Comparison of effects of multiple oxidants with an ultrasonic system under unified system conditions for bisphenol A degradation

Bisphenol A (BPA) as a trace contaminant has been reported, due to widespread use in the plastics industry. This study applied the 35 kHz ultrasound (US) to activate four different common oxidants (H2O2, HSO5-, S2O82-, and IO4-) for BPA degradation. With increasing initial concentration of oxidants, the degradation rate of BPA increased. The synergy index confirmed that a synergistic relationship between US and oxidants. This study also examined the impact of pH and temperature. The results showed that the kinetic constants of US, US-H2O2, US-HSO5- andUS-IO4- decreased when the pH increased from 6 to 11. The optimal pH for US-S2O82-; was 8. Notably, increasing temperature decreased the performance of US, US-H2O2, and US-IO4- systems, while it could increase the degradation of BPA in US-S2O82- and US-HSO5-. The activation energy for BPA decomposition using the US-IO4- systemwas the lowest, at 0.453nullkJnullmol(-1), and the synergy index was the highest at 2.22. Additionally, the Delta G# value was found to be 2.11 + 0.29T when the temperature ranged from 25 degrees C to 45 degrees C. The main oxidation contribution is achieved by hydroxyl radicals in scavenger test. The mechanism of activation of US-oxidant is heat and electron transfer. In the case of the US-IO4- system, the economic analysis yielded 271 kwh m(-3), which was approximately 2.4 times lower than that of the US process.

Automated summary

This study investigates the degradation of bisphenol A (BPA) using 35 kHz ultrasound (US) activated by four different oxidants. The results show that increasing the initial concentration of oxidants enhances the degradation rate of BPA. The study also examines the influence of pH and temperature on the efficiency of the degradation process.