Field investigation and numerical modelling of gas extraction in a heterogeneous landfill with high leachate level.
Environ Sci Pollut Res Int
; 29(51): 76944-76960, 2022 Nov.
Article
em En
| MEDLINE
| ID: mdl-35668271
ABSTRACT
A field gas extraction experiment is carried out at a high-kitchen food large-scale landfill site with high leachate level. The leachate level was decreased to improve the pumping efficiency. Considering the heterogeneity of the municipal solid waste (MSW), the pores in the unsaturated MSW are divided into matrix pores and fractures. A transient dual-porosity model was then developed to analyze the pumping test results. The first and second boundary conditions considering the effect of cover layers of landfills was involved. The results show that the gas flow rate can be increased by 14-37% due to the drawdown of the leachate level. Compared with the single pore model, the dual-porosity model can better predict the field results, indicating that the preferential flow in the landfill caused by the heterogeneity of MSWs is very important. As the pumping pressure increases by a factor of 5, the ratio of fractures to pores wf can be decreased by a factor of 4.4. This may be due to the fact that the fractures will be compressed when the effective stress was increased as the negative pumping pressure was applied. The pumping pressure and the anisotropy value of the MSWs have the greater influence on the well radius of influence. The proposed model can be used for effective design of the field gas pumping experiments. The obtained gas generation rate, gas permeability of the dual porosity MSWs can be useful for gas transport analysis and gas pumping well design for the high-kitchen food content landfills.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
2_ODS3
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Eliminação de Resíduos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Environ Sci Pollut Res Int
Ano de publicação:
2022
Tipo de documento:
Article