Photocatalytic activation of TiO2 under visible light using Acid Red 44

Moon, Jei‐Kwon; Yun, Chul Yong; Chung, Kyung-Won; Kang, Myung‐Hee; Yi, Jongheop

doi:10.1016/j.cattod.2003.10.009

Cited by 137 publications

(63 citation statements)

References 14 publications

(15 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Assim, as espécies com cargas negativas em meio ácido não sofrem repulsão eletrostática. Na faixa de pH entre 1 e 6, a espécie 18,[26][27][28] . De acordo com Monn et al 26 , as Equações que se seguem representam o estado do TiO 2 em meio aquoso.…”

Section: Figura 4 Refletores Semi-circulares Montados Acima Do Fotorunclassified

Aplicação de radiação UV artificial e solar no tratamento fotocatalítico de efluentes de curtume

Pascoal¹,

Lima²,

Sousa³

et al. 2007

Quím. Nova

View full text Add to dashboard Cite

Recebido em 18/1/06; aceito em 15/1/07; publicado na web em 17/7/07 APPLICATION OF ARTIFICIAL AND SOLAR UV RADIATION IN THE PHOTOCATALYTIC TREATMENT OF A TANNERY EFFLUENT. Tannery effluents are very dangerous for the environment since they contain large amounts of dangerous and biorecalcitrant contaminants (organic matter and Cr(VI)). This paper reports the efficiency of heterogeneous photocatalysis, based on the application of solar and artificial radiation, furnished by UV lamps, using TiO 2 fixed on a flat plate, in the treatment of synthetic effluents. The results of COD and Cr(VI) demonstrate that the use of solar radiation is the most efficient way to perform the photocatalytic treatment of these effluents since a minimum removal of 62 and 61% was observed for Cr(VI) and organic matter, respectively. Keywords: heterogeneous photocatalysis; artificial radiation; solar radiation. INTRODUÇÃOA maior parte dos impactos ambientais gerados pela sociedade contemporânea de países desenvolvidos ou em desenvolvimento tem sua gênese no setor industrial. Este setor é um grande consumidor de recursos naturais e um grande produtor de dejetos que, geralmente, são descartados no meio ambiente -no estado in natura ou ineficientemente tratados -em especial, nos ecossistemas aquáti-cos 1 . As indústrias de curtimento de couro são valorosas representantes do extraordinário potencial poluidor do segmento industrial. Todo o processo produtivo do couro curtido consome grande quantidade de água e, por conseguinte, gera também expressiva quantidade de efluentes líquidos e resíduos sólidos. Em média, a produção de 250 kg de couro curtido é feita a partir de 1 t de pele salgada, sendo necessária a aplicação de 30.000 L de água para todo o processo de curtimento 2 . Assim, em média, as indústrias de curtume finalizam cerca de 20 a 30% de sua matéria-prima, resultando na produção média de 600 kg de resíduos sólidos e 50 m 3 de efluentes líquidos (com 250 kg de DQO e 100 kg de DBO) 3 . As águas residuárias de curtumes já são submetidas a processos de tratamento preliminar (gradeamento, mistura e homogeneização, retenção de gordura e lançamento em vazão regularizada), primário (coagulação, floculação e decantação) e secundário (aplicação de lodos ativados, valos de oxidação, lagoas aeradas, facultativas etc) 4 . No entanto, em indústrias de grande porte essas etapas de tratamento não se mostram eficazes para que os efluentes tratados tenham as características desejáveis para serem descartados no meio ambiente, especialmente em relação aos teores de material orgânico e cromo. As afirmações anteriores podem ser contextualizadas com dois exemplos reais de produção de efluentes de curtume perigosos para o meio ambiente. Segundo Gomes et al. . Segundo esses autores, na Índia a produção de couro concentra-se nos estados de Unnao, Kanpur e Uttar Pradesh, havendo em Unnao uma central de tratamento dos efluentes dos curtumes (CETP) pertencentes aos estados de Unnao e Uttar Pradesh. Os curtumes desses estados produzem efluentes com 62 ± 34 mg L -...

