Photocatalytic Decolorization of Commercial Acid Dyes using Solar Irradiation

Abstract

This work investigates the solar heterogeneous photocatalytic degradation of three commercial acid dyes: Blue 9 (C.I. 42090), Red 51 (C.I. 45430), and Yellow 23 (C.I. 19140). TiO 2 P25 from Degussa was used as the photocatalyst. The dyes were completely degraded within 120 min of treatment in the following increasing order of removal rate: Blue 9 < Yellow 23 < Red 51. The photocatalytic color removal process was well described by a two-firstorder in-series reaction, followed by another firstorder reaction. Photolytic experiments showed that this process is quite inefficient and highly selective towards Red 51 only. The dyes' solution was completely decolorized and organic matter removals up to 99% were achieved with photocatalysis. The lack of selectivity and the possibility of using solar light to excite the photocatalyst are promising results regarding the feasibility of this technology.

A quick assessment of the photocatalytic activity of TiO2 pigments — From lab to conservation studio!

“…Similar experimental setups have been reported in literature [19,[38][39][40]. Each test is optimized for a specific purpose but all these tests have a similar approach.…”

Kinetic analysis of C.I. Acid Yellow 9 photooxidative decolorization by UV–visible and chemometrics

“…Acid Yellow 9 using Mn oxide [2], biodegradation [3] and electrochemical oxidation [4,7] have been reported. Nowadays, however, homogeneous and heterogeneous dye removal techniques that allow fast degradations are the methods most commonly used for the degradation of organic dyes [1,[8][9][10][11][12][13][14]. Regardless of which technique is used, the challenge of determining the optimal conditions for rapid dye removal is usually solved by determining the kinetic rate and using it as a reference parameter.…”