基于稳定同位素的潇河灌区硝酸盐污染溯源分析  

Source apportionment of nitrate pollution in the Xiaohe River Irrigation Area based on stable isotope

作　　者：孟志龙 刘婷 高玉凤 王捷 张义茹 MENG Zhilong;LIU Ting;GAO Yufeng;WANG Jie;ZHANG Yiru(College of Biological Science and Technology,Taiyuan Normal University,Jinzhong 030619;Shanxi Key Laboratory of Earth Surface Processes and Resource Ecological Security in Fenhe River Basin,Taiyuan Normal University,Jinzhong 030619;Institute of Soil and Water Conservation,Shanxi Agricultural University,Taiyuan 030013)

机构地区：[1]太原师范学院生物科学与技术学院,晋中030619 [2]太原师范学院汾河流域地表过程与资源生态安全山西省重点实验室,晋中030619 [3]山西农业大学水土保持科学研究所,太原030013

出　　处：《环境科学学报》2024年第12期27-36,共10页Acta Scientiae Circumstantiae

基　　金：山西省基础研究计划(自由探索类)项目(No.202103021223325,20210302124022);国家自然科学基金联合基金项目(No.U21A20216)。

摘　　要：为更好地对农灌区氮污染进行防治,本研究以潇河灌区为研究区,于2022年12月—2023年10月对地表水进行采样分析,综合运用水化学分析、氮氧双同位素示踪技术、IsoSource源解析模型,对潇河灌区硝酸盐污染特征及来源进行分析.结果表明:潇河灌区地表水呈弱碱性,优势阳离子和阴离子分别为Mg^(2+)和HCO_(3)^(-),水化学形成受到水岩作用影响显著.硝酸盐含量时间变化显著,2月和10月分别出现最高值和最低值,丰水期和枯水期硝酸盐含量变化无明显差异.硝化作用在流域氮循环中占主导地位,反硝化作用不明显.污水及粪便是潇河灌区主要硝酸盐来源,占比为41%~70%.北合流村(BHL)、张庆乡(ZQ)、张花村(ZH)和南马村(NM)的化肥和土壤有机氮占比较高,分别为20%~29%和31%~52%;湿地公园(SD)和郝村(HC)的污水及粪便贡献率较高,分别为55%和62%;污水及粪便是修文镇(XW)和赵家堡村(ZJB)硝酸盐污染的主要来源,分别约占93%和88%.本研究可为农灌区硝酸盐污染治理及水生态保护提供理论参考.To better prevent and control nitrogen pollution in agricultural irrigation area,this study focused on the Xiaohe Irrigation,analyzing the surface water samples collected from December 2022 to October 2023.The characteristics and sources of nitrate pollution in the Xiaohe Irrigation Area were investigated using a combination of hydrochemical analysis,nitrogen and oxygen mult-isotope tracer and IsoSource analysis model.The results revealed that the surface water in the Xiaohe Irrigation area was weakly alkaline,with dominant cations and anions beijing Mg^(2+) and HCO_(3)^(-) respectively.Hydrochemical formation were significantly affected by rock weathering.The highest contents of nitrate were appeared in February,and lowest in October.There was no significant difference in nitrate content between the wet and dry seasons.Nitrification plays a dominant role in the nitrogen cycle in the study area,while denitrification was not significant.Sewage and manure were the main nitrate sources in the Xiaohe Irrigation Area,accounting for 41%~70%of the total.Fertilizer and soil organic nitrogen contributed more significantly at specific sites,including BHL,ZQ,ZH and NM,accounting for 20%~29%and 31%~52%,respectively.The contribution rates of sewage and manure were 55%and 62%in the sampling sites of SD and HC respectively.Sewage and manure were the main sources of nitrate in the sampling sites of XW and ZJB,accounting for about 93%and 88%respectively.This study provides valuable theoretical insights for nitrate pollution control and water ecological protection in agricultural irrigation areas.

关 键 词：潇河灌区 氮氧同位素 硝酸盐污染 溯源分析 

分 类 号：X522[环境科学与工程—环境工程]