Global warming potential of typical rural domestic waste treatment modes in China: a case study in Ankang.

Abstract

The global problem of domestic waste management increases with rapid population growth and with economic and urban development. In developing countries, treatment of rural domestic waste (RDW) is distinguished from urban waste. Quantitative assessment of greenhouse gas emissions from RDW disposal treatment is needed to achieve carbon neutrality. Reliable global warming potential (GWP) assessments of RDW are not differentiated in the widely accepted "urban-rural integration" centralized disposal model. We considered five different scenarios for RDW management. Scenario 1 (S1), unsanitary landfill (open-air dump); scenario 2 (S2), sanitary landfill; scenario 3 (S3), incineration; scenario 4 (S4), biological + incineration; and scenario 5 (S5), classification + composting + sanitary landfill + recycling. Life cycle assessment was used for GWP, and sensitivity analysis was calculated to point out the sensitive parameter. We found that the mean GWP ranged from 5.14 × 104 to 2.31 × 105 kg CO2-equivalents. Pollution from untreated RDW with landfill gas emissions led to large contributions under all scenarios. The collection and transportation ratio was sensitive to all scenarios, and we found that, if the recyclable materials separated at source were not used efficiently, the impact on GWP would be greater than under the unclassified waste scenarios. A "new urban-rural integration" mode (S5) that included household classification, village collection, town transfer, and county and urban disposal was introduced for RDW management. These quantitative results have a great potential for promoting effective RDW management in China and other developing countries.