Characterization of methane oxidation in a simulated landfill cover system by comparing molecular and stable isotope mass balances.
Characterization of methane oxidation in a simulated landfill cover system by comparing molecular and stable isotope mass balances.
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DOI：
10.1016/j.wasman.2017.07.032
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发表时间：
2017-11
期刊：
影响因子：
8.1
通讯作者：
Marcel Schulte;M. Jochmann;T. Gehrke;A. Thom;T. Ricken;M. Denecke;T. Schmidt
中科院分区：
文献类型：
--
作者：
Marcel Schulte;M. Jochmann;T. Gehrke;A. Thom;T. Ricken;M. Denecke;T. Schmidt
生物甲烷氧化可被视为垃圾填埋场的一种后处理方法，以减少与气候有关的甲烷排放。由于对气体排放进行了适当的长期处理，因此评估老化垃圾填埋层中细菌甲烷的氧化行为具有重要的社会和经济意义。最近，其他作者研究了在实验室柱研究中评估甲烷氧化的不同方法。然而，这项工作是第一次对三种独立的方法，(I)质量平衡，(Ii)稳定同位素分析，和(Iii)产物(CO2)和反应物(CH4)的化学计量平衡(CO2/CH4-比率)进行比较，通过在矩形宽土柱上进行稳健的统计验证来估计生物降解性。此外，热成像作为一种潜在的定位细菌甲烷氧化活动区的技术已经与稳定同位素分析和CO2/CH4-比率相结合进行了评估。尽管垃圾填埋场可视为开放系统，但基于封闭系统的稳定同位素分析结果比基于开放系统的计算结果更符合物质平衡。CO2/CH4-比值也符合质量平衡。一般来说，生物降解值的最高值是通过质量平衡确定的，其次是CO2/CH4-比率和稳定同位素分析。事实证明，所调查的表土非常适合作为潜在的覆盖层，在垃圾填埋场的后续阶段，对于35-65微克·m-2d-1的甲烷负荷，最高可去除99%的甲烷。最后，使用稳定同位素分析数据和CO2/CH4-比值来跟踪反应器系统内的微生物活动。结果表明，甲烷消耗和温度升高作为微生物活性较高的原因，具有很好的相关性。
Biological methane oxidation may be regarded as a method of aftercare treatment for landfills to reduce climate relevant methane emissions. It is of social and economic interest to estimate the behavior of bacterial methane oxidation in aged landfill covers due to an adequate long-term treatment of the gas emissions.Different approaches assessing methane oxidation in laboratory column studies have been investigated by other authors recently. However, this work represents the first study in which three independent approaches, ((i) mass balance, (ii) stable isotope analysis, and (iii) stoichiometric balance of product (CO2) and reactant (CH4) by CO2/CH4-ratio) have been compared for the estimation of the biodegradation by a robust statistical validation on a rectangular, wide soil column.Additionally, an evaluation by thermal imaging as a potential technique for the localization of the active zone of bacterial methane oxidation has been addressed in connection with stable isotope analysis and CO2/CH4-ratios. Although landfills can be considered as open systems the results for stable isotope analysis based on a closed system correlated better with the mass balance than calculations based on an open system. CO2/CH4-ratios were also in good agreement with mass balance. In general, highest values for biodegradation were determined from mass balance, followed by CO2/CH4-ratio, and stable isotope analysis. The investigated topsoil proved to be very suitable as a potential cover layer by removing up to 99% of methane for CH4loads of 35–65 g m–2d–1that are typical in the aftercare phase of landfills. Finally, data from stable isotope analysis and the CO2/CH4-ratios were used to trace microbial activity within the reactor system. It was shown that methane consumption and temperature increase, as a cause of high microbial activity, correlated very well.