屋面径流中营养物质的分布形态研究
王彪，李田，孟莹莹，任中佳，曹秉寅
同济大学污染控制及资源化研究国家重点实验室，上海200092
摘要：对上海市交通干道旁一处混凝土屋面的6次降雨径流进行监测，分析了屋面径流中颗粒态和溶解态营养物质的出流规律，以期加深对屋面径流污染物的认识和为屋面雨水净化工艺的选择提供理论支持。结果表明，TN的EMC值变化范围为4.208~8.427 mg/L, TP的EMC值变化范围为0.078~0.185 mg/L；DN和PP分别是TN和TP的主要输出形式；随着径流过程中的进行，径流中小颗粒数目比例会逐渐上升。TP浓度变化与TSS基本一致，但TN浓度变化与TSS关系不大。径流后期PN（颗粒态氮）/TSS值增加和小颗粒数目比例上升表明单位质量小颗粒上的氮含量要高于大颗粒上氮的含量。径流前10min的TSS与TP、PP的相关性很好，但径流全过程的相关性稍差，表明单位质量颗粒物上的磷含量在径流全过程中有所变化。溶解态物质污染负荷输出比较稳定，TP比TN更容易出现初期冲刷。此外，单位质量的小颗粒含有更多氮也在一定程度上削弱了TN的初期冲刷效应。
Distribution form of Nutrients in Roof Runoff
WANG Biao, LI Tian, MENG Ying-ying, Ren Zhong-jia, Cao Bing-yin
(State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China)
Abstract: 6 rainfall-runoff events were examined from a concrete roof by a traffic artery in Shanghai to characterize the particle-bound and dissolved nutrients in roof runoff and to get more knowledge about roof runoff pollutants and lay the theoretic foundation for the selection of roof runoff purification methods. Results indicated that event mean concentration (EMC) of TN ranges between 4.208 mg?/L and 8.427 mg/L compared to 0.078 – 0.185 mg/L for TP. DN and PP are respectively the primary forms of TN and TP. During the runoff, the number ratio of small particles is gradually increased. The dynamic behavior of TP is similar to TSS, but the TN-TSS relationship in the course of runoff is not obvious. The increase of both PN/TSS and the number ration of small particles showed that nitrogen (micrograms per gram particle weight) attached to small particles is more than large particles. Regression analysis between TSS and TP & PP of samples in the early 10 min of runoff results in a high R2, but the relationship between TSS and TP & PP of samples in the entire runoff is not as close as the early 10 min, which reflects that the phosphorous quantity attached to the particle changes from the perspective of the entire course of runoff. First flush of TP is stronger then TN because the load discharge of dissolved nutrients is more stable than particle nutrients. In addition, more nitrogen absorbed by the unit mass small particles to a certain degree weakens the first flush of TN.
Key Words: roof runoff, particle-bound nutrient, dissolved nutrient, particle size distribution, first flush
Environmental Science, Vol. 29, No, 11, Nov. 2008