为降低雨水资源化利用成本, 保证可利用雨水水质, 弃流水质较差的初期降雨及特殊场次降雨成为目前雨水资源化利用的重要途径。因此需要通过长期连续监测降雨和降雪中氮、磷和化学需氧量等关键指标的变化, 确定合理的雨水弃流方式。以天津大学北洋园校区为研究区, 对该区域 2018 年 1- 12 月的降雨和降雪水质进行连续监 测。结果表明: 2018 年 3 月和 4 月降雨中氨氮( 6.75 mg / L) 、总氮( 9.36 mg/ L) 的平均质量浓度分别是全年降雨和 降雪中氨氮和总氮平均质量浓度的 1.5 和 2.1 倍; 春季首场降雨中污染物平均质量浓度远超冬季首场降雪, 冬季空气污染是导致春季首场降雨水质差的主要原因; 空气中各污染物质量浓度对降雨和降雪水质的影响由大到小依次 为 PM215 > PM10 > NO2 > SO2 > CO> O3_8h。与其他季节相比, 春季前两场降雨污染物平均质量浓度高、降水量小, 雨水利用处理成本高, 建议将春季前两场降雨( 降水量< 10 mm) 直接弃流至污水处理厂, 不宜直接进入雨水资源化利用设施。

In order to reduce the cost of rainwater utilization and ensure the quality of rainwater that can be used, discharge first flush and special rainwater with poor water quality has become an important way in rainwater utilization. Therefore, it is necessary to determine the reasonable rainwater discharge method thr ough long-term continuous monitoring of key water quality indicators such as nitrogen, pho sphor us, and chemical oxygen demand in rain or snow water. One-year continuous monitoring of rain and snow water was conducted in the Peiyang Campus of Tianjin University in 2018. Results show that: the average mass concentration of ammonia nitrogen ( 6.75 mg/ L) and total nitrogen ( 9.36 mg / L) in rain and snow water in March and April was about 1.5 and 2.1-folds times the annual average mass concentration of ammonia nitrogen and total nitrogen in rain and snow water; the mass concentration of contaminants in the first r ainwater in spring is much higher than that of the first snow in winter, and air pollution in winter is the key factor for poor r ainwater quality of the first rainfall in spring ; in addition, the influence sequence of the air contaminants to the rainwater and snow water quality was PM2. 5 > PM 10 > NO2 > SO2 > CO> O3_8h . The mass concent ration of contaminants in the first two rainw ater in spring was higher than the other rain and snow water, but the quantity of precipitation was very small. Therefore, the first two rainfall in spring ( precipitation less than 10 mm) may be directly discharged to the wastewater treatment plant rather than directly flow into the r ainwater recycling facilities.

国家自然科学基金( 41772245) ; 京津冀非常规水安全利用技术研发示范( 2016YFC0401405)