Advanced oxidation processes for the treatment of wastes polluted with azoic dyes

Faouzi, Mouna; Cañizares, Pablo; Gadri, Abdellatif; Lobato, Justo; Bensalah, Nasr; Paz, R.; Rodrigo, Manuel A.; Sáez, Cristina

doi:10.1016/j.electacta.2006.05.011

Cited by 147 publications

(118 citation statements)

References 42 publications

Supporting

Mentioning

109

Contrasting

Unclassified

Order By: Relevance

“…3 In this context, in the recent years many works have been focused on the study of the electrochemical treatment with conductive diamond anodes of synthetic [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] and actual [23][24][25][26] wastewaters polluted with organics, and the results obtained have been compared to those attained with other commonly used AOP. 23,24,26,27 Likewise, it has also been characterized some aspects about the oxidation mechanisms involved in the conductive diamond electrooxidation, including direct electrooxidation, hydroxyl radical mediated oxidation, and oxidation mediated by oxidants generated during the treatment (from the salts contained in the waste 28 ). The combination of these oxidation mechanism can be responsible for the better results (efficiencies and mineralization ratios) obtained by this technology.…”

Section: Introductionmentioning

confidence: 99%

Electrosynthesis of ferrates with diamond anodes

2008

View full text Add to dashboard Cite

This work is focused on the electrosynthesis of ferrates with boron-doped diamond (BDD) anodes. These compounds are oxo-anions of Fe(V) and Fe(VI) with a very high oxidant potential over a wide range of pHs, and with a great variety of industrial and environmental applications. It has been observed that the use of BDD electrodes can improve the results obtained by steel electrodes in the synthesis of ferrates. However, the results seem to be limited by the availability of oxidizable iron species in the reagent solution. The production yield is revealed to be strongly dependent on the iron raw material, hydroxyl anions concentration, temperature, and current density. The use of iron-powder bed as iron-raw material increases the availability of oxidizableiron species and therefore allows improving the efficiency of the electrosynthesis with BDD. Likewise, current densities over 1000 A m 22 and temperatures around 258C guaranty high current efficiencies and ferrates concentrations.

show abstract

Section: Introductionmentioning

confidence: 99%

Electrosynthesis of ferrates with diamond anodes

2008

View full text Add to dashboard Cite

show abstract

“…Excessive use of chemicals in dye treatment creates secondary pollution problems to the environment. (Ahmed et al, 2005;Ibrahim et al, 2009) (Bisschops and Spanjers, 2003;Dos Santos et al, 2006) Treatment using ozonation, Fenton's reagent, electrochemical destruction and photocatalysis are some of the emerging techniques reported to have potential use for decolorization (Faouzi et al, 2006;Ay et al, 2009). However, such technologies usually involve complicated procedures and are economically unattainable (Chang and Lin, 2000).…”

Section: Treatment Technologymentioning

confidence: 99%

Sequential Anaerobic-Aerobic Phase Strategy Using Microbial Granular Sludge for Textile Wastewater Treatment

Muda¹,

Aris²,

Salim³

et al. 2013

Biomass Now - Sustainable Growth and Use

View full text Add to dashboard Cite

“…44 Aliado a isso, a complexidade e a estabilidade química dos corantes estudados também contribuem para os valores de remoção de COT baixos e a energia elétrica consumida para sua mineralização. Faouzi et al, 45 usando anodo de Si/ DDB, mostraram que a eletrooxidação de dois corantes distintos pode implicar a remoção concomitante da demanda química de oxigênio (DQO) e COT, dependendo do peso molecular e da estrutura quími-ca dos corantes. Quanto maior o peso molecular e correspondente estrutura química mais complexa com a presença de vários grupos funcionais, maior a geração de intermediários reacionais (quebra de grupos cromóforos) do que a formação de CO 2 .…”

