Influence of anions and cations on the oxidation of basic blue 26 and basic violet 3 dyes by the Fenton process

Abstract

Among the advanced oxidation processes (AOP) used to treat textile effluents, the Fenton process is particularly appreciated for its ability to effectively treat pollutants that are difficult to degrade by other conventional methods, such as synthetic dyes, especially basic or cationic dyes, which present the highest poisoning rates, underscoring the harmful nature of these substances. We conducted an examination in this context, concentrating on the impact of ions on dye degradation at a temperature of 294 K. This is because ions in solution left over from chemicals used during manufacturing processes can have a significant impact on the efficiency of the Fenton reaction, as they can act as catalysts or inhibitors of the reaction. The degradation of cationic, Basic Blue 26 (BB26) and Basic Violet 3 (BV3) dyes at an initial concentration of 10 mg/L by the Fenton process (Fe2+/ H2O2) was studied in this paper. The results showed a discolouration and degradation of 75.5% for BB26 and 45.4% for BV3 after 30 minutes. The effects of monovalent anions (Cl- and NO3-), divalent anions (SO42- and CO32-), and cations (Na+, K+, and Ca2+) on degradation rates were evaluated. The decrease in degradation yield by the presence of Na+, K+ and Ca2+ cations and Cl-, NO3- and SO42-anions for BB26 dye and by the presence of Na+ and Ca2+ cations and Cl- and SO42- anions for BV3 dye was discussed. On the other hand, K+ and NO3- ions have somewhat favoured the yield of BV3 dye degradation, while the presence of carbonate anion (CO32-) increased the degradation rate of our two dyes.