JWARP  Vol.7 No.13 , September 2015
Use of Evapotranspiration (ET) Landfill Covers to Reduce Methane Emissions from Municipal Solid Waste Landfills
Abstract: Solid waste landfills need to have final covers to 1) reduce the infiltration of rainfall into the waste mass and 2) reduce surface greenhouse gas emissions. Most regulations require that such final covers include hydraulic barriers, such as compacted clays with or without geomembrane. Significant research has been undertaken to allow the use of evapotranspiration-based covers (often termed: Evapotranspiration (ET) Cover, Water Balance Covers, or Phyto Covers) as an alternative to the barrier concept covers. ET covers are designed so that they have the capacity to store water by the soil and also have plants or vegetation to remove the stored water. In ET covers, plant roots can enhance the aeration of soil by creating secondary macropores which improve the diffusion of oxygen into soil. Therefore, biological methane oxidation (a natural process in landfill soils) can be improved considerably by the soil structuring processes of vegetation, along with the increase of organic biomass in the soil associated with plant roots. This paper summarizes a study to investigate the capacity of an ET cover to reduce surface greenhouse gas emissions when implemented on a solid waste landfill. This study consisted of using a numerical model to estimate methane emission and oxidation through an ET cover under average climatic conditions in Bennignton, Nebraska, USA. Different simulations were performed using different methane loading flux (5 to 200 gm-2·d-1) as the bottom boundary. For all simulations, surface emissions were the lowest during the growing season and during warmer days of the year. Percent oxidation is the highest during the growing season and during warmer days. The lowest modeled surface emissions were always obtained during the growing season. Finally, correlations between percent oxidation and methane loading into simulated ET covers were proposed to estimate methane emissions and methane oxidation in ET covers.
Cite this paper: Abichou, T. , Kormi, T. , Wang, C. , Melaouhia, H. , Johnson, T. and Dwyer, S. (2015) Use of Evapotranspiration (ET) Landfill Covers to Reduce Methane Emissions from Municipal Solid Waste Landfills. Journal of Water Resource and Protection, 7, 1087-1097. doi: 10.4236/jwarp.2015.713089.

[1]   Albrecht, B. and Benson, C. (2001) Effect of Desiccation on Compacted Natural Clays. J. of Geotech. and Geoenv. Eng., ASCE, 127, 67-76.

[2]   Benson, C. and Khire, M. (1995) Earthen Covers for Semi-Arid and Arid Climates, ASCE 1995 National Convention on Landfill Closures-Environmental Protection and Land Recovery. Geotechnical Special Publication No. 53, 201-217.

[3]   Stormont, J. and Morris, C. (1998) Method to Estimate Water Storage Capacity of Capillary Barriers. Journal of Geotechnical and Geoenvironmental Engineering, 124, 297-302.

[4]   Nyhan, J.W., Schofield, T.G. and Starmer, R.H. (1997) A Water Balance Study of Four Landfill Cover Designs Varying in Slope for Semi-Arid Regions. Journal of Environmental Quality, 26, 1385-1392.

[5]   Ward, A.L. and Gee, G. (1997) Performance Evaluation of a Field-Scale Surface Barrier. Journal of Environmental Quality, 26, 694-705.

[6]   Hauser, V., Weand, B., Shaw, M. and Wusterbarth, A. (1996) Natural Covers for Landfills: A Closer Look. Proceedings of the 22nd Symposium and Exhibition, American Defense Preparedness Association, Orlando, March 1996.

[7]   Bogner, J., Spokas, K., Burton, E., Sweeney, R. and Corona, V. (1995) Landfills as Atmospheric Methane Sources and Sinks. Chemosphere, 31, 4119-4130.

[8]   Borjesson, G. and Svensson, B. (1997) Seasonal and Diurnal Methane Emissions from a Landfill and Their Regulation by Methane Oxidation. Waste Management and Research, 15, 33-54.

