中水回用对城市给排水的影响研究——以常州市为例

水资源短缺是影响城市可持续发展的主要限制因子之一。污水回用是解决城市水危机的重要途径。目前中国的中水回用水平较低,提高污水回用水平对水资源的可持续利用和水环境保护具有重要意义。以常州市为例,全面分析了城市经济社会发展对水资源的作用机制,构建了城市水资源开发利用的系统动力学模型,设置不同中水回用情景,比较不同情景对城市水资源供给状况、水环境状况和社会影响。结果表明：如果维持现状中水回用规模不变,常州市未来将出现供水短缺,至2020年缺水量达到2.49亿m3,同时污水排放量达到14.97亿m3;如果中水回用率逐步提高到20%和40%,用水和排污总量将得到有效控制,但仍会持续增长;如果2020年中水回用率达到60%,常州市的用水和排水规模将维持不变,实现供排水的总量平衡。三种提高回用率的控制方案对地区生产总值的影响均低于0.1%,具有较高的经济可行性,研究成果可为常州市未来水资源利用和水环境保护规划的制定提供借鉴和指导。

Impacts of Reclaimed Water Use on Water Supply and Drainage in Changzhou City

Water shortage is one of the most serious problems in the world and water reuse is considered as a solution.Improving water utilization efficiency is of great significance to save water resources and to protect water environment.Taking Changzhou as a study case,a system concerning economy,population,water supply,water use,water discharge and water reuse is built with SD model.The results show that Changzhou will suffer from serious water shortage in the future with shortage amount of 249 million m3 and 1.497 billion m3 of wastewater by 2020.In the low and middle control schemes,water demand and wastewater is less than the previously mentioned projection,but will continue to increase.In the high target scheme,water supply and discharge would be balanced during 2008-2020.The net cost of improving reuse rate is less than 0.5% of the GDP in Changzhou.The results are expected to provide some reference for wastewater management in Changzhou.