Photodegradation of naphthol green b using uv/sulfite system: Optimization using response surface methodology

• Main Authors: Caguiat, Juan Miguel E., Tiu, Eldric Roland Untivero
• Format: text
• Language: English
• Published: Animo Repository 2023
• Subjects: Naphthol; Photodegradation; Sulfites; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etdb_chem/27; https://animorepository.dlsu.edu.ph/context/etdb_chem/article/1033/viewcontent/2023_Caguiat_Tiu_Photodegradation_of_naphthol_green_b_using_uv_sulfite_system_Full_text.pdf
• Institution: De La Salle University

The application of sulfite as a radical source in advanced oxidation processes has gained much attention in recent years. Despite many research efforts in the photodegradation of dyes, there are limited studies on sulfite’s photodegradative effects on coordination complex dyes. Naphthol Green B (NGB) is an important industrial and histological dye that is widely used. However, its degradation prior disposal is not a common practice and poses a threat to the aquatic environment. This study seeks to bridge the research gap by determining the effectiveness of sulfite as a radical source for photodegrading NGB. This was done by using Sodium sulfite in a UVC bathed environment. Furthermore, optimization of the degradation efficiency was done via a full factorial response surface methodology, varying the dose of the sulfate radical source, and pH. The photodegradation progress of NGB was monitored via UV-Vis spectrophotometry. The optimum photodegradation conditions were determined using Response Surface Methodology. Using 9 experimental runs, the response was fitted to a 2-factor interaction equation to determine the optimal parameters. Through this work, optimum conditions for photodegrading NGB have been determined to be when sulfite concentration is at 12 mM and pH level of solution is 4. Comparison between the actual photodegradation with a maximum value of 101.02% and average of 96.17%, to the predicted value of 101.70% shows the degree of accuracy in the RSM model. This highlights sulfite potentially serving as an alternative to metal oxides and other catalysts with RSM as a tool for the optimization of photodegradation efficiency. Keywords: Naphthol Green B; Sulfite; Photodegradation; Response surface methodology