Experimental study of methane oxidation efficiency in three configurations of earthen landfill cover through soil column test - Details

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Abstract：

Soil　column　tests　were　conducted　to　investigate　methane　oxidation　efficiency　in　three　configurations　of　earthen　landfill　cover　under　two　drying　stages　separated　by　an　applied　rainfall,　including　the　monolithic　evapotranspiration　(ET)　cover,　the　cover　with　capillary　barrier　effect　(CCBE)　and　the　three-layer　cover.　Comprehensive　measurements　were　also　documented　for　water–gas　response　in　soil　for　analyzing　the　experimental　outcomes.　The　maximum　methane　oxidation　efficiency　of　three-layer　cover,　monolithic　ET　cover,　and　CCBE　were　about　71　%,　62　%　and　58　%,　respectively.　This　was　because　the　three-layer　cover　had　the　largest　oxygen　(O2)　concentration　in　soil　above　depth　of　400　mm,　where　methane　oxidation　mainly　occurred.　This　was　due　to　the　good　airtightness　of　the　bottom　hydraulic　barrier　layer,　which　led　to　the　lowest　air　pressure　above　depth　of　400　mm,　thereby　promoting　the　entry　of　atmospheric　O2　into　the　soil.　The　monolithic　ET　cover　generally　had　a　larger　methane　oxidation　efficiency　than　CCBE　during　the　first　drying　stage　by　up　to　12　%,　while　the　trend　reversed　overall　during　the　second　drying　stage,　likely　due　to　the　enhanced　air-tightness　of　CCBE　caused　by　higher　soil　water　content　after　rainfall　induced　by　the　capillary　barrier　effects.　The　methane　oxidation　efficiency　for　each　landfill　cover　became　lower　by　up　to　30　%　during　the　second　drying　stage　than　that　during　the　first　drying　stage,　owing　to　the　higher　water　content　during　the　second　drying　stage　after　rainfall,　leading　to　a　larger　gas　pressure　and　hence　a　lower　O2　concentration　at　shallow　soil.　©　2024　Elsevier　Ltd

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Atmospheric pressure Capillarity Land fill Soil testing Water content

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[ 1 ] [Liu, H.W.]Zijin School of Geology and Mining, Fuzhou University, Fujian Province, Fuzhou City, China
[ 2 ] [Liu, H.W.]Key Laboratory of Geohazard Prevention of Hilly Mountains, Ministry of Natural Resources (Fujian Key Laboratory Of Geohazard Prevention), Fujian Province, Fuzhou City, China
[ 3 ] [Huang, Y.]Zijin School of Geology and Mining, Fuzhou University, Fujian Province, Fuzhou City, China
[ 4 ] [Feng, S.]College of Civil Engineering, Fuzhou University, Fujian Province, Fuzhou City, China
[ 5 ] [You, S.Q.]Zijin School of Geology and Mining, Fuzhou University, Fujian Province, Fuzhou City, China
[ 6 ] [Hong, Y.]Key Laboratory of Offshore Geotechnical and Material Engineering of Zhejiang Province, Zhejiang University, Zhejiang Province, Hangzhou City, China
[ 7 ] [Shen, L.D.]Key Laboratory of Ecosystem Carbon Source and Sink, School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Jiangsu Province, Nanjing City, China