1644 / 2019-08-24 14:52:10

利用硝酸盐同位素定量识别高度城市化地区河流中硝酸盐来源及贡献

2、地球化学 > 专题9：稳定同位素与生物地球化学循环

The artificial rivers in the urban are blocked by pumping stations, water gates and dams resulting in the poor water flow and the single water supplemented by rainfall and runoff, which leads to the particularity of river environment. In this study, the temporal and spatial characteristics of nitrate source and contribution in urban river water were quantitatively analyzed by using dual isotopes (δ15N-NO3 and δ18NO3). The main sources of nitrate in urban river are manure and septic waste (M&S), NH4+ in fertilizer and precipitation (NP), soil N (SN)，runoff pollurtant of non-point source(NPS) and atmospheric precipitation (AP). According to the results of the Bayesian mixing model, the nitrate in urban river water mainly comes from M&S with the average of 31.4%, SN (31.5%) and NP (23.9%) possibly from sewage. The monthly accumulative rainfall affects the contribution of manure and septic waste, and the both have the same change trend. Land uses and functional area types have influences on the contribution of nitrate source in different rivers. The study area is mainly a rain and sewage diversion and drainage system, so the reduction of urban rainfall runoff is an important means to control water pollutants.