Mineralization of aniline and 4-chlorophenol in acidic solution by ozonation catalyzed with Fe2+ and UVA light

Sauleda, Roser; Brillas, Enric

doi:10.1016/s0926-3373(00)00197-1

Cited by 186 publications

(80 citation statements)

References 24 publications

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“…One is that Cl À reacts with OH to produce ClOH À , and the latter evolves to Cl (see Reactions 3,4). Parameters in Reactions 5 and 6 show FeOH 2þ is the more photoactive species to form OH than Fe 3þ .…”

Section: Resultsmentioning

confidence: 99%

“…[2] Most research has focussed on the complete mineralisation of aniline, in which the total organic carbon (TOC)-chemical oxygen demand (COD) deletion percentage was often the important assessment index discussed. [3][4][5] Piccinini et al [6] found that the aniline remained unaltered when irradiated without catalyst (TiO 2 ), and the oxidative pathway of forming aminophenols dominated in the presence of TiO 2 . Previous studies primarily discussed the oxidation processes, [7] whereas information on the processes of aniline halogenation under photochemical situations, the chlorination process for instance, seems to be scarce.…”

Section: Introductionmentioning

confidence: 99%

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Photochlorination of aniline in Fe3+-containing saline water under simulated solar light irradiation

2012

Environ. Chem.

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Environmental context. Aromatic amines are widely used chemicals, which show enhanced toxicity and longer environmental persistence when halogenated. We investigated the chlorination of aniline in seawater and in natural aqueous solutions containing Fe 3þ and Cl À , under simulated sunlight irradiation. The results increase our understanding of the transformation pathway of typical nitrogen-containing aromatic contaminants in the environment.Abstract. Photochlorination of aniline was observed in aqueous solutions containing dissolved Fe III and chloride ions under simulated solar light irradiation. Effects of O 2 , Cl À , Fe 3þ and pH on the formation of chloroanilines (CAs) were investigated. para-chloroaniline (4CA) was identified as the main chlorinated product. The formation of 4CA is enhanced with increased concentrations of Cl À or Fe 3þ , and decreased pH, whereas oxygen plays a negligible role in the process. The results indicate that, Cl is formed mainly by the photodissociation of FeCl 2þ -FeCl 2 þ complexes, and reacts with Cl À to produce Cl 2 À . Aniline is then oxidised by Cl 2 À into an anilino radical cation, which further reacts with Cl 2 À to generate CAs. The photochlorination of aniline in natural seawater was also observed. Other phototransformation products of aniline were detected and a transformation pathway was proposed. This work provides evidence for the photochemical chlorination path of aniline-based aromatic amines in aqueous solutions.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Photochlorination of aniline in Fe3+-containing saline water under simulated solar light irradiation

2012

Environ. Chem.

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“…La concentration en peroxyde d'hydrogène doit en outre être optimisée. L'efficacité de ces procédés dépend de la concentration en réactifs (O 3 et H 2 O 2 ) et des longueurs d'onde appliquées (SAULEDA et BRILLAS, 2001). Comme on a pu le voir, l'utilisation de radiations UV permet d'augmenter sensiblement le taux de dégradation des composés organiques.…”

Section: Application Des Procédés Photocatalytiques En Phase Homogèneunclassified

Procédés d’oxydation avancée dans le traitement des eaux et des effluents industriels: Application à la dégradation des polluants réfractaires

Zaviska

Drogui

Mercier

et al. 2009

rseau

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Cette synthèse traite des procédés d’oxydation avancée (POA) pour le traitement des eaux et des effluents industriels. Ces procédés mettent pour la plupart en combinaison deux ou trois réactifs (oxydants) afin de produire des radicaux hydroxyles. Les radicaux libres sont des espèces hautement actives capables de réagir rapidement et de manière non sélective sur la plupart des composés organiques, réputés difficilement oxydables par voie biologique ou par des traitements chimiques conventionnels. Les POA peuvent être subdivisés en quatre groupes : les procédés d’oxydation chimique en phase homogène (H2O2/Fe2+ et H2O2/O3), les procédés photocatalytiques en phase homogène et/ou hétérogène (H2O2/UV, O3/UV et Fe2+/H2O2/UV; TiO2/UV), les procédés d’oxydation sonochimique et les procédés d’oxydation électrochimique. Le couplage H2O2/Fe2+ représente le système d’oxydation avancée le plus connu et le moins complexe, lequel est souvent employé dans le traitement des effluents industriels. Cependant, dans le domaine de la potabilisation des eaux, le système le plus utilisé et le plus éprouvé est le couplage H2O2/O3 couramment employé pour l’élimination des composés phytosanitaires (pesticides). Les procédés d’oxydation électrochimiques, photocatalytiques et sonochimiques sont des technologies qui nécessitent en général moins de réactif et sont faciles d’automatisation par comparaison aux autres POA. Ces procédés sont présentement en pleine expansion dans le domaine des technologies environnementales, ceci afin d’améliorer les systèmes existants de traitement des eaux usées municipales et industrielles, ou à remplacer les technologies conventionnelles peu efficaces pour l’enlèvement de contaminants organiques réfractaires, inorganiques et microbiens. De nombreuses études réalisées à l’échelle laboratoire ont clairement prouvé l’efficacité des POA pour le traitement de divers effluents. Cependant, le développement de ces procédés dans les filières de traitement des eaux reste encore limité en raison des coûts d’investissement et des coûts opératoires associés. Des solutions et stratégies sont proposées dans ce document, telles que le développement de procédés hybrides et leur couplage avec des traitements biologiques conventionnels, et ce, afin de pallier certaines contraintes spécifiques des POA et faciliter ainsi leur insertion dans les filières de traitement des eaux et des effluents industriels. Ce document a pour objectif de faire une synthèse des différents POA, d’en expliquer leur principe de fonctionnement, de déterminer les différents paramètres les gouvernant, ainsi que leurs applications dans le traitement des eaux et des effluents.This review deals with advanced oxidation processes (AOP) for water and wastewater treatment. Most AOPs combine two or three chemical oxidants in order to produce hydroxyl radicals. These free radicals are species capable of oxidizing numerous complex organic, non-chemically oxidizable or difficulty oxidizable compounds. They efficiently react with carbon-carbon double bonds and attack t...