Section: Figura 3 Decaimento Relativo (A) Absorbância (B) áRea Cromaunclassified

Electrochemical Oxidation of Reactive Black 5 and Blue 19 Dyes Using a Non Commercial Boron-Doped Diamond Electrode

Vasconcelos¹,

Souza²,

Guaraldo³

et al. 2016

Química Nova

View full text Add to dashboard Cite

respectively azo and anthraquinone textile dyes, by electrochemical oxidation using a non commercial boron doped diamond electrode supported on titanium metallic with a relation between B and C equal to 15,000 ppm. Pt was used as counter electrode and Ag/AgCl (sat) was the reference electrode. The variables investigated to optimize the degradation were support electrolyte concentration (0.05, 0.1 and 0.2 mol L -1 of K 2 SO 4 ), temperature (25, 35 and 45 ºC) and pH (2.5 and 10) by applying a current density of 75 mA cm -2. Total decolorization was observed in all electrochemical conditions studied. The highest rates of mineralization and chromatographic area removal were attained at high support electrolyte concentration due to the increase of conductivity, which caused more generation of hydroxyl radicals. RP5 was degraded at lower electrolysis time than RA19 with smaller requirement of electric charge. The mineralization rate increased in acid medium and at higher temperature since the increase in temperature favors the generation reactions of persulfate. These conditions led to the highest levels of current efficiencies and lower energy consumed.Keywords: boron-doped diamond electrode; Reactive Black 5; Reactive Blue 19; decolorization; hydroxyl radical; persulfate. INTRODUÇÃOOs corantes sintéticos são compostos de extrema importância para o setor industrial, principalmente, para as indústrias têxteis que são responsáveis pela enorme descarga de efluentes contendo corantes e outros resíduos indesejáveis, sendo potenciais poluidoras ambientais. 1-4Os efluentes têxteis apresentam alta demanda química e biológica de oxigênio, elevada salinidade e intensa coloração devido à presença de corantes, os quais são fotolítica e quimicamente estáveis, podem exibir toxicidade aguda e serem carcinogênicos e/ou mutagênicos. Sendo assim, quando os corantes são descartados incorretamente no meio ambiente podem ocasionar problemas ambientais e, sobretudo, ser nocivos à saúde humana e dos animais. 5,6 Os corantes reativos, por exemplo, são solúveis em água, aniôni-cos e ligam-se às fibras do tecido por meio de ligações covalentes, pela reação de adição nucleofílica do grupo vinilsulfona ao grupo hidroxila da celulose, o que confere ao tecido tingido alta estabilidade da cor adquirida. 7,8 Entretanto, esses corantes apresentam baixa eficiência de fixação às fibras devido à competitividade de duas reações, a primeira sendo do grupo reativo vinilsulfona com as fibras e a segunda a reação de hidrólise do grupo vinilsulfona produzindo o 2-hidroxietilsulfona, que não se fixa a fibra e é perdido no efluente.9 As Figuras 1a e 1b ilustram as estruturas moleculares de dois corantes reativos, o Reativo Preto 5 (RP5) e o Azul (RA19), respectivamente, que apresentam como grupo reativo a sulfatoetilsulfonila.O corante RP5, com grupo cromóforo azo, é um dos corantes mais utilizados no tingimento de algodão, no qual emprega-se, aproximadamente, 40 g do corante dissolvidos em 70 a 150 L de água para cada kg de algodão tingido. 10 No entanto, ...

show abstract

Advanced oxidation processes for the treatment of wastes polluted with azoic dyes

Cited by 147 publications

References 42 publications

Electrosynthesis of ferrates with diamond anodes

Electrosynthesis of ferrates with diamond anodes

Sequential Anaerobic-Aerobic Phase Strategy Using Microbial Granular Sludge for Textile Wastewater Treatment

Electrochemical Oxidation of Reactive Black 5 and Blue 19 Dyes Using a Non Commercial Boron-Doped Diamond Electrode

Contact Info

Product

Resources

About