广州城区雨水径流非点源污染特性及污染负荷

以广州市新河浦社区部分排水区为研究对象,将研究区域划分为居住区、马路、草地3种典型下垫面,在各典型下垫面分别进行若干场雨水径流水质监测,主要分析雨水径流中的化学需氧量(COD)、生物需氧量(BOD5),以及总悬浮物固体(TSS)、总氮(TN)、总磷(TP)、氨氮等污染物的浓度,探讨TSS和COD的相关性,揭示污染物的时空变化规律和径流的初期冲刷效应。基于暴雨径流管理模型(SWMM)建立了研究区域降雨径流非点源污染的模型,根据研究区域的水质监测资料率定模型参数,结果表明:水样中TSS和COD的相关性不明显;居住区、马路存在较为明显的初期冲刷效应,草地的初期冲刷效应不如居住区和马路明显;所建立的非点源污染模型具有较高的精度,利用该模型分别模拟不同重现期、不同降雨类型及不同下垫面类型的非点源污染负荷,所得负荷量结果较为合理,可以为城市雨水径流非点源污染的控制提供参考依据.

Characteristics and Load of Non-Point Source Pollution of Urban Rainfall Runoff in Guangzhou, China

In this paper,a part of the drainage area in Xinhepu Community in Guangzhou city was selected as the research region and was divided into three typical types of land surfaces,namely the residential area,the road and the grass.Then,the water quality for several rainfall events on the three types of land surfaces was monitored in terms of chemical oxygen demand(COD),biological oxygen demand(BOD5) as well as the concentrations of total suspended solids(TSS),total nitrogen(TN),total phosphorus(TP) and ammoniacal nitrogeon.Moreover,the relationship between TSS and COD was discussed,and the space-time change law of the pollutants as well as the first flush effect of the runoff was analyzed.Finally,a non-point source pollution model of rainfall runoff was es-tablished based on the storm water management model(SWMM) and the corresponding model parameters were determined according to the observation data.The results show that(1) there is no obvious relationship between TSS and COD;(2) the first flush effect is obvious in both the residential area and the road,but is not obvious in the grass;and(3) the proposed model is of high accuracy and it helps to reasonably simulate the non-point source pollution load varying with the rainfall intensity,the rainfall type and the recurrence period,and provides a reference for the non-point source pollution control of urban runoff.