典型屋面路面雨水污染状况调查与回收利用试验

Investigation of Pollution and Experiment of Reclamation for Typical Rainwater Collected from Building Roof and Pavement

对屋面雨水水质进行分析是回收利用屋面雨水的前提。该文选择西安市典型屋面雨水为研究对象,分析研究区域范围内屋面雨水前后水质变化规律。结果表明西安市雁塔区房屋雨水中主要污染物为COD、SS、TN、TP,水质状况未达到地表水水环境质量Ⅳ类标准和景观娱乐用水水质C类。采集的初期雨水在放置24 h后,污染物COD、SS、TN、TP显著减少。未落地雨水减少量最小,路面雨水减少量最大,原因是路面雨水中的颗粒物、杂质附着沉淀使得指标下降。不同采样时间段内的雨水污染物,以及污染物含量有差异,未落地雨水在整个采样时间段内各项指标稳定,变化较小;屋面雨水在前20 min内COD、SS、TN、TP下降最快,后期减缓;路面雨水前40 min内COD、SS、TN、TP下降较快。另外未落地雨水可直接用于回收利用,但回收难度大,屋面雨水和路面雨水污染比较严重,集中收集处理后可利用。

Analyzing the quality of roof rainwater is the precondition of recycling roof rainwater. On the basis of the typical roof rainwater in Xi＆#39;an,the regulations of roof rainwater quality within the study region were analyzed. The results show that the main pollutants of rain are COD,SS,TN,TP,and the water quality can not reach the Surface Water Environmental Quality Standards class IV and Water Quality Standard for Scenery and Recreation Area class C. When the initial rainwater is collected and placed after 24 hours,COD,SS,TN and TP reduce significantly;the decrement of rainwater which does not fall to the ground is the smallest,while the decrement of pavement rainwater is the biggest. The reason is that the particles and impurities in the rainwater of pavement precipitate and attach,which make the indicators down. There are differences between pollutants and contents in different sampling period of rainwater,the indicators of rainwater which does not fall to the ground are stable in the whole sampling period;COD,SS,TN and TP of roof rainwater drop fastest within 20 minutes and in the later period slow down;COD,SS,TN and TP of pavement rainwater decrease rapidly within 40 minutes. The rainwater which does not fall to the ground water can be directly used in reclamation,but directly reclamation is difficult to realize. If the pollution of roof rainwater and pavement rainwater are serious,roof rainwater and pavement rainwater can be used after centralized and treated.