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 (HO, HSO, SO, and IO) 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-HO, US-HSO and US-IOdecreased when the pH increased from 6 to 11. The optimal pH for US-SO was 8. Notably, increasing temperature decreased the performance of US, US-HO, and US-IO systems, while it could increase the degradation of BPA in US-SO and US-HSO. The activation energy for BPA decomposition using the US-IO system was the lowest, at 0.453nullkJnullmol, and the synergy index was the highest at 2.22. Additionally, the ΔG# value was found to be 2.11 + 0.29T when the temperature ranged from 25 °C to 45 °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-IO system, the economic analysis yielded 271 kwh m, which was approximately 2.4 times lower than that of the US process.