Greenhouse gas footprint and the carbon flow associated with different solid waste management strategy for urban metabolism in Bangladesh

摘要

Greenhouse gas (GHG) emissions from municipal solid waste (MSW) and associated climate change consequences are gripping attention globally, while MSW management as a vital subsystem of urban metabolism significantly influences the urban carbon cycles. This study evaluates the GHG emissions and carbon flow of existing and proposed MSW management in Bangladesh through scenario analysis, including landfill with landfill gas (LFG) recovery, waste to energy (WtE), and material recovery facility (MRF). The analysis indicates that, scenario H_2 and H_5 emitted net GHGs -152.20 kg CO_2 eq. and -140.32 kg CO_2 eq., respectively, in comparison with 420.88 kg CO_2 eq. of scenario H_1 for managing per ton of wastes during the reference year 2015. The annual horizontal carbon flux of the waste input was 319 Gg and 158 Gg during 2015 in Dhaka and Chittagong, respectively. An integrated strategy of managing the wastes in the urban areas of Bangladesh involving WtE incineration plant and LFG recovery to generate electricity as well as MRF could reverse back 209.46 Gg carbon and 422.29 Gg carbon to the Chittagong and Dhaka urban system, respectively. This study provides valuable insights for the MSW policy framework and revamp of existing MSW management practices with regards to reduction of GHGs emissions from the waste sector in Bangladesh.