概括
湖泊239号 湖泊239号 湖泊239号
科学领域:
- 环境化学环境化学
- 临界技术 临界技术
- 生物地质化学生物地质化学
背景情况:
- 酸沉积对水生生态系统产生影响.
- 了解性生成对于生态系统健康至关重要.
- 实验湖区的湖239提供了一个案例研究.
研究的目的:
- 为239湖及其周围的流域构建详细的度预算.
- 确定性产生的主要来源和过程.
- 为了比较水生和陆生性生成率.
主要方法:
- 湖泊及其陆地流域的细节度预算构造.
- 离子预算分析以确定性生产途径.
- 与实验性酸化湖223的数据进行比较.
主要成果:
- 239号湖的度是其陆地盆地度的4.5倍.
- 生物过程,特别是硫酸盐的减少,是湖中的性的主要来源.
- 一个陆地流域是一个重要的性来源,另一个产量很少,湿地流域是一个水槽.
- 通过硫酸还原的性生产增加了硫酸输入.
结论:
- 生物过程在湖泊性生成中所扮演的角色比以前所认为的更为重要.
- 陆地流域对性的贡献可以显著变化.
- 湖泊的性动态对酸性输入敏感,而硫酸盐的减少是一个关键的响应过程.
相关概念视频
Acids, Bases and Neutralization Reactions
An acid-base reaction is one in which a hydrogen ion, H+, is transferred from one chemical species to another. Such reactions are of central importance to numerous natural and technological processes, ranging from the chemical transformations within cells or lakes and oceans to the industrial-scale production of fertilizers, pharmaceuticals, and other substances essential to the society.
Buffers
A solution containing appreciable amounts of a weak conjugate acid-base pair is called a buffer solution, or a buffer. Buffer solutions resist a change in pH when small amounts of a strong acid or a strong base are added. A solution of acetic acid and sodium acetate is an example of a buffer that consists of a weak acid and its salt: CH3COOH (aq) + CH3COONa (aq). An example of a buffer that consists of a weak base and its salt is a solution of ammonia and ammonium chloride: NH3 (aq) + NH4Cl...
Acids, Bases and Neutralization Reactions
Acids and bases play several important roles in biology. The pH of a biological system can significantly impact the function of biological molecules, including enzymes, proteins, and nucleic acids. For example, enzymes have optimal pH ranges for their activity, and changes in pH can denature or alter their structure, affecting their function. Acids and bases also play a crucial role in cellular signaling and communication. The pH of the extracellular fluid around cells can influence the...
Titration of a Weak Base with a Strong Acid
The titration curve of a weak base like ammonia with a strong acid like hydrochloric acid is the mirror image of the titration curve of a weak acid with a strong base.
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
Buffers: Overview
Buffers play a crucial role in stabilizing the pH of a solution by mitigating the effects of small amounts of added acid or base. They consist of a weak acid and its conjugate base or a weak base and its conjugate acid. A solution of acetic acid and sodium acetate is an example of a buffer that consists of a weak acid and its salt: CH3COOH (aq) + CH3COONa (aq). An example of a buffer that consists of a weak base and its salt is a solution of ammonia and ammonium chloride: NH3 (aq) + NH4Cl (aq).
Freshwater Microbial Ecology
Freshwater systems such as streams, rivers, and lakes exhibit distinct physical and biological characteristics that influence their microbial communities. These environments are broadly categorized into lotic systems—those with flowing waters like streams and most rivers—and lentic systems, which include still or slow-moving waters such as lakes, ponds, and marshes.In lentic systems, phytoplankton drive primary production, generating autochthonous organic carbon. In contrast, lotic systems...


