Stable isotopic signatures (δ13C, δD) of methane from European landfill sites
Stable isotopic signatures (δ13C, δD) of methane from European landfill sites
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欧洲垃圾填埋场甲烷的稳定同位素特征（δ13C、δD）
DOI：
10.1029/98jd00105
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发表时间：
1998
影响因子：
--
通讯作者：
O. Zwaagstra
中科院分区：
文献类型：
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作者：
P. Bergamaschi;C. Lubina;R. Königstedt;H. Fischer;A. Veltkamp;O. Zwaagstra
采用不同的同位素分析技术（可调谐二极管激光吸收光谱法和同位素比质谱法）对德国和荷兰4个垃圾填埋场的甲烷稳定同位素特征（δ 13 C，δD）进行了表征。直接从天然气收集系统中采集的样品显示出相当均匀的生物成因δ 13 C-δD同位素特征[δ 13 C =（−59.0±2.2）‰ VPDB（n = 104）; δD =（−304±10）‰ VSMOW（n = 46）]。相比之下，在土壤覆盖的垃圾填埋场地区的静态室采取的排放样品表现出相当大的δ 13 C-δD的变化，主要是由于好氧细菌的甲烷氧化的影响，这发生在沼气甲烷遇到大气中的氧气在最高区域的覆盖土壤。从垃圾填埋场覆盖的土壤气体样品清楚地表明，土壤的有氧区域内的渐进同位素富集。甲烷氧化的同位素分馏因子α（δ 13 C）= 1.008±0.004，α（δD）= 1.039±0.026。平均而言，约80%（70-97%）的甲烷在通过覆盖土壤的运输过程中被氧化，而在由新倾倒的废物组成的未覆盖地区没有发现明显的甲烷氧化。总排放量的区域综合δ 13 C值来自垃圾填埋场周围的上风向和下风向测量，显示出很小的时间和站点间变化（δ 13 C =（−55.4±1.4）‰ VPDB（n = 13;四个不同的垃圾填埋场））。确定了两个填埋场的甲烷预算，表明未覆盖和覆盖地区的甲烷表面排放量与甲烷总产量（没有气体收集的填埋场）或甲烷产量和回收量之间的差异（有气体收集系统的填埋场）相比，要低得多。对于这两个垃圾填埋场，甲烷氧化的总比例估计为46%和39%（53%）的甲烷总产量（减去回收）。此外，δ 13 C平衡（将不同排放途径的δ 13 C值与区域综合δ 13 C结果进行比较）表明，通过裂缝或泄漏直接排放的CH 4构成了两个垃圾填埋场进入大气的主要运输途径（约70%）。
The stable isotopic signatures (δ13C, δD) of CH4 from four German and Dutch landfill sites have been characterized using different techniques for isotope analysis (tunable diode laser absorption spectroscopy and isotope ratio mass spectrometry). Samples taken directly from the gas collection systems show fairly uniform, biogenic δ13C-δD isotopic signatures [δ13C = (−59.0±2.2)‰ VPDB (n = 104); δD = (−304±10)‰ VSMOW (n = 46)]. In contrast, emission samples taken with static chambers on soil-covered landfill areas exhibit a considerable δ13C-δD variability, mainly due to the influence of aerobic bacterial CH4 oxidation, which occurs when the biogas CH4 encounters atmospheric oxygen available in the uppermost region of the cover soil. Soil gas samples from the landfill covers clearly show the progressive isotopic enrichment within the aerobic regions of the soil. Isotope fractionation factors due to CH4 oxidation were determined to be α(δ13C) = 1.008±0.004 and α(δD) = 1.039±0.026. On average, about 80% (70–97%) of CH4 is oxidized during the transport through cover soils, while no significant CH4 oxidation was found in uncovered areas consisting of freshly dumped waste. Area-integrated δ13C values of total emissions were derived from upwind-downwind measurements around the landfill and show very little temporal and site-to-site variation (δ13C = (−55.4±1.4)‰ VPDB (n = 13; four different landfills)). CH4 budgets were established for two landfill sites, indicating that projected CH4 surface emissions from uncovered and covered areas are significantly lower compared to total CH4 production (for a landfill without gas collection) or compared to the difference between CH4 production and recovery (for a landfill with a gas collection system). For these two landfill sites the overall fraction of CH4 oxidation is estimated to be 46 and 39% (53%) of total CH4 production (minus recovery). Furthermore, the δ13C balance (comparing the δ13C values of the different emission pathways with the area-integrated δ13C results) implies that direct CH4 emissions via cracks or leakages constituted the major transport pathway (∼70%) into the atmosphere in both landfills.