滇池环湖截污干渠错峰技术模拟与分析

为了实现滇池流域截污效果的最大化,基于前期建立的东岸排水管网SWMM模型,结合该区域1995-2016年间降雨资料,研究环湖截污干渠的错峰调蓄技术。根据雨水干渠液位高度执行不同控制模式:当水位低于6.76 m时执行典型污染物浓度阈值控制模式;当水位高于6.76 m时执行典型污染物阈值控制的同时执行液位-污染物通量控制模式。采用SS和TN作为干渠截流的典型污染物控制指标,其控制浓度阈值分别取12和5 mg/L。模拟重现期为0.5~1 a降雨时SS、TN浓度-负荷通量调蓄方案下干渠负荷收集情况,结果表明两种调蓄方案均能有效提高雨水干渠的负荷收集率,提高污水干渠出口浓度,降低雨水径流对污水厂的高水量和低浓度冲击负荷。随着重现期增大,干渠对污染物的高效和最大化收集效果越明显。但是TN调控下污染负荷收集效果优于SS,因此选择TN作为干渠截流的最优典型污染物控制指标。

Simulation and analysis on sewage interception trunk canal staggering peak technology in Dianchi

In order to maximize the Dianchi Lake Basin sewage interception effect, staggered peak storage technology of sewage interception trunk canal was discussed based on the prebuilt SWMM model of the drainage pipe network along the east coast and the rainfall data during 1995-2016. Different control modes were performed according to the rainwater channel liquid level: when the water level was lower than 6.76 meters, the typical pollutant concentration threshold control mode was performed; or else the liquid level - pollutant flux control mode as well as the typical pollutant threshold control were performed when the water level was higher than 6.76 meters. SS and TN were used as typical pollutant control indexes for trunk canal closure, and their control concentration thresholds were 125 mg/L and 5mg/L, respectively. Trunk canal pollutant collection under SS/TN concentration - load flux storage scheme was simulated under the rainfall of 0.5~1a recurrence period, the results showed that both storage schemes can effectively improve the pollutant collection rate, increase the sewer outlet pollutant concentration, and reduce the runoff impact on high water flow and low concentration of the sewage plant. The trunk canal pollutant interception efficiency was higher with the increase of recurrence period. However, pollutant collection under TN storage scheme was better than SS, so TN was chosen as the optimal control index for typical pollutant in trunk canal interception.