Carbon dioxide emission fluxes from active terrace of municipal solid waste semi-anaerobic landfills were determined by the static chamber-gas chromatographic method,and then the impacts of landfill ages and distances from air pipe on carbon dioxide emission fluxes were analyzed.As the results shown,the carbon dioxide emission fluxes near the air pipe area were higher than the other areas,and the significant differences were found between carbon dioxide emission fluxes in different area(the maximum and the ...