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Bao Y, Sun M, Wang Y, Hu M, Hu P, Wu L, Huang W, Li S, Wen J, Wang Z, Zhang Q, Wu N. Nitrate transformation and source tracking of Yarlung Tsangpo River using a multi-tracer approach combined with Bayesian stable isotope mixing model. ENVIRONMENTAL RESEARCH 2024; 252:118925. [PMID: 38615795 DOI: 10.1016/j.envres.2024.118925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 04/01/2024] [Accepted: 04/11/2024] [Indexed: 04/16/2024]
Abstract
Excessive levels of nitrate nitrogen (NO3--N) could lead to ecological issues, particularly in the Yarlung Tsangpo River (YTR) region located on the Qinghai Tibet Plateau. Therefore, it is crucial to understand the fate and sources of nitrogen to facilitate pollution mitigation efforts. Herein, multiple isotopes and source resolution models were applied to analyze key transformation processes and quantify the sources of NO3-. The δ15N-NO3- and δ18O-NO3- isotopic compositions in the YTR varied between 1.23‰ and 13.64‰ and -7.88‰-11.19‰, respectively. The NO3--N concentrations varied from 0.08 to 0.86 mg/L in the dry season and 0.20-1.19 mg/L during the wet season. Nitrification remained the primary process for nitrogen transformation in both seasons. However, the wet season had a widespread effect on increasing nitrate levels, while denitrification had a limited ability to reduce nitrate. The elevated nitrate concentrations during the flood season were caused by increased release of NO3- from manure & sewage (M&S) and chemical fertilizers (CF). Future endeavors should prioritize enhancing management strategies to improve the utilization efficiency of CF and hinder the direct entry of untreated sewage into the water system.
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Affiliation(s)
- Yufei Bao
- State Key Laboratory of Watershed Water Cycle Simulation and Regulation, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China.
| | - Meng Sun
- State Key Laboratory of Watershed Water Cycle Simulation and Regulation, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China
| | - Yuchun Wang
- State Key Laboratory of Watershed Water Cycle Simulation and Regulation, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China.
| | - Mingming Hu
- State Key Laboratory of Watershed Water Cycle Simulation and Regulation, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China
| | - Peng Hu
- State Key Laboratory of Watershed Water Cycle Simulation and Regulation, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China
| | - Leixiang Wu
- State Key Laboratory of Watershed Water Cycle Simulation and Regulation, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China
| | - Wei Huang
- State Key Laboratory of Watershed Water Cycle Simulation and Regulation, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China
| | - Shanze Li
- State Key Laboratory of Watershed Water Cycle Simulation and Regulation, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China
| | - Jie Wen
- State Key Laboratory of Watershed Water Cycle Simulation and Regulation, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China
| | - ZhongJun Wang
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China
| | - Qian Zhang
- School of Civil Engineering & Architecture, Wuhan University of Technology, Wuhan, 430070, China
| | - Nanping Wu
- School of Civil Engineering & Architecture, Wuhan University of Technology, Wuhan, 430070, China
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Wang B, Moynier F, Hu Y. Rubidium isotopic compositions of angrites controlled by extensive evaporation and partial recondensation. Proc Natl Acad Sci U S A 2024; 121:e2311402121. [PMID: 38147555 PMCID: PMC10769822 DOI: 10.1073/pnas.2311402121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 11/29/2023] [Indexed: 12/28/2023] Open
Abstract
The planetesimals in the solar system exhibit varying degrees of moderately volatile elements (MVEs) depletion compared to the protosolar composition. Revealing the relevant mechanisms is crucial for exploring early solar system evolution. Most volatile-depleted materials in the solar system exhibit enrichments in the heavier isotopes of MVEs, which have traditionally been attributed to the loss of volatiles through partial evaporation. Angrites are so far an exception as they are enriched in the lighter isotopes of K. This has been interpreted as reflecting condensation processes. Here, we present Rb isotopic data of angrites and find that they have lighter Rb isotopic compositions than Vesta, Mars, and the Moon. The δ87Rb value of the angrite parent body (APB) is estimated to range between -1.19‰ and -0.67‰. The extremely light Rb isotopic composition of the APB is likely a result of the kinetic recondensation of Rb after near-complete evaporation during the magma ocean stage. This finding provides further support for the partial recondensation model to explain the light Rb and K isotopic compositions of the APB. In addition, the APB, alongside other terrestrial planetary bodies (e.g., Earth, Mars, Moon, and Vesta), exhibit a strong correlation between their Rb and K isotopic compositions. This coupling of Rb and K isotopes is indicative of a volatility-driven isotopic fractionation rather than nucleosynthetic anomalies. The extremely light Rb-K isotopic signatures of the APB suggest that beyond evaporation, condensation plays an equally significant role in shaping the planetary-scale distributions of volatile elements.
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Affiliation(s)
- Baoliang Wang
- Institut de Physique du Globe de Paris, Université Paris Cité, CNRS, Paris75005, France
| | - Frederic Moynier
- Institut de Physique du Globe de Paris, Université Paris Cité, CNRS, Paris75005, France
| | - Yan Hu
- Institut de Physique du Globe de Paris, Université Paris Cité, CNRS, Paris75005, France
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