对2016年4,6,和8月合肥市塘西河人工湿地水体中的溶解态硝酸盐进行稳定氮同位素分析.通过不同的季节人工湿地内硝酸盐的稳定氮同位素值(δ15N-NO3)的变化情况来研究水体中氮的迁移、转变等生物地球化学过程,从而揭示其环境行为,同时对该人工湿地氮的循环机制进行探究.研究发现:该人工湿地的δ15N-NO3-值分布在13.9‰～22.7‰,表明其硝酸盐氮的主要来源是人畜排泄物或城市生活污水.4,6,8月水体中的δ15N-NO3-值都受硝化、矿化、植物同化作用的影响;6月水体中的δ15N-NO3-值还受藻类同化吸收作用的影响;8月水体中的δ15N-NO3-值还受雨水混合、藻类同化吸收与反硝化作用的影响.%The stable nitrogen isotopic composition of dissolved nitrate in a constructed wetland was studied during April,June and August of 2016 in Hefei.Based on the variations of δ15N-NO3-in different seasons,the biogeochemical processing of nitrogen transformation was studied and its environmental implications were also revealed.The results showed that δ15 N-NO3-values of the constructed wetland distribution were between 13.9‰ ～22.7‰,indicating that the main source of nitrate nitrogen was human and animal excreta or city sewage.δ15 N-NO3-values were affected by the effects of mineralization,nitrification,plant assimilation in April,June and August.In June,δ15 N-NO3-values were affected by algal assimilation effect.In August,δ15N-NO3-values were also affected by rainwater,denitrification effect and algae assimilation.
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