Review of carbon emission in the process of sludge treatment and disposal
不同污泥处理与处置工艺的碳排放

Based on the problem of carbon emission during the process of sludge treatment and disposal, this study summarized its quantity (CO2 and CH4 as the main greenhouse gas) and influential factors. CO2 was the main pattern of C emitted from the process of composting, drying (bio-drying and thermal drying), land application and incineration, while CH4 was major for anaerobic digestion and landfill. The carbon emission elevated gradually from composting to bio-drying, incineration, anaerobic digestion, thermal drying and landfill. Carbon emission of landfill was 8 times equivalent to composting. It can be reduced by improving aeration condition, pre-treatment and co-digestion of various sludges, organic cover corresponding of composting, anaerobic digestion and landfill. Considering the technology of drying and incineration, reduction of energy consumption could effeciently controll the carbon emission. Land application obtained minus carbon emission in the long term. Combination of composting and land application was the optimal scheme to reduce carbon emission during the process of sludge treatment and disposal.