共查询到20条相似文献,搜索用时 15 毫秒
1.
Degradation of azo dyes in water by Electro-Fenton process 总被引:19,自引:0,他引:19
The degradation of the azo dyes azobenzene, p-methyl red and methyl orange in aqueous solution at room temperature has been studied by an advanced electrochemical oxidation
process (AEOPs) under potential-controlled electrolysis conditions, using a Pt anode and a carbon felt cathode. The electrochemical
production of Fenton's reagent (H2O2, Fe2+) allows a controlled in situ generation of hydroxyl radicals (·OH) by simultaneous reduction of dioxygen and ferrous ions on the carbon felt electrode. In turn, hydroxyl radicals react
with azo dyes, thus leading to their mineralization into CO2 and H2O. The chemical composition of the azo dyes and their degradation products during electrolysis were monitored by high performance
liquid chromatography (HPLC). The following degradation products were identified: hydroquinone, 1,4-benzoquinone, pyrocatechol,
4-nitrocatechol, 1,3,5-trihydroxynitrobenzene and p-nitrophenol. Degradation of the initial azo dyes was assessed by the measurement of the chemical oxygen demand (COD). Kinetic
analysis of these data showed a pseudo-first order degradation reaction for all azo dyes. A pathway of degradation of azo
dyes is proposed. Specifically, the degradation of dyes and intermediates proceeds by oxidation of azo bonds and aromatic
ring by hydroxyl radicals. The results display the efficiency of the Electro-Fenton process to degrade organic matter.
Electronic Publication 相似文献
2.
Covalent organic frameworks(COFs) are nanoporous crystalline polymers with densely conjugated structures. This work discovers that imine-linked COFs exhibit remarkable photodegradation efficiency to azo dyes dissolved in water. Visible light generates different types of radicals from COFs, and superoxide radicals break N═N bonds in dye molecules, resulting in 100% degradation of azo dyes within 1 h. In contrast, these dyes cannot be degraded by conventionally used photocatalysts, for example, Ti... 相似文献
3.
Bin Yan Cuihong Du Meilan Xu Wenchao Liao 《Frontiers of Environmental Science & Engineering》2012,6(6):806-814
The salt-tolerant Staphylococcus cohnii strain, isolated from textile wastewater, has been found effective on decolorizing several kinds of azo dyes with different structures. The optimal conditions for azo dye acid red B (ARB) decolorization by S. cohnii were determined to be pH = 7.0 and 30°C. The decolorization efficiency increased with the increase of the salinity concentration, and around 90% of ARB (100 mg·L?1) could be decolorized in 24 h when the salinity concentration was up to 50 g·L?1. Moreover, the strain could still decolorize 19% of ARB in 24 h even when the NaCl concentration was increased to 150 g·L?1. Meanwhile, the dependence of the specific decolorization rate by S. cohnii on the ARB concentration could be described with Michaelis-Menten kinetics (K m = 585.7mg·L?1, V max = 109.8 mg·g cell?1·h?1). The addition of quinone redox mediator, named 2-hydroxy-1,4-naphthoquinone and anthraquinone-2,6-disulfonate, significantly accelerated the decolorization performance of S. cohnii. Furtherly, the activities of azoreductase (0.55 ??mol·mg protein?1·min?1) and Nicotineamide adenine dinucleotide-dichlorophenol indophenol (NADH-DCIP) reductase (8.9 ??mol·mg protein?1·min?1) have been observed in the crude cell extracts of S. cohnii. The decolorization products of ARB were analyzed by HPLC-MS, and the results indicated the reductive pathway was responsible for azo dye decolorization by S. cohnii. 相似文献
4.
Hu Xiaoyi Lu Jun Liu Yue Chen Liang Zhang Xiwang Wang Huanting 《Environmental Chemistry Letters》2023,21(5):2825-2861
Environmental Chemistry Letters - Valorization of biomass-derived feedstocks for the supply of high-value chemicals, clean fuel and electricity is gaining importance in the context of the circular... 相似文献
5.
