Scheutz C, Bogner J, Chanton J P, Blake D, Morcet M, Aran C, Kjeldsen P
Institute of Environment and Resources, Technical University of Denmark, Bygningstorvet-Building 115, DK-2800 Lyngby, Denmark.
Waste Manag. 2008;28(10):1892-908. doi: 10.1016/j.wasman.2007.09.010. Epub 2007 Nov 26.
In addition to methane (CH(4)) and carbon dioxide (CO(2)), landfill gas may contain more than 200 non-methane organic compounds (NMOCs) including C(2+)-alkanes, aromatics, and halogenated hydrocarbons. Although the trace components make up less than 1% v/v of typical landfill gas, they may exert a disproportionate environmental burden. The objective of this work was to study the dynamics of CH(4) and NMOCs in the landfill cover soils overlying two types of gas collection systems: a conventional gas collection system with vertical wells and an innovative horizontal gas collection layer consisting of permeable gravel with a geomembrane above it. The 47 NMOCs quantified in the landfill gas samples included primarily alkanes (C(2)-C(10)), alkenes (C(2)-C(4)), halogenated hydrocarbons (including (hydro)chlorofluorocarbons ((H)CFCs)), and aromatic hydrocarbons (BTEXs). In general, both CH(4) and NMOC fluxes were all very small with positive and negative fluxes. The highest percentages of positive fluxes in this study (considering all quantified species) were observed at the hotspots, located mainly along cell perimeters of the conventional cell. The capacity of the cover soil for NMOC oxidation was investigated in microcosms incubated with CH(4) and oxygen (O(2)). The cover soil showed a relatively high capacity for CH(4) oxidation and simultaneous co-oxidation of the halogenated aliphatic compounds, especially at the conventional cell. Fully substituted carbons (TeCM, PCE, CFC-11, CFC-12, CFC-113, HFC-134a, and HCFC-141b) were not degraded in the presence of CH(4) and O(2). Benzene and toluene were also degraded with relative high rates. This study demonstrates that landfill soil covers show a significant potential for CH(4) oxidation and co-oxidation of NMOCs.
除了甲烷（CH₄）和二氧化碳（CO₂）外，垃圾填埋气可能含有200多种非甲烷有机化合物（NMOCs），包括C₂⁺烷烃、芳烃和卤代烃。尽管这些痕量成分在典型垃圾填埋气中的体积占比不到1%，但它们可能带来不成比例的环境负担。这项工作的目的是研究两种气体收集系统上方垃圾填埋覆盖土壤中CH₄和NMOCs的动态变化：一种是带有垂直井的传统气体收集系统，另一种是由透水砾石及上方土工膜组成的创新型水平气体收集层。在垃圾填埋气样本中定量的47种NMOCs主要包括烷烃（C₂ - C₁₀）、烯烃（C₂ - C₄）、卤代烃（包括（氢）氯氟烃（（H）CFCs））和芳烃（BTEXs）。总体而言，CH₄和NMOCs通量都非常小，有正有负。本研究中（考虑所有定量物种）正通量的最高百分比出现在热点区域，主要位于传统单元的单元周边。在与CH₄和氧气（O₂）一起培养的微观世界中研究了覆盖土壤对NMOC氧化的能力。覆盖土壤对CH₄氧化以及卤代脂肪族化合物的同时共氧化表现出相对较高的能力，尤其是在传统单元处。全取代碳（四氯化碳、全氯乙烯、CFC - 11、CFC - 12、CFC - 113、HFC - 134a和HCFC - 141b）在CH₄和O₂存在的情况下不会降解。苯和甲苯也以相对较高的速率降解。这项研究表明，垃圾填埋土壤覆盖层对CH₄氧化和NMOCs共氧化具有显著潜力。
