Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908, United States.
Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908, United States.
Waste Manag. 2021 Apr 1;124:26-35. doi: 10.1016/j.wasman.2021.01.014. Epub 2021 Feb 14.
There have been several reports of landfills exhibiting temperatures as high as 80 to 100 °C. This observation has motivated researchers to understand the causes of the elevated temperatures and to develop predictive models of landfill temperature. The objective of this research was to characterize the methanogenic activity of microbial communities that were derived from landfill samples excavated from a section of a landfill exhibiting gas well temperatures above 55 °C. Specific objectives were to: (1) determine the upper temperature limit for methane production; (2) evaluate the kinetics of methane generation when landfill-derived microcosms are incubated above and below their excavation temperature and derive a temperature inhibition function; and (3) evaluate microbial community shifts in response to temperature perturbations. Landfill microcosms were derived from 57 excavated landfill samples and incubated within ±2.5 °C of their excavation temperature between 42.5 °C and 87.5 °C. Results showed an optimum temperature for methane generation of ~57 °C and a 95% reduction in methane yield at ~72 °C. When select cultures were perturbed between 5 °C below and 15 °C above their in-situ temperature, both the rate and maximum methane production decreased as incubation temperature increased. Microbial community characterization using 16S rRNA amplicon sequencing suggests that thermophilic methanogenic activity can be attributed to methanogens of the genus Methanothermobacter. This study demonstrated that from a microbiological standpoint, landfills may maintain active methanogenic processes while experiencing temperatures in the thermophilic regime (<72 °C).
已有几篇报道称垃圾填埋场的温度高达 80 至 100°C。这一观察结果促使研究人员了解导致高温的原因，并开发预测垃圾填埋场温度的模型。本研究的目的是描述源自展示出 55°C 以上气体井温度的垃圾填埋场样本的微生物群落的产甲烷活性。具体目标是：（1）确定甲烷产生的最高温度限制；（2）评估在挖掘温度以上和以下培养的垃圾衍生微宇宙中甲烷生成的动力学，并得出温度抑制函数；（3）评估微生物群落对温度扰动的响应。垃圾填埋微宇宙源自 57 个挖掘的垃圾填埋样本，并在 42.5°C 至 87.5°C 之间，在其挖掘温度的±2.5°C 范围内进行培养。结果表明，甲烷生成的最佳温度约为 57°C，在约 72°C 时甲烷产量减少 95%。当选择的培养物在其原位温度以下 5°C 和以上 15°C 之间受到干扰时，随着培养温度的升高，产甲烷率和最大甲烷产量均降低。使用 16S rRNA 扩增子测序进行的微生物群落特征表明，嗜热产甲烷活性可归因于 Methanothermobacter 属的产甲烷菌。本研究表明，从微生物学的角度来看，即使在嗜热区（<72°C），垃圾填埋场也可能保持活跃的产甲烷过程。
