Development of a low-maintenance measurement approach to continuously estimate methane emissions: A case study.
Development of a low-maintenance measurement approach to continuously estimate methane emissions: A case study.
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DOI：
10.1016/j.wasman.2016.12.006
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发表时间：
2016-12
期刊：
影响因子：
8.1
通讯作者：
S. Riddick;B. Hancock;A. Robinson;S. Connors;S. Davies;Grant Allen;J. Pitt;N. Harris
中科院分区：
文献类型：
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作者：
S. Riddick;B. Hancock;A. Robinson;S. Connors;S. Davies;Grant Allen;J. Pitt;N. Harris
填埋场中有机物的化学分解是甲烷气体（CH4）的重要来源。目前的估计表明，垃圾填埋场占全球人为排放量的3%至19%。垃圾填埋场中微生物对生物地球化学过程及其调控所产生的CH4净排放量受环境约束的不精确知识的制约。因此，填埋场甲烷绝对排放量的不确定性相当大。本研究探讨了一种新的方法来估计的CH4排放量的时间变化，利用气象和CH4浓度测量顺风的垃圾填埋场在英国萨福克，从2014年7月至9月，利用统计数据，这种测量方法提供了较短的时间，但更复杂，即时准确，通量快照。甲烷排放量的计算从CH4浓度测量700米从周边的垃圾填埋场与观察到的浓度范围从背景到46.4 ppm。使用大气扩散模型，我们估计这一时期的平均排放通量为709 μg m−2s− 1，最大值为6.21 mg m−2s−1，反映了地球化学和其他环境控制对净站点排放的广泛自然变化。计算的排放量表明，气象条件对甲烷排放量的大小有影响。我们还调查的因素负责的估计CH4排放量中观察到的大的变异性，并建议，最大的组成部分产生的不确定性的CH4排放量的空间分布在垃圾填埋区。确定使用低维护的方法，本文讨论的结果表明，网络的更便宜，更精确的CH4传感器可以用来测量一个连续的CH4排放量的时间序列从垃圾填埋场，这是不切实际的使用远场的方法，如示踪剂释放方法。尽管这里所描述的方法存在局限性，但这种简单、低维护、低成本的方法可供填埋场运营商使用，通过同时监测羽流平流和CH4浓度来估计时均CH4排放量及其对顺风的影响。
The chemical breakdown of organic matter in landfills represents a significant source of methane gas (CH4). Current estimates suggest that landfills are responsible for between 3% and 19% of global anthropogenic emissions. The net CH4emissions resulting from biogeochemical processes and their modulation by microbes in landfills are poorly constrained by imprecise knowledge of environmental constraints. The uncertainty in absolute CH4emissions from landfills is therefore considerable. This study investigates a new method to estimate the temporal variability of CH4emissions using meteorological and CH4concentration measurements downwind of a landfill site in Suffolk, UK from July to September 2014, taking advantage of the statistics that such a measurement approach offers versus shorter-term, but more complex and instantaneously accurate, flux snapshots. Methane emissions were calculated from CH4concentrations measured 700 m from the perimeter of the landfill with observed concentrations ranging from background to 46.4 ppm. Using an atmospheric dispersion model, we estimate a mean emission flux of 709 μg m−2s−1over this period, with a maximum value of 6.21 mg m−2s−1, reflecting the wide natural variability in biogeochemical and other environmental controls on net site emission. The emissions calculated suggest that meteorological conditions have an influence on the magnitude of CH4emissions. We also investigate the factors responsible for the large variability observed in the estimated CH4emissions, and suggest that the largest component arises from uncertainty in the spatial distribution of CH4emissions within the landfill area. The results determined using the low-maintenance approach discussed in this paper suggest that a network of cheaper, less precise CH4sensors could be used to measure a continuous CH4emission time series from a landfill site, something that is not practical using far-field approaches such as tracer release methods. Even though there are limitations to the approach described here, this easy, low-maintenance, low-cost method could be used by landfill operators to estimate time-averaged CH4emissions and their impact downwind by simultaneously monitoring plume advection and CH4concentrations.