基于EFDC模型的尾水回用于城市景观水体优化计算

摘要

As the problem of water resources shortage and water pollution was intensifying day by day, it is of greatsignificance to maintain river ecological flow and to ensure that the water quality does not deteriorate because ofstagnation by reusing deeply disposed tail water of sewage plant as landscape water.How to plan the reuse of waterand the location of the outlet to achieve economic, social, environmental and other benefits has become a problemworthy of study.This paper took Penglang sewage treatment plant of Kunshan City as an example, the deeplyprocessed tail water was reused as landscape water in Xiajia river.Based on the three-dimensional unsteady waterquantity model of Xiajia River constructed with environmental fluid dynamics model (EFDC), and considering thebenefits in economic, social, environmental and other aspects, the comprehensive benefits of tail water reuse under 6 design scenarios were studied to determine the optimal operation scheme of the sewage plant.The results show thatthe when the water outlet is chosen to be 4.5km from Taicang Tang river with the drainage direction to the WusongRiver and back flow is 34000 m3 /d, it is the best scheme that finally can be used to reuse the tail water of XiajiaRiver in Kunshan City, judging from the point of maximum economic, social and environmental benefits.In aword, the application of tail water to landscape water can effectively improve water exchange, the position of tailwater flowing into the river from Penglang sewage treatment plant and back flow amount can directly affect the waterexchange cycle and water quality of Xiajia River.%以昆山市内蓬朗污水处理厂深度处理后的尾水回用于城市景观水体夏驾河为例,以环境流体动力学模型(environmental fluid dynamic code, EFDC)构建的夏驾河三维非稳态水量模型为基础,考虑经济、社会、环境等多方面的效益,构建目标函数,研究6种设计情景下尾水回用的综合效益,确定污水处理厂尾水回用的最佳运行方案.结果表明,从经济、社会、环境效益最大化的角度出发,昆山市夏架河尾水回用最优方案为:出水口选为距太仓塘4.5 km处,排水方向为吴淞江,回用流量为3.4万m3/d.尾水回用于景观水体可以有效改善水体交换,蓬朗污水处理厂尾水入河位置及回用量流量直接影响夏驾河换水周期以及夏驾河水质的好坏.