Design and evaluation. New York: John Wiley & Sons.
Sharma, K. D., and S. Jain. 2019. “Overview of municipal solid waste generation, composition, and management in India.” J. Environ. Eng. 145 (3): 04018143. https://doi.org/10.1061/(ASCE)EE.1943-7870.0001490.
Singh, C. K., A. Kumar, and S. S. Roy. 2018. “Quantitative analysis of the methane gas emissions from municipal solid waste in India.” Sci. Rep. 8 (1): 2913. https://doi.org/10.1038/s41598-018-21326-9.
Stark, T. D., and H. Choi. 2005. “Technical note methane gas migration through geomembranes.” Geosynthetics Int. 12 (2): 120–125. https://doi.org/10.1680/gein.12.2.120.61190.
Stein, V. B., J. P. A. Hettiaratchi, and G. Achari. 2001. “Numerical model for biological oxidation and migration of methane in soils.” Pract. Period. Hazard. Toxic Radioact. Waste Manage. 5 (4): 225–234. https://doi.org/10.1061/(ASCE)1090-025X(2001)5:4(225).
Sughosh, P., N. Anusree, B. Prathima, and G. L. Sivakumar Babu. 2019. “Estimation of landfill Gas emissions and energy recovery potential from landfills of bangalore and mysore: A case study.” In World environmental and water resources congress 2019: Groundwater, sustainability, hydro-climate/climate change, and environmental engineering, edited by G F. Scott, and W. Hamilton, 432–439. Reston, VA: ASCE.
Thiel, R. 1998. “Design methodology for a gas pressure relief layer below a geomembrane landfill cover to improve slope stability.” Geosynthetics Int. 5 (6): 589–617. https://doi.org/10.1680/gein.5.0137.
van Genuchten, M. 1980. “A closed-form equation for predicting the hydraulic conductivity of unsaturated soils.” Soil Sci. Soc. Am. J. 44 (5): 892–898. https://doi.org/10.2136/sssaj1980.03615995004400050002x.
Vargaftik, N. B. 1975. Tables on the thermophysical properties of liquids and gases. 2nd ed. New York: John Wiley & Sons.
Walker, W. R., J. D. Sabey, and D. R. Hampton. 1981. Studies of heat transfer and water migration in soils. Final Report. Fort Collins, CO: Dept. of Agricultural and Chemical Engineering, Colorado State Univ.
Waste Management Paper No. 26A. 1994. Landfill completion: A technical memorandum providing guidance on assessing the completion of licensed landfill sites. London: Dept. of the Environment, HMSO.
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History
Received: Sep 24, 2019
Accepted: Feb 25, 2020
Published online: Jun 22, 2020
Published in print: Oct 1, 2020
Discussion open until: Nov 22, 2020
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