基于氮氧同位素示踪技术解析汾河中游雨季硝酸盐污染源  

Using Isotopes of Nitrogen and Oxygen to Analysis of Surface Water Nitrate Sources in the Rainy Season of the Middle Fenhe River

作　　者：赵宇航 胡雪纯 解文艳 刘志平 杨振兴 周怀平 Zhao Yuhang;Hu Xuechun;Xie Wenyan;Liu Zhiping;Yang Zhenxing;Zhou Huaiping(College of Resources and Environment,Shanxi Agricultural University,Taiyuan,Shanxi 030031,China)

机构地区：[1]山西农业大学资源环境学院,山西太原030031

出　　处：《山西水土保持科技》2023年第2期50-56,共7页Soil and Water Conservation Science and Technology in Shanxi

基　　金：山西省水利科学技术研究与推广项目(2022GM043);山西省基础研究计划项目(202103021224124)。

摘　　要：运用水化学分析、氮氧双稳定同位素示踪及IsoSource混合模型计算等方法,定量识别汾河中游流域雨季地表水硝酸盐污染源的贡献率。结果表明:①汾河中游地表水各形态氮浓度具有较强的空间变异性。汾河中游干流地表水总氮(TN)、硝态氮(NO_(3)^(-)-N)、铵态氮(NH_(4)^(+)-N)和亚硝态氮(NO_(2)^(-)-N)的平均浓度(12.32、5.22、0.87和0.86 mg/L)高于东岸支流(8.79、1.56、0.28和0.21 mg/L)和西岸支流(10.82、2.46、0.59和0.39 mg/L)。汾河中游地表水总氮的输出形式主要以NO_(3)^(-)-N为主。②δ^(15)N-NO_(3)^(-)和δ^(18)O-NO_(3)^(-)含量变化范围为-3.10‰~23.91‰(平均值9.74‰)和-7.64‰~7.75‰(平均值-0.67‰)。粪便和污水、土壤有机氮和农业化肥是汾河中游地表水NO_(3)^(-)的主要来源。③IsoSource混合模型计算表明,汾河中游干流土壤有机氮、粪便和污水、农业化肥对地表水硝酸盐污染贡献比例分别为17.1%、77.1%和5.8%,东岸支流硝酸盐各污染来源的贡献比例为21.0%、65.4%和13.6%,西岸支流硝酸盐各污染来源的贡献比例为27.5%、59.8%和12.7%。因此,减少生活污水和人畜粪便的排放,提高氮肥利用率是改善汾河中游流域水质的有效措施。Water chemical analysis,nitrogen and oxygen bistable isotope tracer and IsoSource mixed model were used to identify the contribution rate of nitrate pollution sources to surface water in the middle reaches of Fenhe River during rainy season.The results showed that:(1)The nitrogen concentration of various forms in the middle reaches of Fenhe River had strong spatial variability.The average concentrations of total nitrogen(TN),nitrate nitrogen(NO_(3)^(-)-N),ammonium nitrogen(NH_(4)^(+)-N)and nitrous nitrogen(NO_(2)^(-)-N)in surface water of the middle stream of Fenhe River(12.32,5.22,0.87 and 0.86 mg/L)were higher than those of the tributaries on the east coast(8.79,1.56,0.28 and 0.21)mg/L)and west coast tributaries(10.82,2.46,0.59 and 0.39 mg/L).The output form of total nitrogen in surface water in the middle reaches of Fenhe River was mainly NO_(3)^(-)-N.(2)The content range ofδ^(15)N-NO_(3)^(-)andδ^(18)O-NO_(3)^(-)were 3.10‰~23.91‰(average 9.74‰)and 7.64‰~7.75‰(average-0.67‰).Manure and sewage,soil organic nitrogen and agricultural fertilizer were the main sources of NO_(3)^(-)in surface water in the middle reaches of Fenhe River.(3)The IsoSource mixing model showed that the contributions of soil organic nitrogen,manure,sewage and agricultural fertilizer to surface water nitrate pollution in surface water of the middle stream of Fenhe River were 17.1%,77.1%and 5.8%,respectively,and that of nitrate pollution sources in the east coast tributary were 21.0%,65.4%and 13.6%,and that of nitrate pollution sources in the west coast tributary were 27.5%,59.8%and 12.7%.Therefore,reducing the discharge of domestic sewage and human and animal manure and increasing the utilization rate of nitrogen fertilizer were effective measures to improve the water quality in the middle reaches of Fenhe River.

关 键 词：硝酸盐 氮氧同位素 污染源 溯源分析 汾河中游 

分 类 号：X52[环境科学与工程—环境工程]