百年一遇大旱后城区降雨径流污染时空差异与可生化性

2009年入秋至2010年春,中国西南地区发生了百年一遇的特大旱灾。为探讨百年一遇大旱后城市降雨径流污染特性,对昆明市典型交通干道路面及屋面进行了三次降雨径流监测,研究了百年一遇大旱后的昆明城区降雨径流污染时空差异与可生化性并同其他城市做了比较。结果表明,径流污染物浓度基本上并未随降雨时间表现出明显的下降趋势。大旱后首场降雨形成的地表径流污染最严重,次日降雨的最轻,路面污染显著高于屋面污染。总体上径流的可生化性较差,不宜用生物法进行处理。同国内外部分城市与2007年调查的昆明比较发现,大旱后的昆明城区屋面和路面径流污染较严重。

Temporal-Spatial Distribution of Pollution and Biodegradability in Precipitation Runoff in Urban Area after the Once-in-a-century Drought

The once-in-a-century drought has parched Southwest China from the autumn of 2009 to the spring of 2010.To probe into the pollution characteristics of urban precipitation runoff,sampling and monitoring of road and roof runoff at Xuefu Road catchment in Kunming City were carried out during the period from March to April 2010.The temporal-spatial distribution of pollution and biodegradability in precipitation runoff,as compared to other cities,was studied.It was found that it was not quite obvious that the concentrations of contaminants decrease with increasing flow time.The pollution of the first runoff after the severe drought was most serious,yet the pollution of the second one was lightest.Road runoff had much greater pollution intensity than roof runoff.Urban surface runoff possessed less biodegradability,so that it was not suitable to adopt common biological treatment of wastewater to purify it.Urban runoff pollution in Kunming after the once-in-a-century drought was serious as compared with other cities concerned and former Kunming in 2007.