城市污水污泥处置方式的温室气体排放比较分析

针对我国现在主流的城市污水污泥处置方法:填埋,焚烧,堆肥。用IPCC中推荐的方法和缺省值,对处置过程中产生的温室气体的直接排放、间接排放和替代排放做了计算和分析。填埋过程计算排放的温室气体有CH4,焚烧过程计算排放的有温室气体CO2和N2O,堆肥过程计算的排放的有温室气体CO2和N2O,最终比较的结果都折算成CO2的排放。结果表明,污泥填埋、焚烧、堆肥所产生的CO2的净排放量分别为695.847 kg CO2/t、443.643 kg CO2/t、511.817 kgCO2/t。由于考虑了堆肥以后的有机肥利用,从减排以及污泥资源化的角度分析,得出堆肥是相对好的污泥处置方式。

Analysis on greenhouse gas emissions from different sewage sludge treatments and disposal processes

At the present time, sanitary landfills, incineration and composting are the main disposal methods of sewage sludge. The discharge amount of greenhouse gases exhausted during disposing process was calculated and analyzed with the method and default value recommended by the IPCC model. The emitting ways of involving greenhouse gases included direct discharge, indirect discharge and alternative emission. CH₄ was the gas considered during landfills process. And for the incineration and composting process, CO₂ and N₂O were involved. The emission of CH₄ and N₂O was converted to that of CO₂. The net emissions of CO₂ during sanitary landfills, incineration and composting processed were 695.847 kg CO₂/t, 443.643 kg CO₂/t, 511.817 kg CO₂/t, respectively. Organic fertilizer obtained from sewage sludge composting can be reutilized. Therefore, composting may be a promising technology for sewage sludge disposal in view of carbon emission reduction and resource utilization.