溶解有机物质的组成决定了它对湖泊内完全和部分光氧化的敏感性
Reid P Milstead1, Emma R Horvath2, Christina K Remucal1,2
1Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
Environmental science & technology
|July 31, 2023
概括
溶解有机物 (DOM) 在地表水中经历部分光氧化,改变其分子结构. 该研究将DOM成分与其对光诱导变化的易感性联系起来,影响水生碳循环.
科学领域:
- 环境化学环境化学
- 水生化学 水生化学
- 生物地质化学生物地质化学
背景情况:
- 溶解有机物 (DOM) 对于内陆水域的碳循环至关重要.
- 阳光导致DOM光氧化,产生二氧化碳 (CO2) 并改变DOM的组成.
- 了解DOM组合在光氧化易感性中的作用是有限的.
研究的目的:
- 研究DOM分子组成及其对部分和完全光氧化的易感性之间的关系.
- 研究DOM光氧化如何影响地表水中的碳循环.
主要方法:
- 在DOM分离物和湖水样本上进行了暴露于光线的实验.
- 使用高分辨率质谱分析DOM分子组成.
- 测量氧气消耗和溶解无机碳 (DIC) 生产量化的光氧化程度.
主要成果:
- 在所有DOM样本中都发生了广泛的部分光氧化,由高氧消耗与DIC生产比率表明.
- 更多的氧化,芳香DOM配方与增加的氧气消耗和DIC生产相关.
- 部分光氧化导致DOM的芳香度较低,表面分子量较低,涉及氧气添加和二氧化碳损失.
- 最容易受到光氧化的特定DOM配方因DOM初始成分而有所不同.
结论:
- DOM光氧化与其分子组成密切相关.
- 最初的DOM特征决定了特定分子配方对光氧化的易感性.
- 这些发现增强了我们对DOM光氧化及其对水生碳循环的影响的理解.
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