Persulfate-assisted photocatalytic degradation of eriochrome black T using UV/TIO2/S2O8 2- system: Modeling, analysis, and optimization using response surface methodology

• Main Authors: Bugay, Ninna Felichi Abner, Subagan, Agatha Marie Acerbo
• Format: text
• Language: English
• Published: Animo Repository 2023
• Subjects: Photocatalysis; Titanium dioxide; Persulfates; Response surfaces (Statistics); Biochemistry; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etdb_chem/44; https://animorepository.dlsu.edu.ph/context/etdb_chem/article/1045/viewcontent/2024_Bugay_Subagan_Persulfate_Assisted_Photocatalytic_Degradation_of_Eriochrome_Blac.pdf
• Institution: De La Salle University

The industrial use of dyes in coloring fabrics, food, and cosmetics has resulted in an alarming contamination of water as its effluents retain a large percentage of the dye used. Treatment of dye-contaminated water however proves to be difficult especially when dealing with azo dyes whose azo structures particularly make it resistant to chemical processes. A strategic approach therefore must be employed in removing azo dyes from wastewater. In this study, a binary system, UV/TiO2/S2O8 2- , was investigated for its efficiency in degrading Eriochrome Black T (EBT), an azo dye that presents wide commercial and industrial uses. Initially, photodegradation of EBT were screened using UV/TiO2, UV/PS, and UV/TiO2/PS to determine the most efficient system. The binary system demonstrated to have the highest degradation of 66.19% in aqueous solution. Three operating conditions for the binary system were optimized via response surface methodology (RSM). These were pH, TiO2 dosage, and PS concentration for which a Box-Behnken matrix was designed. This mapped out the effect of different working parameter values on degradation efficiency. Statistical analysis through ANOVA showed that pH (P=0.0000) and TiO2 (P=0.0016) significantly affect degradation efficiency. Moreover, there occurs a significant interaction between PS and TiO2 (P=0.0639) at alpha =0.10 implying that the approach of the binary system in EBT degradation involve a combined effect from the individual mechanisms of the catalyst and the oxidant. Response surface optimization further revealed that within the ranges evaluated in this study, complete removal of EBT through the binary system can be achieved with the following conditions: pH 3, high TiO2 dosage of 2.0 g/L, and low PS concentration of 12.02 ppm.