昆明市主城区生活污水排放量日间和日内排放规律

Sewage discharge characteristics during one day in the central part of Kunming

为了系统识别昆明市主城区生活污水排放规律,该文采用基于土地利用的方法,通过现场监测和数理统计分析开展研究。依据土地利用现状,选取居住用地(R单元)、公共用地(P单元)和商业用地(C单元)作为典型用地单元,于2013年3月至6月开展了地块排放污水水量监测,运用快速Fourier变换(FFT)识别污水排放的周期性,进而定义污水排放指数(SDI)并构造出典型日污水排放变化特征曲线,获得昆明市主城区生活污水排放规律如下:各单元的污水量均有以24.4h和12.2h为周期的规律性,其中24.4h的周期性比12.2h更显著;假日的变化曲线相比工作日而言,R单元和C单元存在时间上的延迟,P单元则存在峰值降低的现象;R单元、P单元和C单元的污水排放日内变化则分别呈现出W型、尖峰型和V型特征,波峰、波谷、平台期的个数和出现时间均相对固定;R单元、P单元和C单元的时变系数分别为1.58、3.18和1.48。识别的规律可作为模型模拟的点源输入,用于筛选管网设计改造、污水厂优化运行、雨污溢流控制和内涝防治等方案。

The discharge characteristics of sewage in the central part of Kunming were analyzed using a land use distribution method with field monitoring and statistics analyses. Residential, public and commercial areas were selected as typical land use types in the study. The sewage discharge quantities at six different sites were monitored between March and June in 2013. Fast Fourier Transforms were used to identify the periodicity of the sewage discharge characteristics with the ratio of the instantaneous flow rate to the average daily flow rate defined as the sewage discharge index （SDI） used to identify the discharge sanitary sewage characteristics in a typical day. The results indicate that the sewage discharge rates within the residential, public and commercial areas all have 24.4 hour and 12.2 hour periods, with the 24.4 hour period being more significant. Non-work days have delays in the residential and commercial area flow rates compared with work days with lower peaks in public areas. The daily curves for the three areas are ＂W-shaped＂, ＂Acuminate-Peak-shaped＂ and ＂V shaped＂ with relatively fixed numbers and times of the peaks, troughs and platforms with hourly variation coefficients of 1.58, 3.18 and 1.48. The identified discharged characteristics can be used as model inputs for drainage network designs, waste water treatment plants optimizations, overflow control and water logging prevention.