太湖上游丘陵区典型水塘反硝化潜力变化特征及其影响因素  

Variation characteristics and influential factors of denitrification potential of typical ponds in the hilly region of the upper Lake Taihu Basin

作　　者：王慧亮[1] 曹恒 张汪寿 李恒鹏[2] 何鹏[1] 夏天宇 陈永娟 Wang Huiliang;Cao Heng;Zhang Wangshou;Li Hengpeng;He Peng;Xia Tianyu;Chen Yongjuan(School of Water Conservancy Engineering,Zhengzhou University,Zhengzhou 450001,P.R.China;Key Laboratory of Watershed Geographic Science,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,P.R.China;College of Civil and Architeture Engineering,Chuzhou University,Chuzhou 239099,P.R.China)

机构地区：[1]郑州大学水利科学与工程学院,郑州450001 [2]中国科学院南京地理与湖泊研究所,中国科学院流域地理学重点实验室,南京210008 [3]滁州学院土木与建筑工程学院,滁州239099

出　　处：《湖泊科学》2022年第6期1937-1948,共12页Journal of Lake Sciences

基　　金：国家重点研发计划项目(2018YFD1100102);国家自然科学基金项目(42071143,41877513)联合资助。

摘　　要：水塘是连接上游集水坡地和下游水体的重要水文通道,也是氮素发生生物地球反应的重要场所.作为氮素高效去除的首要机制,水塘的反硝化脱氮潜力及其影响因素亟待揭示.本研究选择太湖上游丘陵区天目湖流域4类(茶园塘、村塘、养殖塘、林塘)共14个典型水塘为研究区,分别监测了其夏、秋季水质和沉积物变化特征,并利用膜进样质谱法(MIMS)直接测定水塘水体中溶存的反硝化产物N浓度.结果发现,14个水塘上覆水中N过饱和浓度在1.36~28.35μmol/L之间,平均值为(8.23±6.04)μmol/L,夏季和秋季N过饱和浓度分别为(8.81±4.08)和(7.64±7.46)μmol/L,夏季高于秋季,不同类型水塘N2过饱和浓度大小顺序为:茶园塘>村塘>养殖塘>林塘;结合水气交换通量模型估算了反硝化潜力,14个水塘的反硝化速率均值为(4.75±3.27)mmol/(m^(2)·d),反硝化速率大小顺序为:茶园塘>村塘>养殖塘>林塘.相关分析结果表明,反硝化作用与水体中硝态氮浓度呈显著正相关,与溶解氧浓度呈显著负相关;反硝化作用同样与沉积物中硝态氮含量呈显著正相关,与容重呈负相关,说明水塘反硝化作用同时受上覆水中硝态氮、溶解氧以及沉积物容重等理化性质共同调节.进一步通过与传统的反硝化测算方法对比验证,发现采用膜进样质谱法并结合水气交换通量模型来估算水体反硝化潜力具有可行性,同时操作简便、所需样品少、测定速度快,适用于淹水环境反硝化作用的测定.The ponds are important hydrological channels connecting the upstream hillslope and the downstream water bodies,and important hotspots for nitrogen processing.As the primary mechanism of efficient nitrogen removal,the potential of denitrification and nitrogen removal in ponds and its influential factors were rarely been documented.In this study,fourteen typical ponds of four types(tea garden pond,village pond,fish pond,and forested pond) in Lake Tianmu Basin in the hilly region of the upper reaches of Lake Taihu were selected as our study sites.The characteristics of water quality and sediment change in summer and autumn were monitored respectively,and the levels of dissolved denitrifying product-Nin the ponds were directly determined by membrane injection mass spectrometry(MIMS).The results showed that Nsupersaturated concentration in the overlying water of 14 ponds ranged from 1.36 μmol/L to 28.35 μmol/L,with an average of(8.23 ± 6.04) μmol/L.Nsupersaturated concentration was(8.81±4.08) μmol/L in summer and(7.64±7.46) μmol/L in autumn,and the concentration of Nsupersaturated in different ponds in summer is higher than that in autumn.The ΔN2was the highest in tea garden ponds,followed by village ponds and fish ponds,and the lowest in forested ponds.The mean value of denitrification rates of 14 ponds was(4.75±3.27) mmol/(m^(2)·d),which was highest in tea garden ponds,followed by village ponds and fish ponds,and lowest in forested ponds.Correlation analysis showed that denitrification was significantly positively correlated with nitrate concentration,and significantly negatively correlated with dissolved oxygen.Denitrification was also significantly positively correlated with nitrate concentration in sediment,and negatively correlated with bulk density,indicating that denitrification in ponds was simultaneously regulated by substrate concentration,dissolved oxygen concentration,and sediment physical and chemical properties.Compared and validated with the traditional denitrification measurement method,th

关 键 词：天目湖流域 丘陵区水塘 膜进样质谱法 水气通量 反硝化 

分 类 号：P342[天文地球—水文科学] X143[天文地球—地球物理学]