区域氮多部门代谢及回收技术应用影响分析

Multi-sectoral analysis of urban nitrogen metabolism and study on impacts of recycling technologies

模拟了氮元素在水、能源、食品、林业、废物管理等多部门的代谢流动,以苏州为例构建了元素代谢系统分析模型,识别了氮元素代谢的重要部门和关键环节,针对性地提出尿源分离、污泥热解、高温热解、藻类净水等四种氮回收技术及组合,分析技术应用对城市氮元素代谢性能的影响.结果表明:苏州氮元素从外界输入160万t/a,90%来自煤炭和天然气;能源、食品和水部门是氮回收的关键环节;四项氮回收技术组合应用可实现氮元素整体代谢效率提至52%,优化调控效果最好,可促进低氮型社会的构建.

Based on the multi-sectoral system analysis（MSA） model, the present study firstly simulated the nitrogen metabolism flows involving the water sector, the food sector, the forestry department, the energy sector and the waste management department in Suzhou. Secondly, the key sectors and steps of urban nitrogen metabolism were recognized. Thirdly, four targeted recycle technologies of nitrogen were selected： Urine Source Separation Technology, Pyrolysis of Separated Sludge Technology, Livestock Manure Pyrolysis Technology and Algal Water Purification. The impacts of these technologies together with their combined scenarios on the urban nitrogen metabolism were discussed. The intention of this analysis is to provide decision support for the optimization control of urban nitrogen. The main conclusions are as follows： The nitrogen input of Suzhou was 1.6×10-6t/y, 90% of which was from coal and natural gas. The energy sector, food sector and water sector contained steps which were crucial to the recycling of nitrogen. Better effects for the optimization of nitrogen metabolism can be produced by increasing the number of combination circumstance. This could potentially lead to a 52% increase of nitrogen metabolic efficiency at most. Such an increase would be a great contribution to the construction of a low nitrogen society.