高速公路路面雨水径流污染物排放特征研究

为了深入了解高速公路面源污染特征，本文对高速公路路面径流进行了监测分析.尽管径流过程中总悬浮物（TSS）、总化学需氧量（TCOD_Cr）、总氮（TN）和总磷（TP）的浓度以及颗粒物的丰度具有较大的变化幅度，但这些污染物的峰值浓度和颗粒物的峰值丰度基本上出现在径流开始后的10~30 min以内.TSS与TCOD_Cr、TN和TP的浓度之间存在着明显的相关性（r=0.444~0.955；p< 0.005），意味着有相当数量的有机物和营养盐以颗粒物结合态存在.生化需氧量（BOD₅）与TCODcr的关系表明径流中的有机污染物可生化性较差.当降雨量和降雨强度在不同的范围变化时，其对径流污染物事件平均浓度的影响不同.绝大多数情况下，所研究的高速公路都会发生污染物的初期冲刷效应.前30%的径流可以携带46%±15%的TSS、54%±17%的TCOD_Cr、47%±13%的氮、52%±12%的磷以及在数量上占比为51%±12%的颗粒物.按照面源管理实践中80%的悬浮物的削减量的要求，应截留70%的径流，同时可以减少84%的有机物、78%的氮和81%的磷排放负荷.

Characterization on the discharge of pollutants present in highway stormwater

The stormwater from highway was monitored and analyzed to understand the characteristics of non-point source pollution of highway. Although the concentrations of TSS, TCOD, TN and TP and the abundance of particulates in highway stormwater varied greatly through the rainfall events, both the peak concentrations and abundance generally occurred within 10~30 min after the runoff started. TSS was significantly related with TCOD, TN and TP (r=0.444~0.955, p<0.005), indicating a quite quantitative organic matter and nutrients were present in particle-associated forms. Meanwhile, the relationship between BOD₅ and TCOD indicates that the biodegradability of organic pollutants in highway stormwater was poor. When rainfall depth and intensity changed in different ranges, their impacts on event mean concentration (EMC) of pollutant were different. Moreover, first flush phenomenon of pollutants was found in the vast majority of cases. The initial 30% runoff was potential of carrying out 46%±15% TSS, 54%±17% TCOD, 47%±13% nitrogen and 52%±12% phosphorus of their total event loads, coupled with 51%±12% particulates for number, respectively. Based on the requirement of 80% TSS load reduction for stormwater management, 70% runoff should be arrested, which can be coupled with the additional elimination of 84% organic matter, 78% nitrogen and 81% phosphorus.