Combinative Sonolysis and Photocatalysis for Textile Dye Degradation

Abstract

The merits of combining two advanced oxidation processes, viz., sonolysis and photocatalysis, have been evaluated by investigating the degradation of an azo dye, naphthol blue black (NBB), using a high-frequency ultrasonic generator and UV−photolysis. An additive effect on the degradation rate of the parent compound is observed when the sonolysis and photocatalysis experi ments were carried out in a simultaneous or sequential manner. Sonolysis is effective for inducing faster degradation of the parent dye, while TiO2 photocatalysis is effective for promoting mineralization.

The combination of heterogeneous photocatalysis with chemical and physical operations: A tool for improving the photoprocess performance

“…Hydrogen radicals from the above reaction can also interact with the oxygen present in the system to form peroxide radicals, HO 2 • , and hydrogen peroxide, H 2 O 2 . Different research groups under rather different experimental conditions [10][11][12][13][14][15][16][17][18][19][20] have recently examined the combination of ultrasound and photocatalysis (sonophotocatalysis). The simultaneous use of both techniques for degradation of organic pollutants in water was reported to be more effective than their sequential combination [13] and in several cases to lead to more than additive effects [14].…”

“…Different research groups under rather different experimental conditions [10][11][12][13][14][15][16][17][18][19][20] have recently examined the combination of ultrasound and photocatalysis (sonophotocatalysis). The simultaneous use of both techniques for degradation of organic pollutants in water was reported to be more effective than their sequential combination [13] and in several cases to lead to more than additive effects [14]. When photocatalysis was combined with high frequency sonolysis, the overall degradation rate was found to be equal to the sum of the individual rates for photocatalysis and sonolysis [13,15] and beneficial effects were noticed on the mineralization rate [16].…”

“…The simultaneous use of both techniques for degradation of organic pollutants in water was reported to be more effective than their sequential combination [13] and in several cases to lead to more than additive effects [14]. When photocatalysis was combined with high frequency sonolysis, the overall degradation rate was found to be equal to the sum of the individual rates for photocatalysis and sonolysis [13,15] and beneficial effects were noticed on the mineralization rate [16]. When photocatalysis was combined with low frequency ultrasound, strong synergistic effects [15,[17][18][19] or no effect [20], also depending on the specific ultrasound power [12], have been reported.…”

Degradation of Rhodamine B Dye by TiO2Nanotubes Photocatalyst Synthesized via Alkaline Hydrothermal Method

“…Currently, the conventional method used to degrade the dye of the contaminated water include primary (adsorption, flocculation), secondary (biological methods), and chemical processes (chlorination, ozonization) [8][9]. However, the drawback of these methods is that they only transfer the non-biodegradable matter into sludge, giving rise to a new type of pollution, which needs further treatment [10][11]. Among various oxide semiconductor photocatalysts, TiO 2 photocatalyst is found to be a more efficient catalyst for photocatalytic degradation of pollutants due to faster electron transfer to molecular oxygen [12].…”

Photocatalytic Degradation of Vat Red 13 by Green Synthesized Copper Oxide Nanocatalyst

“…hand, these procedures are non-destructive because they simply transport the non-biodegradable substance into slush and provide a new-fangled type of contamination, which requests additional treatment [11][12][13].…”