通过一种新型催化臭氧化系统选择性氧化氨到二:通过硫酸盐调节N2选择性
Yuexinxi Wang1, Yong Liu1, Shizong Wang2
1College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, PR China.
Chemosphere
|December 21, 2024
概括
这项研究引入了一种新的UV/O3/MgO/Na2SO3系统,用于选择性- (NH4+-N) 氧化到二 (N2). 该系统避免了有毒的副产品,并实现了高的N2选择性,提供了一个新的水处理策略.
科学领域:
- 环境化学环境化学
- 水处理技术水处理技术
- 先进的氧化过程 先进的氧化过程
背景情况:
- 在水处理中,选择性氧化- (NH4+-N) 到二 (N2) 是一个挑战.
- 使用基激素的传统方法产生有毒的消毒副产品.
- 需要有效和环保的NH4+-N去除策略.
研究的目的:
- 开发一种新型的催化臭氧化系统,用于选择性NH4+-N氧化到N2.
- 调查硫酸 (Na2SO3) 在增强N2选择性的作用.
- 阐明UV/O3/MgO/Na2SO3系统中涉及的反应机制.
主要方法:
- 使用了一种催化臭氧化系统,该系统结合了紫外线照射,臭氧 (O3),氧化 (MgO) 和硫酸 (Na2SO3).
- 该系统在水溶液中测试了NH4+-N的氧化.
- 分析了活性氧物种,中间体和反应机制.
主要成果:
- 紫外线/O3/MgO/Na2SO3系统实现了高N2选择性 (>85%) 的NH4+-N氧化.
- 硫酸 (Na2SO3) 通过在紫外线照射下产生的水合电子将中间物种 (NO2,NO3,NOx) 减少到N2.
- 该系统展示了有效的NH4+-N去除的潜力,而无需基激素.
结论:
- 开发的UV/O3/MgO/Na2SO3系统为选择性NH4+-N氧化到N2.2提供了一个有希望的,无的战略.
- 硫酸通过减少中间体,在提高N2选择性方面发挥着至关重要的作用.
- 这种方法在处理水和废水以去除方面取得了重大进展.
相关概念视频
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
3.7K
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
3.7K
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
3.2K
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...
3.2K
2° Amines to N-Nitrosamines: Reaction with NaNO2
4.0K
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
4.0K
Preparation of Amines: Reduction of Oximes and Nitro Compounds
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Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
3.4K
Diazonium Group Substitution: –OH and –H
2.7K
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
2.7K
Electrophilic Aromatic Substitution: Nitration of Benzene
5.6K
The nitration of benzene is an example of an electrophilic aromatic substitution reaction. It involves the formation of a very powerful electrophile, the nitronium ion, which is linear in shape. The reaction occurs through the interaction of two strong acids, sulfuric and nitric acid.
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