Effects of thermal boundary condition on methane oxidation in landfill cover soil at different ambient temperatures

S. Feng, A. K. Leung, H. W. Liu, C. W.W. Ng, L. T. Zhan, R. Chen

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)

Abstract

Microbial aerobic methane oxidation (MAMO) has been considered as an environmental-friendly method for mitigating methane emission from municipal landfill sites. Soil column has in a landfill cover under one-dimensional (1-D) condition. However, most of the published soil column tests failed to simulate 1-D heat transfer due to the use of thermal conductive boundary at the sidewall. In the present study, a heavily instrumented soil column was developed to quantify the effects of thermal boundary condition on the methane oxidation efficiency under different ambient temperatures in landfill cover soil. The sidewall of the soil column was thermally insulated to ensure 1-D heat transport as would have been typically expected in the field condition. Two soil column tests with and without thermal insulation were conducted at a range of controlled ambient temperatures from 15 to 30 °C, for studying how soil moisture, matric suction, gas pressure, soil temperature and gas concentration evolve with MAMO. The test results reveal that ignoring thermal insulation in a soil column test would result in a greater loss of soil heat generation by MAMO and hence oxidation efficiency by up to 100% for the range of temperature considered. When the ambient temperature increased to 30 °C (but less than the optimum temperature for MAMO), the MAMO efficiency increased abruptly at first but then decreased substantially with time, and this is likely due to the accumulation of biomass generated by MAMO.

Original languageEnglish
Pages (from-to)490-502
Number of pages13
JournalScience of the Total Environment
Volume692
Early online date16 Jul 2019
DOIs
Publication statusPublished - 20 Nov 2019

Keywords

  • Biomass accumulation
  • Microbial aerobic methane oxidation
  • Soil column tests
  • Temperature effects
  • Thermal boundary condition
  • Unsaturated soil

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution

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