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“…Dentre estas variáveis, o estudo de diferentes metais de transição tem recebido grande destaque 22,33,36,39 . Vários metais foram estudados por diferentes grupos de pesquisa, sendo que, mais uma vez, a eficiência destas espécies depende de vários fatores experimentais 36,39 . Entretanto, o consumo de ozônio, a toxicidade do metal, possibilidade de reaproveitamento e o custo também devem ser considerados na avaliação do processo.…”

Section: Ozônio Catalítico Homogêneounclassified

“…No processo de fotocatálise/TiO 2 / ozônio tem-se, dentre outras, as seguintes reações envolvidas: A presença de ozônio pode diminuir a recombinação dos elé-trons com as lacunas, levando à maior geração de radicais hidroxilas e, conseqüentemente, à melhor eficiência do processo fotocatalítico. O O 3 é melhor aceptor de elétrons que o O 2 (que é a substância mais utilizada para esta função) e, devido a isto, há melhoras na eficiência e cinética do processo 39,40 .…”

Section: Reações Na Superfície Em Meio áCidounclassified

Métodos emergentes para aumentar a eficiência do ozônio no tratamento de águas contaminadas

Mahmoud¹,

Freire²

2007

Quím. Nova

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Recebido em 30/9/05; aceito em 6/2/06; publicado na web em 30/8/06 NEW METHODS FOR ENHANCING OZONE EFFICIENCY ON CONTAMINATED WATER TREATMENT. Many industrial processes produce effluents with a wide variety of xenobiotic organic pollutants, which cannot be efficiently degraded by conventional biological treatments. Thus, the development of new technologies to eliminate these refractory compounds in water has become very imperative in order to assure the quality of this important resource. Ozonation is a very promising process for the treatment of wastewaters containing non-easily removable organic compounds. The present work aims at highlighting new methods of enhancing the efficiency of ozone towards the removal organic pollutants in aqueous solution. Special attention is given to catalytic ozonation processes contemplating homo-and heterogeneous catalysis, their activity and mechanisms. Recent results and future prospects about the application of these processes to real effluents are also evaluated.Keywords: catalytic ozonation; environmental chemistry; advanced oxidation processes. INTRODUÇÃODesde as últimas décadas do século passado, a sociedade tem adquirido uma conscientização crescente a respeito dos problemas ambientais e seus efeitos para a qualidade de vida desta e das futuras gerações. Apesar disso, a integridade de vários ecossistemas vem sendo afetada, de maneira preocupante, por uma série de atividades antropogênicas, levando a um risco de degradação irreversível do meio ambiente.Neste panorama, as preocupações com o uso e a qualidade da água adquirem especial importância devido à relevância deste recurso e ao aumento desenfreado de sua demanda, resultante principalmente do crescimento acelerado da população e estilo de vida da sociedade contemporânea (que dentre outras coisas, prima por padrões de conforto e bem-estar em detrimento do equilíbrio dos recursos naturais). De fato, é difícil imaginar qualquer tipo de organização dos seres humanos em sociedade que dispense o uso da água, uma vez que esta substância é essencial não somente para a manutenção das atividades biológicas básicas (a água compõe parte significativa das células de todos os seres vivos, estando envolvida em processos de transporte de nutrientes e dejetos; manutenção de temperatura; produção e armazenamento de energia, etc.), mas também para o desenvolvimento das atividades produtivas (agrícolas ou industriais).Talvez por ser relativamente abundante, a água tornou-se tão banal que sua presença, embora indispensável, não desperta a merecida atenção e valorização. Apesar da água ser um recurso natural renovável (qualquer que seja seu uso, no final ela é restituída ao ambiente/origem), durante muito tempo teve-se uma concepção errônea de inesgotabilidade desta substância. Embora seja verdade que o homem não faça a água simplesmente desaparecer da natureza (como tem feito com florestas e algumas reservas minerais), a qualidade de uma infinidade de recursos hídricos tem sido seriamente comprometida 1,2 .Dentre as várias atividades ant...

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Mineralization of aniline and 4-chlorophenol in acidic solution by ozonation catalyzed with Fe2+ and UVA light

Cited by 186 publications

References 24 publications

Photochlorination of aniline in Fe3+-containing saline water under simulated solar light irradiation

Photochlorination of aniline in Fe3+-containing saline water under simulated solar light irradiation

Procédés d’oxydation avancée dans le traitement des eaux et des effluents industriels: Application à la dégradation des polluants réfractaires

Métodos emergentes para aumentar a eficiência do ozônio no tratamento de águas contaminadas

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