摘要
城市屋顶降雨径流是城市面源污染的主要组成部分之一。为了解城市不同屋顶降雨径流的水质特性,以重庆地区5种屋顶为例进行了20场降雨径流的水质监测。研究结果表明,不透水屋顶降雨径流污染物浓度均随降雨历时的延长而降低,混凝土屋顶降雨径流的COD、TP、TN、NH3-N平均浓度分别是瓦屋顶的1.6、1.7、1.4和1.5倍,且不透水屋顶降雨径流总氮的70%~80%为无机氮,总磷的20%~32%为磷酸盐;浅层屋顶降雨径流COD、TN、TP、NH3-N和NO-3-N浓度分别是深层绿色屋顶的0.25~0.26、0.3~0.5、0.07~0.09、0.3~0.6、0.05~0.06倍,且绿色屋顶降雨径流总氮的60%~80%为硝态氮。前期干旱天数和混凝土屋顶径流中的TN、接骨草屋顶径流中的氨氮浓度呈显著正相关关系,混凝土屋顶径流TP浓度与降雨强度显著正相关,降雨持续时间和瓦屋顶径流TSS平均浓度显著正相关。研究结果为城市建筑屋顶降雨径流的科学管理提供了参考。
Runoff from urban imperious roofs has been one of the major sources of urban nonpoint source pollution. We monitored the water quality of 20 rainfall events selected from five different roofs in Chongqing City in order to understand the water quality properties. The results show that pollutant concentrations in runoff from imperious roofs decreased with the extension of rainfall duration. Event mean concentrations( EMCs) of COD,TP,TN and NH3-N in concrete roof runoff are 1. 6,1. 7,1. 4 and 1. 5 times higher than that in tile roof runoff,respectively. 70% ~ 80% of TN is inorganic nitrogen,while 20% ~ 32% of TP is comprised of PO3-4-P in impervious roofs runoff. EMCs of COD,TN,TP,NH3-N and NO-3-N in extensive green roof are 0. 25 ~ 0. 26,0. 3 ~ 0. 5,0. 07~ 0. 09,0. 3 ~ 0. 6 and 0. 05 ~ 0. 06 times lower than that from intensive green roofs. NO-3-N is the major species of TN in all green roofs runoff. Both the EMC of TN for concrete roof and EMC of NH3-N for sambucus roof are positively correlated with the antecedent dry days. In addition,the rainfall intensity is correlated with EMC of TP for tile roof,and rainfall duration is significantly correlated with EMC of TSS for tile roof. The study results provide important reference for the management of roof runoff in urban region.
出处
《环境工程学报》
CAS
CSCD
北大核心
2014年第7期2895-2900,共6页
Chinese Journal of Environmental Engineering
基金
重庆市自然科学基金项目(CSTC,2010BB1351)
重庆文理学院校级科研项目(Z2013CH03,2012PYXM05)
关键词
城市屋顶
降雨径流
水质特征
控制对策
urban roofs
rainfall runoff
characteristic of water quality
control measures
