高液位污水系统入流入渗评估方法与诊断研究

Study on assessment method and diagnosis of high level sewage system

降雨导致的入流入渗(RDII)是城市污水管网普遍存在的问题,影响城镇排水系统的正常运行,高效、可靠的入流入渗评估与重点区域诊断方法是实现城镇污水处理系统提质增效的重要手段。南方平原河网城市的污水系统经常处于“雨天憋水停泵”的非正常运行状态,此时基于流量数据的常规RDII评估方法无法适用,因此,在传统流量评估基础上,通过引入合理的指标建立一套更具适用性的RDII评估方法意义重大。以一个非正常运行的高液位污水系统为研究对象,根据管网拓扑关系开展了为期8个月的数据监测,共获取流量、液位、电导率3个指标,并依据天气条件将监测数据分为3种工况,通过不同工况下流量与液位数据的对比,评估管网RDII的情况,并进一步依据电导率数据开展了初步的RDII的区域定位工作,识别出发生入流入渗的高可能性区块。

Rainfall-derived inflow and infiltration(RDII)is a common problem in urban sewage pipe network,which harms the regular operation of urban drainage systems.An efficient and relia-ble RDII assessment and localization method is essential for civil drainage management.Some sew-age systems in lowland urban cities are often in abnormal pump outages due to the discharge condi-tion in downstream systems on rainy days,so the conventional methods based on flow rate data cannot be applied.Therefore,it is of great significance to establish a more applicable RDII evalua-tion method by introducing reasonable indicators on the basis of traditional flow rate assessment.In this paper,an abnormal operating sewage system at high water level was taken as the research goal.According to the topology structure of the pipe network,an eight-month data monitoring was carried out,and a total of three types of index data were obtained:flow rate,water level,and electrical conductivity.In addition,the monitoring data were divided into three working conditions according to the weather.By comparing the flow rate and water level data under different working conditions,the RDII was assessed quantitatively.Further preliminary localization work was carried out based on the electrical conductivity data,and the subcatchment with a high RDII probability was eventually identified.