Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of Nitrate
Acid rain with a relatively high concentration of ammonium and nitrate can accelerate rock weathering. However, its impact on groundwater nitrate is uncertain. This study evaluated the dual isotopic composition of nitrate (δ15N-NO3- and δ18O-NO3-) from precipitation to groundwater in a rural mountai...
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| Language: | English |
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Wiley
2019-01-01
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| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2019/8964182 |
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| author | Tianming Huang Zhenbin Li Baoqiang Ma Yin Long |
| author_facet | Tianming Huang Zhenbin Li Baoqiang Ma Yin Long |
| author_sort | Tianming Huang |
| collection | DOAJ |
| description | Acid rain with a relatively high concentration of ammonium and nitrate can accelerate rock weathering. However, its impact on groundwater nitrate is uncertain. This study evaluated the dual isotopic composition of nitrate (δ15N-NO3- and δ18O-NO3-) from precipitation to groundwater in a rural mountainous area affected by acid rain. The average concentration for NH4+ is 1.25 mg/L and NO3- is 2.59 mg/L of acid rain. Groundwater NO3- concentrations ranged from <0.05 to 11.8 mg/L (baseline), and NH4+ concentrations ranged from 0.06 to 0.28 mg/L. The results show that groundwater δ18O-NO3- values (-4.7‰ to +4.2‰) were lower than the values of rainfall δ18O-NO3- (+24.9‰ to +67.3‰), suggesting that rainfall NO3- contributes little to groundwater NO3-. Groundwater δ15N-NO3- values (+0.1‰ to +7.5‰) were higher than the values of δ15N-NO3- derived from the nitrification of rainfall NH4+ (less than -4.7‰ in the study area), suggesting that nitrification of rainfall NH4+ also contributes little to groundwater NO3-. This implies that rainfall NO3- and NH4+ have been utilized. The dual isotopic composition of nitrate shows that baseline groundwater NO3- is derived mainly from nitrification of soil nitrogen. The denitrification process is limited in the groundwater system. This study shows that the rainfall NO3- and NH4+ contribute little to groundwater NO3-, improving the understanding of the nitrogen cycle in areas with a high concentration of NH4+ and NO3- in rainfall. |
| format | Article |
| id | doaj-art-324b84c5ff0340459039605e990c4604 |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2019-01-01 |
| publisher | Wiley |
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| series | Geofluids |
| spelling | doaj-art-324b84c5ff0340459039605e990c46042025-02-03T01:31:14ZengWileyGeofluids1468-81151468-81232019-01-01201910.1155/2019/89641828964182Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of NitrateTianming Huang0Zhenbin Li1Baoqiang Ma2Yin Long3Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, ChinaKey Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, ChinaKey Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, ChinaKey Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, ChinaAcid rain with a relatively high concentration of ammonium and nitrate can accelerate rock weathering. However, its impact on groundwater nitrate is uncertain. This study evaluated the dual isotopic composition of nitrate (δ15N-NO3- and δ18O-NO3-) from precipitation to groundwater in a rural mountainous area affected by acid rain. The average concentration for NH4+ is 1.25 mg/L and NO3- is 2.59 mg/L of acid rain. Groundwater NO3- concentrations ranged from <0.05 to 11.8 mg/L (baseline), and NH4+ concentrations ranged from 0.06 to 0.28 mg/L. The results show that groundwater δ18O-NO3- values (-4.7‰ to +4.2‰) were lower than the values of rainfall δ18O-NO3- (+24.9‰ to +67.3‰), suggesting that rainfall NO3- contributes little to groundwater NO3-. Groundwater δ15N-NO3- values (+0.1‰ to +7.5‰) were higher than the values of δ15N-NO3- derived from the nitrification of rainfall NH4+ (less than -4.7‰ in the study area), suggesting that nitrification of rainfall NH4+ also contributes little to groundwater NO3-. This implies that rainfall NO3- and NH4+ have been utilized. The dual isotopic composition of nitrate shows that baseline groundwater NO3- is derived mainly from nitrification of soil nitrogen. The denitrification process is limited in the groundwater system. This study shows that the rainfall NO3- and NH4+ contribute little to groundwater NO3-, improving the understanding of the nitrogen cycle in areas with a high concentration of NH4+ and NO3- in rainfall.http://dx.doi.org/10.1155/2019/8964182 |
| spellingShingle | Tianming Huang Zhenbin Li Baoqiang Ma Yin Long Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of Nitrate Geofluids |
| title | Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of Nitrate |
| title_full | Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of Nitrate |
| title_fullStr | Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of Nitrate |
| title_full_unstemmed | Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of Nitrate |
| title_short | Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of Nitrate |
| title_sort | tracing the origin of groundwater nitrate in an area affected by acid rain using dual isotopic composition of nitrate |
| url | http://dx.doi.org/10.1155/2019/8964182 |
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