降水驱动下大港河硝酸盐迁移转化过程及来源解析  

Identification of nitrate sources and transformations during precipitation processes in Dagang River basin

作　　者：王俊 亢晓琪 吴亚丽 牛远[1] 余辉[1] WANG Jun;KANG Xiao-qi;WU Ya-li;NIU Yuan;YU Hui(Institute of Lake Ecological Environment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;College of Resources and Environment,Henan Agricultural University,Zhengzhou 450002,China;Institute of Surface-Earth System Science,School of Earth System Science,Tianjin University,Tianjin 300072,China)

机构地区：[1]中国环境科学研究院湖泊生态环境研究所,北京100012 [2]河南农业大学资源与环境学院,河南郑州450002 [3]天津大学地球系统科学学院表层地球系统科学研究院,天津300072

出　　处：《中国环境科学》2024年第1期288-299,共12页China Environmental Science

基　　金：中央级公益性科研院所基本科研业务费专项(2022YSKY-49);国家自然科学基金资助项目(42107069)。

摘　　要：为定量识别大港河流域硝酸盐来源的贡献,在降水条件下,对秋季(2020年11月)和春季(2021年3月)典型月份在大港河流从上游山林农业区到下游湖滨区共布设8个河水及沉积物监测点,其中包含地下水、生活污水及畜禽粪便、山林农业区和流域土壤等20个硝酸盐氮源监测点,通过大港河水体水化学分析、结合硝酸盐氮氧双同位素示踪技术和贝叶斯混合模型,探究了大港河流域水体硝酸盐来源及迁移转化过程,确定了各硝酸盐源的贡献.结果表明:(1)秋季和春季大港河流域水体中TN浓度均值分别为3.20和3.23mg/L,劣于地表水环境质量Ⅴ类标准,NO_(3)^(-)-N是影响水体水质氮素超标的主要赋存形式;(2)降水的驱动作用影响大港河流域硝酸盐浓度的季节变化,流域氮循环过程以硝化作用为主,多种氮转化过程共同发生;(3)生活污水或畜禽粪便对流域水体的硝酸盐为主要贡献,其贡献率在秋季和春季分别为40.8%±32.8%和55.8%±27.3%,其次是地下水和流域土壤,降水对流域硝酸盐的贡献作用始终最小.To explore the sources and transformation of surface water nitrate in Dagang River Basin,we defined eight sampling points from the upstream to downstream along the Dagang River from which samples of surface water and sediment were collected when precipitation occurred in autumn(November 2020)and spring(March 2021).A total of 20 samples of groundwater,sewage,manure and soils were analyzed with hydrogeochemistry,nitrogen and oxygen isotope tracer technology,and Bayesian mixture model.Results show that:(1)the total nitrogen(TN)concentration of surface water was 3.20mg/L in the autumn and 3.23mg/L in the spring(70.9%in the form of NO_(3)^(-)-N),which was higher than the environmental quality of surface water V standard;(2)nitrogen cycling process in the Dagang River Basin was dominated by nitrification,while precipitation led to the seasonal changes in nitrate concentration;(3)domestic wastewater and livestock manure were two main sources of nitrate to the watershed waters,collectively contributing(40.8%±32.8%)in the autumn and(55.8%±27.3%)in the spring,followed by groundwater and soils,while the least by precipitation.

关 键 词：降水 大港河流域 氮氧双同位素 硝酸盐来源 贝叶斯混合模型 来源解析 

分 类 号：X171[环境科学与工程—环境科学]