| 摘要: |
| 地下水硝酸盐（NO3-）污染是一个全球性的环境问题，尤其在农业区普遍存在。地下水中NO3-可以通过交互作用进入地表水中，是地表水NO3-的潜在来源。研究地下水中NO3-的来源及其贡献率对防治周边地表水NO3-污染具有重要意义。本研究以四川盆地农业区河流型水库周边地下水为研究对象，综合运用水文地球化学、多种稳定同位素（δD-H2O和δ18O-H2O，δ15N-NO3-和δ18O-NO3-）、贝叶斯同位素混合模型（SIAR）和人类健康风险评价（HHRA）解析地下水中NO3-的来源与转化过程、不同来源NO3-的贡献率、及潜在的人类健康风险。结果表明：丰、枯水期地下水中NO3--N的浓度分别为1.24~42.91 mg/L和0~42.96 mg/L，61%和40%的地下水样品超过了饮用水限值（10 mg/L）。δ15N-NO3-和δ18O-NO3-表明研究区地下水中NO3-的主要来源为粪肥/生活污水。硝化作用可能是研究区地下水中重要的氮循环过程，存在加剧地下水NO3-污染的风险。SIAR模型得出丰、枯水期地下水中NO3-的主要来源为粪肥/生活污水，贡献率分别为50%和38%。人类健康风险评价（HHRA）表明长期饮用研究区NO3-浓度较高的地下水对人类健康具有潜在风险。 |
| 关键词: 地下水 硝酸盐 氮氧同位素 SIAR同位素模型 健康风险评估 |
| DOI： |
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| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Origin and health risks of nitrate in groundwater from a riverine reservoir within an agricultural region of the Sichuan Basin |
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He Kexin,Xu Fen,Zhou Yaqian,Qin Jie,Wu lishan,He Xiaoxia,Wang Hong,Yang Rui
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Chengdu University Of Technology
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| Abstract: |
| Groundwater nitrate pollution (NO3-) is a global environmental concern, particularly prevalent in agricultural areas. The presence of NO3- in groundwater can potentially contaminate surface water bodies, thereby serving as a significant source of NO3- contamination. Therefore, comprehending the origin and contribution rate of NO3- in groundwater is imperative for effective prevention and control measures against nearby surface water pollution. The present study employed hydrogeochemistry, stable isotopes (δD-H2O and δ18O-H2O, δ15N-NO3- and δ18O-NO3-) in conjunction with the Bayesian isotope mixing model (SIAR), and the Human Health Risk Assessment (HHRA) to comprehensively analyze the sources of NO3- and their contribution rates, as well as potential risks to human health in groundwater surrounding a riverine reservoir located in the agricultural region of the Sichuan Basin. The results observed that 61% and 40% of groundwater samples exceeded the drinking water guideline (10 mg/L), with NO3--N concentrations in groundwater ranging from 1.24 to 42.91 mg/L and 0 to 42.96 mg/L during the high and low water periods, respectively. The isotopic compositions of δ15N-NO3- and δ18O-NO3- indicated that manure/domestic wastewater were identified as the primary sources of NO3- in the study area. Nitrification was found to be a significant nitrogen cycling process in the groundwater of this region, potentially exacerbating current levels of NO3- pollution. The SIAR model revealed that manure/domestic wastewater contributed approximately 50% and 38% of total NO3- content in the groundwater during the high and low water periods, respectively. Furthermore, based on the Human Health Risk Assessment (HHRA), oral consumption of groundwater containing high concentrations of NO3- may pose potential health risks to individuals residing within this study area. |
| Key words: Groundwater Nitrate δ15N-NO3-and δ18O-NO3- SIAR stable isotopes model Health risk assessment |