show abstract

Section: Figura 4 Refletores Semi-circulares Montados Acima Do Fotorunclassified

Aplicação de radiação UV artificial e solar no tratamento fotocatalítico de efluentes de curtume

Pascoal¹,

Lima²,

Sousa³

et al. 2007

Quím. Nova

View full text Add to dashboard Cite

show abstract

“…Dissolved oxygen molecules (in the aqueous system), or other electron acceptors available in the aqueous system can cause this reduction [11,12]. After successive free radical attack and fragmentation, most organics are mineralized to water, carbon dioxide and mineral acids [2,13]. González investigated the sonophotocatalytic degradation of methylene blue and found that degradation reaction followed apparent first-order kinetics and was dependent on the pH solution with the highest degradation at pH 7 [14].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of Influencing Factors and Kinetics in Catalytic Removal of Methylene Blue with TiO2 Nanopowder

Salehi¹,

Hashemipour²,

Mirzaee³

2012

AJEE

111

View full text Add to dashboard Cite

In this research, degradation of methylene blue as a dye pollutant was investigated in the presence of TiO 2 nanopowders using photolysis and sonolysis systems separately and simultaneously. Effect of different parameters such as catalyst dosage, initial concentration of dye, UV power, pH and type of catalyst on the removal efficiency was ascertained. The results showed that basic pH is proper for the photocatalytic removal of the dye. Furthermore higher UV power and lower initial concentration of dye leads to higher removal percent. Moreover TiO 2 showed more photocatalytic activity than ZnO in the nanopowder form. The experimental kinetic data followed the pseudo-first order model in both photocatlytic and sonophotocatalytic processes but the rate constant of sonophotocatalysis is higher than it at photocatalysis process. Finally the reaction order of the rate law respect to nanocatalyst dosage in photocatalysis process is obtained 1.45. High activation energy of this process shows its high sensitivity to temperature.

show abstract

“…Additionally, degradation, detoxification, and/or bactericidal effects of TiO 2 NPs under UVA to some pesticides or drugs in the ecosystem have been widely investigated. 76 (λ .350 nm), a TiO 2 electron excites an electron from the valance band to the conduction band and electron hole pairs are generated in the surface of TiO 2 , which consists of the positive hole (h + ) and electron (e -). The hole in the valence band has a positive redox potential and is capable of oxidizing organics, H 2 O, and hydroxide ions on the surface of TiO 2 NPs, and eventually to generate hydroxyl radicals (OH).…”

Section: Effects Of Tio 2 Np Interaction With Organic and Inorganic Cmentioning

confidence: 99%

Toxic effects of the interaction of titanium dioxide nanoparticles with chemicals or physical factors

Liu

Lin²,

Zhao

2013

IJN

View full text Add to dashboard Cite

Due to their chemical stability and nonallergic, nonirritant, and ultraviolet protective properties, titanium dioxide (TiO 2 ) nanoparticles (NPs) have been widely used in industries such as electronics, optics, and material sciences, as well as architecture, medicine, and pharmacology. However, increasing concerns have been raised in regards to its ecotoxicity and toxicity on the aquatic environment as well as to humans. Although insights have been gained into the effects of TiO 2 NPs on susceptible biological systems, there is still much ground to be covered, particularly in respect of our knowledge of the effects of the interaction of TiO 2 NPs with other chemicals or physical factors. Studies suggest that interactions of TiO 2 NPs with other chemicals or physical factors may result in an increase in toxicity or adverse effects. This review highlights recent progress in the study of the interactive effects of TiO 2 NPs with other chemicals or physical factors.

show abstract

Photocatalytic activation of TiO2 under visible light using Acid Red 44

Cited by 137 publications

References 14 publications

Aplicação de radiação UV artificial e solar no tratamento fotocatalítico de efluentes de curtume

Aplicação de radiação UV artificial e solar no tratamento fotocatalítico de efluentes de curtume

Experimental Study of Influencing Factors and Kinetics in Catalytic Removal of Methylene Blue with TiO2 Nanopowder

Toxic effects of the interaction of titanium dioxide nanoparticles with chemicals or physical factors

Contact Info

Product

Resources

About