Adsorption and degradation of rhodamine B and bromocresol green by FeOCl under advanced oxidation process

FeOCl has gained popularity as a heterogeneous catalyst for pollutant removal in the Fenton process. However, humidification and adsorption of FeOCl are usually not considered in the process. In this way, the adsorption and Fenton activity using rhodamine B (RhB, cationic compound) and bromocresol green (BCG, anionic compound) as pollutants models, at various pH were studied (2, 3.6, 7, and 10). These studies show a very low adsorption level for RhB only at pH 10; therefore, the removal was due to the Fenton reaction. For BCG, at pH 10 the adsorption is almost zero, and at pH 7 after 240 min the adsorption was almost complete, at pH 7, the dye removal by adsorption is akin to Fenton, therefore, at this pH, the remotion was entirely attributed to adsorption. The solution's removal is the result of the adsorption and Fenton reaction. Additionally, the photocatalytic and photo-Fenton activity of FeOCl was studied by the removal of RhB from a solution at pH 3.6, removing about 84 and 95% of the dye respectively. Under these circumstances, FeOCl is a potential catalyst that could be used for Fenton, photo-Fenton, and photocatalysis. However, the present paper's experimental data shows that its activity depends largely on the percentage of humidity in the catalyst and the ionic charge of the contaminant that will be treated by the catalyst once it has been activated by water vapor. Characterization essays, such as XRD, show a match for the synthesized FeOCl and FT-IR shows a peak change in the-OH groups range. This could be a possible explanation for the apparition of free radicals. & COPY; 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study investigates the adsorption and Fenton activity of FeOCl using rhodamine B and bromocresol green as pollutant models at different pH values. The results show that adsorption and Fenton reactions occur simultaneously, with the extent depending on the pH and the type of pollutant. FeOCl exhibits potential as a catalyst for Fenton, photo-Fenton, and photocatalysis, but its activity is greatly influenced by humidity and the ionic charge of the contaminant.