基于同位素示踪方法的东江流域氮素分布特征和来源解析_裴德富.pdf

第 43 卷第 3 期2023 年 3 月Vol.43，No.3Mar.，2023环境科学学报Acta Scientiae Circumstantiae基于同位素示踪方法的东江流域氮素分布特征和来源解析裴德富1，2，徐丽1，赵学敏2，梁荣昌2，姚玲爱2，马千里2，赵瑞2，张水航1，2，苟婷2，*1.沈阳建筑大学市政与环境工程学院，沈阳 1101682.生态环境部华南环境科学研究所（生态环境部生态环境应急研究所），广州 510535摘要：为了探明东江流域氮素污染现状及氮素污染来源，在东江流域设置 31个采样点位，于2020年枯水期（1月）和丰水期（7月）进行水体样品和主要污染源样品的采集及检测，结合氮氧双稳定同位素及SIAR模型，绘制典型污染源的15N、18O特征分布图并估算其贡献率，定量分析识别氮素来源，从而对东江流域的氮负荷进行更加有效地控制.结果表明：东江流域氮素污染以支流区最为严重，其次为源头区，这两个区域的水质均达到地表水环境质量标准（GB3838-2002）氨氮浓度的III类水平，相比之下，上游区、中游区污染较轻，且氨氮浓度能达到地表水环境 质量标准的II类水平.东江流域氮素以硝态氮为主要赋存形态，枯水期、丰水期各研究区域内硝态氮占总氮的比例分别为43.29%74.83%、65.51%80.08%.东江流域枯水期生活污水是主要的污染来源，贡献率为44.45%61.39%，丰水期降雨径流是主要的污染来源，贡献率为36.67%46.11%，究其原因跟流域内不同水文期降雨量大小和河道水量有关.氮素浓度在丰水期和枯水期之间存在明显差异，且从2009年至今，水体氮素污染程度呈现加重趋势，建议通过测土配方，因地制宜地使用化肥、农家肥，将产生的生活污水、养殖废水等收集集中处理等 措施，提高污水处理率，减轻东江流域氮素污染负荷.关键词：东江；氮素；稳定同位素；SIAR模型；时空变化；源解析文章编号：0253-2468（2023）03-0206-10 中图分类号：X522 文献标识码：ACharacterization of nitrogen distribution and source analysis in the Dongjiang River basin based on isotope tracing methodPEI Defu1，2，XU Li1，ZHAO Xuemin2，LIANG Rongchang2，YAO Ling ai2，MA Qianli2，ZHAO Rui2，ZHANG Shuihang1，2，GOU Ting2，*1.School of Municipal and Environmental Engineering，Shenyang University of Architecture，Shenyang 1101682.South China Institute of Environmental Sciences，Ministry of Ecology and Environment（Research Institute of Eco-environmental Emergency，Ministry of Ecology and Environment），Guangzhou 510535Abstract：In order to investigate the status of nitrogen pollution and its sources in the Dongjiang River basin，water samples and major pollution sources samples were collected from 31 sampling sites in the basin during the dry（January）and wet（July）seasons in 2020.Based on the analysis of nitrogen and oxygen dual stable isotope and SIAR models，the characteristic distribution of 15N and 18O of typical pollution sources were mapped and their contribution rates were estimated.The sources of nitrogen pollution were then identified by quantitative analysis，with the aim to more effectively manage and control nitrogen pollution in the Dongjiang River basin.The results showed that：Nitrogen pollution in the Dongjiang River basin was most serious in the tributary area，followed by the source area，though the water quality in these two areas reached the class III level of ammonia nitrogen concentration on basis of the surface water environmental quality standard（GB3838-2002）.The upstream and midstream areas，which were less polluted，could reach the class II level of ammonia nitrogen concentration by the surface water environmental quality standard.Nitrogen in the Dongjiang River basin was dominated by nitrate nitrogen，which accounted for 43.29%74.83%and 65.51%80.08%of the total nitrogen in the study area during the dry and wet seasons，respectively.The pollution was mainly originated from domestic sewage in the Dongjiang River basin during the dry season，with a contribution rate of 44.45%61.39%，while rainfall runoff was the main source of pollution during the wet season，with a contribution rate of 36.67%46.11%.The difference of sources was attributable to precipitation and river flow during different hydrological periods in DOI：10.13671/j.hjkxxb.2022.0254裴德富，徐丽，赵学敏，等.2023.基于同位素示踪方法的东江流域氮素分布特征和来源解析 J.环境科学学报，43（3）：206-215PEI Defu，XU Li，ZHAO Xuemin，et al.2023.Characterization of nitrogen distribution and source analysis in the Dongjiang River basin based on isotope tracing method J.Acta Scientiae Circumstantiae，43（3）：206-215收稿日期：2022-05-22 修回日期：2022-07-14 录用日期：2022-07-15基金项目：广东省重点领域研发计划项目（No.2019B110205004）；国家自然科学基金（No.41977353）；中央级公益性科研院所基本科研业务 专项（No.PM-zx703-202204-075）作者简介：裴德富（1997），男，E-mail：；*责任作者，E-mail：goutingscies.org3 期裴德富等：基于同位素示踪方法的东江流域氮素分布特征和来源解析the basin.There was a significant difference for nitrogen concentration between dry and wet seasons，and until now from 2009，the nitrogen pollution of water bodies showed an aggravating trend.It is recommended to improve the sewage treatment capacity and reduce the nitrogen pollution load in the Dongjiang River basin through measures such as soil testing，using chemical and agricultural fertilizers according to local conditions，and collecting and centralizing the generated domestic sewage and farming wastewater for treatment.Keywords：Dongjiang River；nitrogen；stable isotopes；SIAR model；spatial and temporal variation；source analysis1引言（Introduction）随着工业化进程的加快、经济和人口的快速增长，密集的人类活动导致水体中营养物质浓度不断增加，引起的水体富营养化已成为一个相当普遍且重要的环境问题（Li et al.，2010；庞凤梅等，2011；毛巍等，2013；Li et al.，2013；徐志伟等，2014；张千千等，2015；吴文欢等，2016）.水体一旦富营养化，在适宜的条件下藻类水华随之出现.李艳红等（2021）研究发现，藻类数量与氨氮浓度相关性不显著，与总氮、硝酸盐氮浓度呈显著负相关.治理水体富营养化问题，控制氮素污染是首要解决的难题之一，必须掌握氮素的时空分布特征和主要来源.目前针对氮素的时空分布特征已有大量研究，许多学者研究发现不同时期的环境条件和人类的生产生活活动对于氮素浓度分布的影响尤为显著.孔杰等（2021）研究发现，环境因子会影响氮的硝化、氨化和同化作用，水体氮素的分布和来源受不同时期环境条件变化和生产生活活动的影响；梁爽等（2021）研究发现，氮素浓度呈现春夏高、秋冬低的年内变化特征.可见，不同时期的环境条件变化对氮素浓度的分布会产生较大影响.氮氧双稳定同位素示踪技术是目前应用广泛且准确率较高的氮素源解析的方法（袁洁，2017），并且对 NO3-的转化可进行区分（Yi et al.，2017；Adebowale et al.，2019；Guo et al.，2020）.Bu等（2017）通过对海城河进行15N和18O同位素溯源发现，春季NO3-N源主要由污水/粪便贡献，初夏NO3-N源主要是由合成肥料的硝化过程诱导；Xing等（2016）研究发现，降水、粪肥、污水、土壤有机氮和合成