摘要
在对南京机场高速公路路面径流Cu,Zn,Cd和Pb4种重金属进行监测的基础上,分析了溶解态和颗粒态重金属随径流变化及污染程度,重点探讨了赋存比例.结果表明：产流时间长的小雨事件中,溶解态浓度在径流初期达到最大,此后逐渐降低,颗粒态重金属浓度波动明显;产流时间较短的中雨事件中,溶解态浓度在降雨前期波动明显,此后逐渐降低趋于平稳,颗粒态浓度随径流冲刷逐渐降低;产流时间短的大雨事件中,溶解态和颗粒态浓度均随径流冲刷稳步降低;重金属总浓度水平较高,Cu,Zn,Pb和Cd4种重金属范围分别为0.048-0.197,0.24-1.03mg/L,5.3-120.6和0.54-2.34μg/L;有4场降雨径流颗粒态Pb的EMC值已超过《地表水环境质量标准》中Ⅲ类标准值50μg/L;Cu的赋存比例fd中值为0.573,同时以溶解态和颗粒态存在,其赋存比例受产流时间影响;Zn,Cd和Pb的fd中值分别为0.179,0.258和0.01,主要存在于颗粒态中.
Dissolved and particulate-bound fraction concentrations of Cu,Zn,Pb and Cd were monitored based on 10 rainfall-runoff events occurred on a representative expressway pavement in Nanjing.Discharge rules,pollution extents and partitioning of dissolved and particulate-bound fraction of heavy metals were evaluated.It is demonstrated that the dissolved fraction concentrations are high initially and then decrease,and the particulate-bound fraction concentrations are fluctuant during those smaller events with long pavement residence time（PRT）.The dissolved fraction concentrations initially fluctuate and then decrease,whilst the particulate-bound fraction concentrations decrease gradually during medium events with medium PRT.In larger events with short PRT,the dissolved and particulate-bound fraction concentrations decrease together.The EMCs（event mean concentration） of total Cu,Zn,Pb and Cd are 0.048 to 0.197 mg/L,0.24 to 1.03 mg/L,5.3 to120.6 μg/L and 0.54 to 2.34 μg/L respectively.Particulate Pb EMCs of four rainfall-runoff exceed the total Pb class Ⅲ standard values 50μg/L of the ＂surface water environmental quality standard＂.The fd median values of Cu,Zn,Pb and Cd are 0.573,0.179,0.01 and 0.258 respectively.Cu partitioned approximate equally in dissolved and particulate-bound fraction influenced by PRT,while Zn and Cd and Pb are generally particulate-bound.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2010年第5期1019-1024,共6页
Journal of Southeast University：Natural Science Edition
基金
江苏省交通科技计划重大资助项目(TZ0761-010)
关键词
路面径流
赋存状态
重金属
road runoff
partitioning fraction
heavy metals