Three metallised azo dyes were investigated under TiO2‐photocatalytic and photosensitised conditions in aqueous buffering solutions. The degradation follows apparent first‐order kinetics. The size and strength of intramolecular conjugation determine the light‐fastness of the investigated dyes. Compared with 1O2 produced in photosensitised process, the more powerful *OH radicals in TiCO2 photocatalytic process are highly reactive towards the investigated azo dyes. And as a result, the TiO2‐photocatalysis makes little less distinction in the degradation kinetic data of the azo dyes compared with the photosensitised degradation of them. 相似文献
6.
Tarkwa Jean-Baptiste Oturan Nihal Acayanka Elie Laminsi Samuel Oturan Mehmet A. 《Environmental Chemistry Letters》2019,17(1):473-479
Environmental Chemistry Letters - Textile effluents containing synthetic dyes are one of the most important sources of water pollution. Several dyes are toxic to the aquatic life and... 相似文献
7.
Farooqi Sidra Anis Farooqi Ahmad Salam Sajjad Shamaila Yan Chenglin Victor Ayodele Bamidele 《Environmental Chemistry Letters》2023,21(3):1515-1553
Environmental Chemistry Letters - Global warming is partly caused by massive emissions of carbon dioxide (CO2), a greenhouse gas, in the atmosphere by industrial and other human activities.... 相似文献
8.
Xiaohong GUAN Di HE Jun MA Guanghao CHEN 《Frontiers of Environmental Science & Engineering》2010,4(4):405-413
As a green oxidant, permanganate has received considerable attention for the removal of micropollutants in drinking water treatment. To provide a better understanding of the oxidation of organic micropollutants with permanganate, the oxidation kinetics of 32 micropollutants were compiled. The pollutants include algal toxins, endocrine disrupting chemicals (EDCs), and pharmaceuticals. The oxidation kinetics of micropollutants by permanganate were found to be first order with respect to both contaminant and permanganate concentrations from which second-order rate constants (k″) were obtained. Permanganate oxidized the heterocyclic aromatics with vinyl moiety (i.e., microcystins, carbamazepine, and dichlorvos) by the addition of double bonds. For the polycyclic aromatic hydrocarbons (PAHs) with alkyl groups, permanganate attacked the benzylic C-H through abstraction of hydrogen. The mechanism for the oxidation of phenolic EDCs by permanganate was a single electron transfer and aromatic ring cleavage. The presence of background matrices could enhance the oxidation of some phenolic EDCs by permanganate, including phenol, chlorinated phenols, bisphenol A, and trichlosan. The toxicity of dichlorvos solution increased after permanganate oxidation, and the estrogenic activity of bisphnol A/estrone increased significantly at the beginning of permanganate oxidation. Therefore, the toxicity of degradation products or intermediates should be determined in the permanganate oxidation processes to better evaluate the applicability of permanganate. The influence of background ions on the permanganate oxidation process is far from clear and should be elucidated in the future studies to better predict the performance of permanganate oxidation of micropollutants. Moreover, methods should be employed to catalyze the permanganate oxidation process to achieve better removal of micropollutants. 相似文献
9.
Marbaniang Christopher V. Sathiyan Krishnamoorthy McDonald Thomas J. Lichtfouse Eric Mukherjee Poulami Sharma Virender K. 《Environmental Chemistry Letters》2023,21(3):1729-1743
Environmental Chemistry Letters - The global contamination of water resources by organic contaminants such as pharmaceuticals and pesticides is calling for advanced remediation techniques, yet... 相似文献
10.
Wen Yinghao Yuan Jieming Ma Xingmao Wang Shiren Liu Yuchen 《Environmental Chemistry Letters》2019,17(4):1539-1551
Environmental Chemistry Letters - Water scarcity is a pressing global challenge. Filtration with actual polymeric membranes shows good capability for pollutant separation, but broad applications of... 相似文献
11.
Zhang Shengqi Zhang Kaiting Xie Yuwei Lou Yao-Yin Lichtfouse Eric Feng Mingbao Sharma Virender K. 《Environmental Chemistry Letters》2023,21(6):3377-3391
Environmental Chemistry Letters - The worldwide demand for clean water is rising worldwide, yet wastewater decontamination is actually limited by the presence of refractory organic and inorganic... 相似文献
12.
