Key Laboratory of Yangtze Aquatic Environment, Ministry of Education, College of Environmental Science and Engineering of Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
Waste Manag. 2013 Jan;33(1):123-8. doi: 10.1016/j.wasman.2012.06.024. Epub 2012 Aug 11.
About 20 million tonnes of sludge (with 80% moisture content) is discharged by the sewage treatment plants per year in China, which, if not treated properly, can be a significant source of greenhouse gases (GHGs) emissions. Anaerobic digestion is a conventional sewage sludge treatment method and will continue to be one of the main technologies in the following years. This research has taken into consideration GHGs emissions from typical processes of sludge thickening+anaerobic digestion+dewatering+residue land application in China. Fossil CO(2), biogenic CO(2), CH(4,) and avoided CO(2) as the main objects is discussed respectively. The results show that the total CO(2)-eq is about 1133 kg/t DM (including the biogenic CO(2)), while the net CO(2)-eq is about 372 kg/t DM (excluding the biogenic CO(2)). An anaerobic digestion unit as the main GHGs emission source occupies more than 91% CO(2)-eq of the whole process. The use of biogas is important for achieving carbon dioxide emission reductions, which could reach about 24% of the total CO(2)-eq reduction.
中国每年有大约 2000 万吨含水率 80%的污泥（sludge）排出，如果处理不当，可能成为温室气体（greenhouse gases，GHGs）排放的一个重要来源。厌氧消化（anaerobic digestion）是一种传统的污水污泥处理方法，在未来几年仍将是主要技术之一。本研究考虑了中国污泥浓缩+厌氧消化+脱水+剩余物土地应用的典型工艺的 GHGs 排放。分别讨论了化石 CO(2)、生物 CO(2)、CH(4) 和避免的 CO(2)作为主要对象。结果表明，总 CO(2)-eq 约为 1133 千克/吨干物质（包括生物 CO(2)），而净 CO(2)-eq 约为 372 千克/吨干物质（不包括生物 CO(2)）。厌氧消化单元作为主要的 GHGs 排放源，占整个过程 CO(2)-eq 的 91%以上。沼气的利用对于实现二氧化碳减排非常重要，可达到总 CO(2)-eq 减排的 24%左右。
