Use of Titanium Dioxide Photocatalysis on the Remediation of Model Textile Wastewaters Containing Azo Dyes

Molecules

Enrico Mendes Saggioro¹  Anabela Sousa Oliveira¹  Thelma Pavesi¹  Cátia Gil Maia¹  Luis Filipe Vieira Ferreira¹ 

[1] ¹Centro de Estudos da Saúde do Trabalhador e Ecologia Humana Escola Nacional de Saúde Pública - Fundação Oswaldo Cruz, Av. Leopoldo Bulhões, 1480, Rio de Janeiro, 21041-210 RJ, Brazil

关键词: photocatalytic degradation;    semiconductor;    photocatalysis;    azo dyes;    TiO₂;    TiO₂ reuse;   

DOI  :  10.3390/molecules161210370

来源: mdpi

【 摘 要 】

The photocatalytic degradation of two commercial textile azo dyes, namely C.I Reactive Black 5 and C.I Reactive Red 239, has been studied. TiO₂ P25 Degussa was used as catalyst and photodegradation was carried out in aqueous solution under artificial irradiation with a 125 W mercury vapor lamp. The effects of the amount of TiO₂ used, UV-light irradiation time, pH of the solution under treatment, initial concentration of the azo dye and addition of different concentrations of hydrogen peroxide were investigated. The effect of the simultaneous photodegradation of the two azo dyes was also investigated and we observed that the degradation rates achieved in mono and bi-component systems were identical. The repeatability of photocatalytic activity of the photocatalyst was also tested. After five cycles of TiO₂ reuse the rate of colour lost was still 77% of the initial rate. The degradation was followed monitoring the change of azo dye concentration by UV-Vis spectroscopy. Results show that the use of an efficient photocatalyst and the adequate selection of optimal operational parameters may easily lead to a complete decolorization of the aqueous solutions of both azo dyes.

【 授权许可】

CC BY   
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.