Sarojini G. Kannan P. Rajamohan Natarajan Rajasimman Manivasagan Vo Dai-Viet N. 《Environmental Chemistry Letters》2023,21(2):1029-1058
Environmental Chemistry Letters - Most dyes are pollutants that should be removed from waters due to their mutagenic and carcinogenic properties, requiring advanced adsorption methods. Here, we... 相似文献
13.
Ali Ahsan Chen Longbin Nasir Muhammad Salman Wu Chao Guo Baolin Yang Yaodong 《Environmental Chemistry Letters》2023,21(2):1075-1092
Environmental Chemistry Letters - In the context of climate change, freshwater shrinkage and industrialization, human diseases are increasing due to water pollution by toxic chemicals and... 相似文献
14.
Morin-Crini Nadia Lichtfouse Eric Liu Guorui Balaram Vysetti Ribeiro Ana Rita Lado Lu Zhijiang Stock Friederike Carmona Eric Teixeira Margarida Ribau Picos-Corrales Lorenzo A. Moreno-Piraján Juan Carlos Giraldo Liliana Li Cui Pandey Abhishek Hocquet Didier Torri Giangiacomo Crini Grégorio 《Environmental Chemistry Letters》2022,20(4):2311-2338
Environmental Chemistry Letters - Water contamination by emerging contaminants is increasing in the context of rising urbanization, industrialization, and agriculture production. Emerging... 相似文献
15.
Fuqiang Liu Shengtao Jiang Shijie You Yanbiao Liu 《Frontiers of Environmental Science & Engineering》2023,17(2):18
16.
水生维管束植物在水污染中的应用 总被引:5,自引:3,他引:5
随着水污染的加剧,高效低耗的水污染处理技术逐渐受到人们的重视,水生维管束植物以其特有的组织和生态功能及易于人工操纵等原因而在净化水体污染、防治富营养化方面发挥了重要的作用。文章对水生维管束植物在水质净化中的作用、影响因素、水生植物的综合利用及其在水污染监测中的作用等方面进行了系统分析,提出多种植物组合比单种植物能更好地实现对水体的净化,通过温度、水深的调控措施可以加强水生维管束植物对水质的净化效果,温度、水深、水质状况以及水生植物的经济价值等是水生植物选择的重要因素。指出了当前水生维管束植物研究中存在的一些问题,认为在人为操纵下,对于水生植物的长效管理是其在水污染应用中的一个重要内容。 相似文献
17.
Environmental Chemistry Letters - Nitric oxide, ammonia and volatile organic compounds are common air pollutants which need to be removed for health security. To reach ultra-low emission standards,... 相似文献
18.
The purpose of the research was to estimate optimal conditions for wet oxidation (WO) of debarking water from the paper industry.
The WO experiments were performed at various temperatures, partial oxygen pressures and pHs. The experiments showed that lignin
degradation and organics removal are affected remarkably by temperature and pH. At different WO conditions (pH 12, T 130–200°C), 78–97% of lignin reduction was detected. pH value of 12 caused faster removal of tannins/lignin content; pH value
of five was more effective for removal of total organics, represented by chemical oxygen demand (COD) and total organic carbon.
The highest biodegradability [biological oxygen demand (BOD)/COD] of 0.72 was obtained at a pH of ten and temperature of 200°C. 相似文献
19.
Silvestri Siara Fajardo Andr R. Iglesias Bernardo A. 《Environmental Chemistry Letters》2022,20(1):731-771
Environmental Chemistry Letters - Porphyrins are differentiated π-conjugated compounds with unique photochemical and redox properties. The tetrapyrrole macrocycle core of porphyrins is... 相似文献
20.
Khandelwal Kapil Nanda Sonil Boahene Philip Dalai Ajay K. 《Environmental Chemistry Letters》2023,21(5):2619-2638
Environmental Chemistry Letters - The rising issues of global warming due to the rapid use of fossil fuels are calling for sustainable energies such as dihydrogen, thereafter named... 相似文献