膜进样质谱仪法在测量水体中过饱和溶解氮气的应用研究  

Application of Membrane Injection Mass Spectrometer in the Measuring of Supersaturated Dissolved Nitrogen in Water

作　　者：孙干 袁酉铨 薛敬阳 卢晶莹 孙志峰 邢龙 谭升魁 冯镜洁[2] SUN Gan;YUAN Youquan;XUE Jingyang;LU Jingying;SUN Zhifeng;XING Long;TAN Shengkui;FENG Jingjie(China Three Gorges Construction Engineering Corporation,Chengdu 610041,Sichuan,China;State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,Sichuan,China;China Three Gorges Corporation,Wuhan 430010,Hubei,China;River Basin Complex Administration Center,Three Gorges Corporation,Yichang 443134,Hubei,China)

机构地区：[1]中国三峡建工(集团)有限公司,四川成都610041 [2]四川大学水力学与山区河流开发保护国家重点实验室,四川成都610065 [3]中国长江三峡集团有限公司,湖北武汉430010 [4]中国长江三峡集团有限公司流域枢纽运行管理中心,湖北宜昌443134

出　　处：《水力发电》2024年第3期6-11,119,共7页Water Power

基　　金：国家自然科学基金面上项目(52279073);中国三峡建设管理有限公司技术服务项目(合同号:JG/18095B)。

摘　　要：高坝泄洪会导致水中溶解气体过饱和,使鱼类患气泡病甚至死亡。为探究大坝泄洪条件下,真实水体中的过饱和溶解氮的生成及其随泄洪条件的时空变化规律,利用膜进样质谱仪开展向家坝水电站泄洪条件下溶解氮的测量。结果表明,野外条件下采样运输过程中溶解气体的释放损失,导致膜进样质谱仪测量得到的溶解氮含量比通过利用总溶解气体和溶解氧的现场实测值计算得到的溶解氮含量低;利用质谱仪测量得到的溶解氮测值与总溶解气体测值之间同增的趋势性较好,但溶解氮测值与溶解氧测值之间相关关系较差。总结下来,向家坝电站泄洪导致坝下溶解氮、溶解氧和总溶解气体均达到过饱和,溶解气体饱和度在横向上基本均匀分布;受上游溪洛渡泄洪影响,向家坝坝前仍保持一定程度的溶解气体过饱和,并在垂向上表现出不均匀分布;泄洪生成的溶解气体饱和度随泄洪流量的增大而增大。为保证测量精度,建议原位开展测量,避免采样后长距离运输造成溶解气体的损失;在测量条件不满足的情况下,建议测量总溶解气体和溶解氧后进行溶解氮值换算。The flood discharge of high dam will lead to the supersaturation of dissolved gas in water,which causes fish to suffer from bubble disease and even death.In order to explore the generation of supersaturated dissolved nitrogen(DN)in natural water and its temporal and spatial variation with flood discharge conditions,the DN content during the flood discharge of Xiangjiaba Hydropower Station is measured using membrane injection mass spectrometer(MIMS).The results show that,(a)due to the dissolved gas loss during sampling and transportation process,the DN content measured by MIMS is lower than that calculated by using the field measured values of total dissolved gas(TDG)and dissolved oxygen(DO);and(b)the DN and TDG content measured by MIMS shows a trend of simultaneous increasing,while the correlation between DN and DO content is poor.In conclusion,the flood discharge of Xiangjiaba Hydropower Station results in the supersaturation of DN,DO and TDG in the downstream of dam,and the dissolved gas shows a basically uniform distribution trend in lateral.Affected by the flood discharge of Xiluodu Hydropower Station,the dissolved gas is still supersaturated to a certain extent in the reservoir near Xiangjiaba dam,and shows an uneven distribution in vertical.Generally,the dissolved gas content is increased with the increase of discharge flow.In order to ensure the measuring accuracy,it is recommended to carry out the measurement in situ to avoid the loss of dissolved gas caused by long-distance transportation after sampling,and when the observation and measuring conditions are not satisfied,it is recommended to obtain the DN content by converting the measured values of TDG and DO contents.

关 键 词：溶解氮 过饱和 测量 膜进样质谱仪 高坝泄洪 向家坝水电站 

分 类 号：X853[环境科学与工程—环境工程]