{"title":"Multiple Isotopes Reveal the Nitrate Sources in Aojiang River Basin, Eastern China.","authors":"Jiangnan Li, Qianhang Sun, Kun Lei","doi":"10.1007/s00128-025-04026-9","DOIUrl":null,"url":null,"abstract":"<p><p>Excessive nitrate (NO<sub>3</sub><sup>-</sup>) in water poses a global environmental challenge. Identifying NO<sub>3</sub><sup>-</sup> sources and their contributions is crucial for improving water quality. We collected surface water samples in the Aojiang River basin, Eastern China, during dry and wet seasons. Hydrochemical indicators, δ<sup>15</sup>N-NO<sub>3</sub><sup>-</sup> and δ<sup>18</sup>O-NO<sub>3</sub><sup>-</sup> were used to identify NO<sub>3</sub><sup>-</sup> sources and assess their contributions. The findings revealed nitrification as the primary nitrogen transformation process. Isotopic analysis identified manure and sewage (M&S), soil nitrogen (SN), and nitrogen fertilizer (NF) as major NO<sub>3</sub><sup>-</sup> contributors. The MixSIAR model analysis showed proportional contributions of atmospheric deposition (AD), NF, M&S, and SN to NO<sub>3</sub><sup>-</sup> during the dry season as 2.84%, 19.63%, 44.67%, and 34.87%, respectively. In the wet season, the contributions were 3.61%, 22.32%, 32.37%, and 41.70%, respectively. This study enhances understanding of nitrogen sources and transformations in the Aojiang River basin, aiding better nitrogen contamination management.</p>","PeriodicalId":501,"journal":{"name":"Bulletin of Environmental Contamination and Toxicology","volume":"114 4","pages":"53"},"PeriodicalIF":2.7000,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of Environmental Contamination and Toxicology","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1007/s00128-025-04026-9","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Excessive nitrate (NO3-) in water poses a global environmental challenge. Identifying NO3- sources and their contributions is crucial for improving water quality. We collected surface water samples in the Aojiang River basin, Eastern China, during dry and wet seasons. Hydrochemical indicators, δ15N-NO3- and δ18O-NO3- were used to identify NO3- sources and assess their contributions. The findings revealed nitrification as the primary nitrogen transformation process. Isotopic analysis identified manure and sewage (M&S), soil nitrogen (SN), and nitrogen fertilizer (NF) as major NO3- contributors. The MixSIAR model analysis showed proportional contributions of atmospheric deposition (AD), NF, M&S, and SN to NO3- during the dry season as 2.84%, 19.63%, 44.67%, and 34.87%, respectively. In the wet season, the contributions were 3.61%, 22.32%, 32.37%, and 41.70%, respectively. This study enhances understanding of nitrogen sources and transformations in the Aojiang River basin, aiding better nitrogen contamination management.
期刊介绍:
The Bulletin of Environmental Contamination and Toxicology(BECT) is a peer-reviewed journal that offers rapid review and publication. Accepted submissions will be presented as clear, concise reports of current research for a readership concerned with environmental contamination and toxicology. Scientific quality and clarity are paramount.