[9]   Abichou, T., Chanton, J., Powelson, D., Fleiger, J., Escoriaza, S., Lei, Y. and Stern, J. (2006) Methane Flux and Oxidation at Two Types of Intermediate Landfill Covers. Waste Management, 26, 1305-1312.

[10]   Kjeldsen, P., Dalager, A. and Broholm, K. (1997) Attenuation of Methane and Nonmethane Organic Compounds in Landfill Gas Affected Soils. Journal of Air & Waste Management Association, 47, 1268-1275.

[11]   Scheutz, K., Kjeldsen, P., Chanton, J., Blake, D. and Bogner, J. (2003) Comparative Oxidation and Net Emissions of CH4 and Selected Non-CH4 Organic Compounds in Landfill Cover Soils. Environmental Science and Technology, 37, 5150-5158.

[12]   Huber-Humer, M., Gebert, J. and Hilger, H. (2008) Biotic Systems to Mitigate Landfill Methane Emissions. Water Management Research, 26, 33-46.

[13]   Bogner, J. and Spokas, K. (1993) Landfill CH4: Rates, Fates, and Role in Global Carbon Cycle. Chemosphere, 26, 369-386.

[14]   Abichou, T., Mahieu, K., Chanton, J., Romdhane, M. and Mansouri, I. (2011) Scaling Methane Oxidation: From Laboratory Incubation Experiments to Landfill Cover Field Conditions. Waste Management, 31, 978-986.

[15]   Abichou, T., Mahieu, K., Yuan, L., Chanton, J. and Hater, G. (2009) Effects of Compost Biocovers on Gas Flow and Methane Oxidation in a Landfill Cover. Waste Management, 29, 1595-1601.

[16]   Yuan, L., Abichou, T., Chanton, J., Powelson, D. and De Visscher, A. (2009) Long Term Numerical Solution of Methane Transport and Oxidation in a Compost Biofilter. Practice Periodical of Hazardous Toxic and Radioactive Waste Management, 13, 196-202.

[17]   Abichou, T., Yuan, L. and Chanton, J. (2008) Estimating Methane Emission and Oxidation from Earthen Landfill Covers. Geocongress 2008: Geotechnics of Waste Management and Remediation (GSP), New Orleans, 9-12 March 2008, 80-87.

[18]   Abichou, T., Johnson, T., Mathieu, K., Chanton, J., Romdhane, M. and Mansouri, I. (2010) Developing a Design Approach to Reduce Methane Emissions from California Landfills. In: Fratta, D., Muhuntan, B. and Pupala, A., Eds., GeoFlorida 2010: Advances in Analysis, Modeling & Design, ASCE, Geotechnical Special Publication No. 199, Baltimore, 2878-2887.

[19]   Spokas, K. and Forcella, F. (2009) Software Tools for Weed Seed Germination Modeling. Weed Science, 57, 216-227.

[20]   Jin, Y. and Jury, A. (1996) Characterizing the Dependence of Gas Diffusion Coefficient on Soil Properties. Soil Science Society of America Journal, 60, 66-71.

[21]   Stein, V. B., Hettiaratchi, J. and Achari, G. (2003) Numerical Model for Biological Oxidation and Migration of Methane in Soils. Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management, 5, 225-234.

[22]   Freijer, J. (1994) Calibration of Jointed Tube Model for the Gas Diffusion Coefficient in Soils. Journal of the American Society of Soil Science, 58, 1067-1076.

[23]   Kightley, D., Nedwell, D. and Cooper, M. (1995) Capacity for Methane Oxidation in Landfill Cover Soils Measured in Laboratory Scale Soil Microcosms. Journal of Applied Environmental Microbiology, 61, 592-601.

[24]   Moldrup, P., Olesen, T., Gamst, J., Schjønning, P., Yamaguchi, T. and Rolston, D.E. (2000) Predicting the Gas Diffusion Coefficient Inrepacked Soil: Water-Induced Linear Reduction Model. Soil Science Society of America Journal, 64, 1588-1594.