Photodegradation of phenol by UVC-activated persulfate in the presence of Fe (III) as a catalyst

Summary

In the process of executed research, the photocatalytic degradation of phenol was studied using deep oxidation with the use of sulfate radicals (SR-AOPs-Sulfate Radical-based Advanced Oxidation Processes). In particular, the {UVC/PS/Fe(III)} combination was used and compared with direct photolysis, {UVC/PS} and {PS/Fe(III)}. The results showed that the {UVC/PS/Fe(III)} treatment had the highest initial reaction rate and removal efficiency. After 120 minutes of reaction, the {UVC/PS/Fe (III)} oxidation system provided for 74% phenol removal. The effect of pH, persulfate concentration, Fe (III) concentration, and initial phenol concentration on the removal efficiency in the {UFS/PS/Fe(III)} system was also investigated. The optimum phenol removal efficiency is achieved at pH 4, whereas, increasing alkalinity reduces the removal efficiency. In addition, an increase in the concentration of persulfate to 10 mmol improved the removal efficiency; however, an excessive dose of persulfate had a negative effect on the phenol degradation. Similarly, the effective degradation of phenol is achieved by increasing the concentration of ferric ions to 5 mmol at a lower initial concentration of phenol. The data obtained indicate that the presence of ferric ions promotes the formation of radicals in situ in the {UVC/PS/Fe(III)} system, which leads to a significant improvement in the photocatalytic degradation of phenol. Overall, the study highlights the potential of the {UVC/PS/Fe(III)} system for phenol-contaminated wastewater treatment prior to discharge to water bodies.

Key words

wastewater , photocatalytic degradation of phenol , UVC-activated persulfate , deep oxidation with sulfate radicals