| 引用本文: | 梁越,肖化云,刘小真,胡倩倩,谢亚军,曹彦圣,丁新航.碳氮稳定同位素示踪鄱阳湖流域蚌湖丰水期的氮污染.湖泊科学,2018,30(4):957-966. DOI:10.18307/2018.0409 |
| LIANG Yue,XIAO Huayun,LIU Xiaozhen,HU Qianqian,XIE Yajun,CAO Yansheng,DING Xinhang.Carbon and nitrogen stable isotopes tracing nitrogen pollution in major flooding season in Lake Bang, Lake Poyang Basin. J. Lake Sci.2018,30(4):957-966. DOI:10.18307/2018.0409 |
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| 碳氮稳定同位素示踪鄱阳湖流域蚌湖丰水期的氮污染 |
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梁越1, 肖化云1, 刘小真2, 胡倩倩1, 谢亚军1, 曹彦圣1, 丁新航1
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1.东华理工大学江西省大气污染成因与控制重点实验室, 核资源与环境国家重点实验室培育基地, 水资源与环境工程学院, 南昌 330013;2.南昌大学资源环境与化工学院, 鄱阳湖环境与资源利用教育部重点实验室, 南昌 330047
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| 摘要: |
| 鄱阳湖边缘深水区是鄱阳湖水位上涨时扩散而成的低洼湖区，通过对其一典型边缘湖泊——蚌湖丰水期的氮浓度和同位素特征值的检测，分析这类洪泛湖泊在水位最高时期水体颗粒有机质及无机氮的氮同位素变化特征，并识别氮污染来源及转化途径.结果表明：6月悬浮颗粒有机质碳氮同位素值（δ13C：-26.7‰~-23.7‰，δ15N：2.6‰~6.2‰）介于土壤有机质（δ13C：-25.21‰±0.52‰，δ15N：3.79‰±0.37‰）和水生植物的碳氮同位素值（δ13C：-28.8‰~-24.9‰，δ15N：5.3‰~8.2‰）之间.7月相比于6月，降低的δ13C（-27.6‰~-23.2‰）和升高的δ15N（4.3‰~7.7‰）表明暴雨冲刷带来更多的周边陆地碎屑输入.无机氮在6月以铵态氮（NH4+-N）为主要形态，7月以硝态氮（NO3--N）为主要形态.6月δ15NH4+较负的特征值（-18.6‰±5.2‰）表明铵态氮主要来源于雨水，硝态氮（δ15NO3-：1.4‰±3.0‰）主要来源于农业化肥和雨水.7月相比于6月，铵态氮和硝态氮的浓度和同位素值都大幅升高（分别升高了0.3和2倍，6‰和3‰），是暴雨冲刷陆地使农业化肥、城镇生活废水和畜禽养殖废水输入的结果.水生植物的δ15N在7月（8.8‰±1.1‰）相比于6月（6.6‰±1.1‰）也升高了较多，是由于水生植物吸收了更高δ15N废水无机氮的结果.通过颗粒有机质和无机氮的δ15N分析可知，湖区水体氮的矿化作用和硝化作用较强，藻类对湖泊的内源氮贡献较弱，沿河湖的畜禽养殖在暴雨时对水域污染的威胁较大.本研究提供了洪泛湖泊氮污染治理的科学依据. |
| 关键词: 碳氮稳定同位素 氮污染 鄱阳湖 蚌湖 丰水期 |
| DOI：10.18307/2018.0409 |
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| 基金项目:国家自然科学基金项目（41563001）、国家重大研究与开发项目（2016YTA0601000）、东华理工大学核资源与环境国家重点实验室培育基地自主基金项目（Z1610）和东华理工大学江西省大气污染成因与控制重点实验室开放基金项目（AE1602，DHBK2015326）联合资助. |
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| Carbon and nitrogen stable isotopes tracing nitrogen pollution in major flooding season in Lake Bang, Lake Poyang Basin |
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LIANG Yue1, XIAO Huayun1, LIU Xiaozhen2, HU Qianqian1, XIE Yajun1, CAO Yansheng1, DING Xinhang1
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1.Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, State Key Laboratory Breeding Base of Nuclear Resources and Environment, School of Water Resources & Environmental Engineering, East China University of Technology, Nanchang 330013, P. R. China;2.Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources Environmental & Chemical Engineering, Nanchang University, Nanchang 330047, P. R. China
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| Abstract: |
| The edge low-lying regions of are deep-water lakes when water levels rise and spread. We analyzed the changing characteristics of nitrogen stable isotope values of the particle organic matter and inorganic nitrogen during major flooding seasons in Bang Lake, one of the edge-lake of, and discriminated the origins and transformations of nitrogen pollution. The results showed that carbon and nitrogen stable isotopes value (δ13C, δ15N) of suspended particle organic matter in June were -26.7‰--23.7‰ and 2.6‰-6.2‰, respectively, which were in the range of those of soil organic matter (-25.21‰±0.52‰ and 3.79‰±0.37‰, respectively) and those of water plant (-28.8‰--24.9‰ and 5.3‰-8.2‰, respectively). The decreasing δ13C(-27.6‰--23.2‰) and the rising δ15N(4.3‰-7.7‰) in July relative to June showed more terrestrial detritus input besides soil organic matter and water plant when rainstorm washes. NH4+-N was main form of inorganic nitrogen in June whereas NO3--N was main form of inorganic nitrogen in July. The more negative δ15NH4+ (-18.6‰±5.2‰) showed ammonia-nitrogen mainly came from rain, and nitrate-nitrogen (δ15NO3-:1.4‰±3.0‰) mainly from agricultural fertilizer and rain. The concentrations and isotopic values of NH4+-N and NO3--N had much more increasing (0.3 and 2 times, 6‰ and 3‰, respectively) in July than June, which were possible from livelihood wastewater and livestock and poultry breeding wastewater under rainstorm washing. δ15N of aquatic plant had more increasing in July (8.8‰±1.1‰) than June (6.6‰±1.1‰) due to aquatic plant absorbing high δ15N of wastewater. The mineralization and nitrification of nitrogen in the lake were strong by δ15N analysis, and alga made little contribution to internal nitrogen sources in flooding seasons. It was great threaten to watersheds pollution to livestock and poultry breeding along the bank of river and lake under rainstorm. This study can help to control nitrogen pollution of flooding lakes. |
| Key words: Carbon and nitrogen stable isotopes nitrogen pollution Lake Poyang Lake Bang flooding season |
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