Coexisting Anilines Accelerate the Oxidation of Phenolics by Manganese Oxides

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research Pub Date : 2025-05-08 DOI:10.1016/j.watres.2025.123784

Lei Cui , Yingxu Gong , Shengxin Zhao , Jimin Shen , Zhonglin Chen

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Abstract

This work discovered that various anilines could accelerate the oxidation of phenolics by permanganate (Mn^VIIO₄⁻) or birnessite (δ-MnO₂) under ambient conditions. Taking phenol as a probe compound, the coexisting anilines increased the apparent kinetic constants of phenol oxidation by 1.73–18.14 times, that depends on the substituted groups on the anilines and pH conditions. Besides, taking 4-hydroxybenzoic acid (4-HBA) as a probe (a phenolic compound that inert toward permanganate), the coexisting anilines increased the apparent kinetic constants of 4-HBA oxidation by 1.46–210.82 times. Aromatic anilines could be oxidized by manganese oxides via electron-transfer process, leading to the formation of metastable intermediates known as aniline radicals, which could rapidly oxidize phenolics due to their high reactivities. Additionally, the oxidation products containing aromatic amino or imino groups, formed in the phenolics/anilines binary-contaminants system, can also induce the aforementioned acceleration process, such as benzidine and the cross-coupling products derived from phenolics and anilines. Therefore, even the anilines were consumed up, the accelerating oxidation of 4-HBA by permanganate could be sustained due to the in-situ formed oxidation products. Our study emphasized that the oxidized intermediates and products might influence the reaction pathways involving oxidants and contaminants among the environmental processes, especially in combined pollution system, thereby rendering the transformation pathways of contaminants significantly more intricate than initially anticipated.

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共存的苯胺加速了锰氧化物对酚类物质的氧化

本研究发现，在环境条件下，各种苯胺可以加速高锰酸盐（MnVIIO4−）或铌酸盐（δ-MnO2）对酚类物质的氧化。以苯酚为探针化合物，共存的苯胺使苯酚氧化的表观动力学常数提高了1.73 ~ 18.14倍，这取决于取代基对苯胺和pH条件的影响。此外，以4-羟基苯甲酸（4-HBA）为探针（一种对高锰酸盐惰性的酚类化合物），共存的苯胺使4-HBA氧化的表观动力学常数提高了1.46 ~ 210.82倍。芳香苯胺可以通过电子转移过程被锰氧化物氧化，从而形成亚稳中间体苯胺自由基，苯胺自由基由于其高反应活性而可以迅速氧化酚类物质。此外，在酚类/苯胺类二元污染物体系中形成的含有芳香氨基或亚胺基的氧化产物也可以诱导上述加速过程，如联苯胺和由酚类和苯胺类衍生的交叉偶联产物。因此，即使苯胺被消耗殆尽，由于原位形成的氧化产物，高锰酸盐仍能维持4-HBA的加速氧化。我们的研究强调氧化的中间体和产物可能会影响环境过程中涉及氧化剂和污染物的反应途径，特别是在复合污染系统中，从而使污染物的转化途径比最初预期的要复杂得多。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Water Research 环境科学-工程：环境

CiteScore

20.80

自引率

9.40%

发文量

1307

审稿时长

38 days

期刊介绍： Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include: •Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management; •Urban hydrology including sewer systems, stormwater management, and green infrastructure; •Drinking water treatment and distribution; •Potable and non-potable water reuse; •Sanitation, public health, and risk assessment; •Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions; •Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment; •Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution; •Environmental restoration, linked to surface water, groundwater and groundwater remediation; •Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts; •Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle; •Socio-economic, policy, and regulations studies.