相关实验视频

Updated: Jul 11, 2025

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx

Published on: December 20, 2016

估计大气中沉积在一个大河流域使用的和同位素签名的大气中沉积

Chenjun Du¹, Qingjun Guo², Pengcheng Wu³

¹Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.

|November 5, 2023

概括

在长江流域,形揭示了 (N) 沉积模式. 燃烧源对和酸盐沉积有很大影响,城市排放量增加.

科学领域:

环境科学环境科学
生物地质化学生物地质化学
大气化学大气化学

背景情况:

在高空间分辨率下评估大气 (N) 沉积流和来源是一项挑战.
脊髓性作为一种敏感的生物监测器,监测沉积.
了解沉积对于生态系统健康和环境管理至关重要.

研究的目的:

分析 (NH4+) 和 (NO3-) 沉积在长江流域的流量和主要来源贡献.
为了研究N沉积的空间变化,使用发性的N和delta15N特征.
从2006年到2019年,确定N沉积源的时间趋势.

主要方法:

横跨长江流域的密集的形样本收集.
在组织中分析 (N) 和稳定同位素 (delta15N) 标志.
建模以估计来自不同来源 (挥发,燃烧,化石燃料) 的N沉积流量和分配贡献.

主要成果:

观察到沉积的空间梯度 (9.6-34.0 kg ha-1 yr-1),在耕地和城市地区的度更高.
氨 (NH4+) 沉积量大约是酸盐 (NO3-) 沉积量的三倍.
与传统观点相反,燃烧源 (66.72%) 是NH4+沉积的较大贡献者,而不是挥发 (33.28%).
化石燃料燃烧占NO3沉积的占主导地位 (70.22%).
城市NH3挥发和化石燃料衍生的NOx排放在2006年至2019年之间增加.

结论:

燃烧源是长江流域沉积的关键驱动因素.
形可以有效地监测N沉积的空间和时间变化.
这些发现挑战了关于NH3排放来源的传统假设,并突出了城市排放日益增长的影响.

关键词:

生物监测器是生物监测器.长期生长的摩 (Epilithic moss) 是一种长期生长的质量平衡混合模型的混合模型.的沉积沉积的沉积.来源贡献来源贡献

更多相关视频

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Published on: December 6, 2018

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Published on: October 7, 2020

相关概念视频

Overview of Nitrogen Metabolism

Overview of Nitrogen Metabolism

Nitrogen is a very important element for life because it is a major constituent of proteins and nucleic acids. It is a macronutrient, and in nature, it is recycled from organic compounds and stored in the form of ammonia, ammonium ions, nitrate, nitrite, or nitrogen gas by many metabolic processes. Many of these metabolic processes are carried out only by prokaryotes.
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...

The Nitrogen Cycle

The Nitrogen Cycle

Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...

Inorganic Nitrogen Assimilation

Inorganic Nitrogen Assimilation

Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme...

Precipitation Gravimetry

Precipitation Gravimetry

Precipitation gravimetry is based on converting an analyte into a sparingly soluble precipitate, which is separated by filtration and weighed. An ideal precipitate should be pure, insoluble, of known composition, and easily filtered from the reaction mixture.
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...