基于水量分析和节点监测的城镇污水管网评估诊断

Evaluation and Diagnosis of Urban Sewage Pipe Network Based on Water Flow Analysis and Node Monitoring

基于现场排查、水量分析、节点监测等方法对某污水泵站所属的排水系统进行初步诊断,并通过溯源分析缩小问题管段范围,进而提出有针对性的解决方案。泵站的雨天流量达到旱天流量的2.4倍,表明泵站上游的排水系统存在较严重的雨污混接现象;泵站的旱天水质浓度显著低于生活污水,大部分时段瞬时样COD在110~140 mg/L之间,混合样COD和BOD_(5)分别为165、81.6 mg/L,表明泵站的上游管网存在旱天外水入流现象;管网节点的雨天水质浓度均有不同程度的下降,其中两条支管的雨天总氮浓度较旱天分别下降了78%和60%,通过溯源分析进一步评估不同支线对泵站水质浓度降低的贡献率,缩小雨污混接管段范围。该方法可为我国污水管网系统的提质增效工作提供参考。

The preliminary diagnosis of a drainage system of a sewage pump station was carried out based on on-site inspection, water flow analysis, node monitoring and other methods. Through tracing analysis, the scope of the problem pipe section was narrowed, and then the targeted solution was proposed. The rainwater flow rate of the pumping station reached 2.4 times that of the dry weather, indicating that there was a serious misconnection of rainwater and sewage pipes in the upstream drainage system of the pumping station. The water quality of the pumping station was significantly lower than that of the domestic sewage in the dry weather. The COD of the instantaneous samples were between 110 mg/L and 140 mg/L most of the time, and the COD and BOD_(5) of the mixed samples were 165 mg/L and 81.6 mg/L, respectively, indicating that there was an inflow of external water in the upstream pipe network of the pumping station in dry weather. The water quality of the pipe network nodes decreased in different degrees in rainy days, and the total nitrogen of the two branch pipes decreased by 78% and 60%, respectively. The contribution rate of different branch pipes to the pollutant concentration reduction in the sewage pump station was further evaluated through tracing analysis, and the scope of misconnection of rainwater and sewage pipes was narrowed. The method can provide reference for improving the quality and efficiency of sewage pipe network systems in China.