The effect of atmospheric pressure on CH4 and CO2 emission from a closed landfill site in Manchester, UK

Abstract

A time series study was conducted to ascertain the effect of barometric pressure on the variability of CH4 and CO2 concentrations in a closed landfill site. An in situ data of methane/carbon dioxide concentrations and environmental parameters were collected by means of an in-borehole gas monitor, the GasClam (Ion Science, UK). Linear regression analysis was used to determine the strength of the correlation between ground-gas concentrations and barometric pressure. The result shows CH4 and CO2 concentrations to be variable with weak negative correlations of 0.2691 and 0.2773, respectively, with barometric pressure over the entire monitoring period. Although the R(2) was slightly improved by considering their concentration over single periods of rising and falling pressure, single periods of rising pressure and single periods of falling pressure, their correlations remained insignificant at 95% confidence level. The result revealed that atmospheric pressure--the acclaimed major control on the variability of ground-gas concentration--is not always so. A case was made for the determination of other possible controls such as changes in temperature, soil permeability, landfill water depth, season, and geology of the borehole and also how much of control each factor would have on the variability/migration of CH4 and CO2 concentrations from the studied landfill.

Considerations for choosing appropriate healthcare waste management treatment technologies: A case study from an East Midlands NHS Trust, in England

“…However, 'deep landfill' (cell separated landfill) of offensive waste (referred to in the European Waste Catalogue (EWC) as 18.01.04) (EC, 2008), is still permitted at landfill sites with the appropriate licences, and makes up a significant volume of segregated healthcare waste (DOH, 2014a). However, opponents have highlighted that landfills contribute to greenhouse gases (GHGs) (Nwachukwu and Anonye, 2012), and the significant scrubbing required of landfill gas, further increases its carbon inefficiency (Nock and Walker, 2014). In addition, the EU Landfill Directive requires a reduction to 35% of the 1995 level of biodegradable landfill waste by 2016 (2020 derogation at the latest) (DOH, 2014a).…”

The utility of concentration duration curve in CH4 and CO2 risk assessment

“…Also crucial is the information about the general processes taking place on the site which is learned from other sites. Such information includes the methane generation rate, and the potential methane generation capacity (Nwachukwu and Anonye, 2013). This information is used to produce what is known as a Conceptual Site Model (CSM) (NHBC, 2008;EA, 2004;Boult et al, 2011).…”

The Utility of Purge and Recovery Testing in Ground-Gas Flux Risk Assessment

“…Ground-gas monitoring is an important aspect of the investigation and management of contaminated sites, as the data is critical to the process of risk assessment (Morris et al, 2008;Friedrich and Trois, 2011;Ashraf et al, 2014;Nagamori et al, 2016;Talbot and Cards, 2019). Ground-gas concentration and its flux are the two the most important parameters in ground-gas risk assessment (Jewell and Hallam, 2012;British Standard 8576, (2013); Nwachukwu and Anonye, 2013). This is because the concentration is used to assess their local risks (explosion and asphyxiation) and flux, andt heir global risk (warming) (Boyle and Witherington, 2007;Katy et al, 2009;Boucher et al, 2009;Wilson et al, 2017;Wilson et al, 2018;Feuyit et al, 2019).…”

“…The method is analogous to those used in hydrogeology. While hydrogeologists use this test in characterizing aquifer productivity in which the fluid level in a borehole is perturbed and the recovery period is monitored (Wilson et al, 2006;Nwachukwu and Anonye, 2013); in our case, the fluid is ground-gas. With time-series gas concentration data, a similar approach would adopted.…”