Photocatalytic degradation of Rhodamine B dye with TiO2 immobilized on SiC foam using full factorial design

Abstract

Textile effluents treatment is one of the important environmental challenges nowadays. Photocatalysis has proven its effectiveness for the removal of recalcitrant compounds, and it is considered as a green technology for the treatment of effluents. However, good photocatalytic yield is strongly related to the operating parameters. In this study, a supported TiO2 on a β-SiC foam was tested for the removal of Rhodamine B (RhB). The photocatalytic discoloration of RhB synthetic solution in our condition was about 90%. The effects of each parameter were assessed through a full factorial design. Sixteen tests were carried out and the response was RhB removal. The most influent parameters were TiO2/β-SiC foam quantity, the concentration of RhB, the volume of H2O2 and pH. Their contributions on RhB removal were, respectively, 53.01, 30.49, 2.7, and 2.48% according to Pareto diagram. Analysis of the coefficients shows that initial concentration of RhB and volume of H2O2 had a negative effect on the response. However, the quantity of TiO2/β-SiC foam and pH had a positive effect on the response. The influence of the flow rate on the process was assessed. The results showed a slight increase in RhB removal. Furthermore, the aging test of TiO2/β-SiC foam on the photocatalytic efficiency was carried out after ten successive photocatalysis tests. Only 6.7% loss of yield was observed. These results are very encouraging for an application at the industrial scale.

Synthesis of Thin Titania Coatings onto the Inner Surface of Quartz Tubes and Their Photoactivity in Decomposition of Methylene Blue and Rhodamine B

“…The value reported for MB is in a very good agreement with that (0.014 min −1 ) reported over a P25 titania catalyst [57]. The rate constant for the decomposition of RhB exceeds this value (0.0194 min −1 ) reported over a TiO2/SiC catalyst [16]. The coatings obtained were tested in the decomposition of two organic compounds at 20 • C. The kinetic data were corrected by subtracting the rate of non-catalytic reaction measured in a blank experiment with a non-coated tube.…”

“…The value reported for MB is in a very good agreement with that (0.014 min −1 ) reported over a P25 titania catalyst [57]. The rate constant for the decomposition of RhB exceeds this value (0.0194 min −1 ) reported over a TiO2/SiC catalyst [16].…”

“…The value reported for MB is in a very good agreement with that (0.014 min −1 ) reported over a P25 titania catalyst [57]. The rate constant for the decomposition of RhB exceeds this value (0.0194 min −1 ) reported over a TiO 2 /SiC catalyst [16]. The heat transfer coefficient increases at high gas flow rate and therefore the slope of the minimum temperature line (shown in red in Figure 7) decreases.…”

“…Thin titania coatings [10,11], titania nanoparticles (NPs) [12][13][14][15], and supported titania catalysts [16] were widely employed in the decomposition of organic dyes. Among them, the suspension of colloidal NPs demonstrated the highest productivity, because it provides a good contact between the titania and the organic pollutants.…”

Photocatalytic Degradation of Dissolved Phenol by Immobilized Zinc Oxide Nanoparticles: Batch Studies, Continuous Flow Experiments, and Numerical Modeling

“…However, under continuous flow conditions, it would be necessary to separate the photocatalyst particles from the solution, before reusing them, which is a cost-expensive and energy-intensive step. Alternatively, the photocatalyst particles could be immobilized on various types of substrates, with some examples: clay [ 14 ], foams [ 15 , 16 , 17 ], graphene oxides [ 18 ], and borosilicate spheres [ 19 ]. The main disadvantage of such an approach is the reduction of photocatalytic efficiency, due to the decrease of the specific surface area, and mass transfer limitations [ 20 , 21 ].…”