Research On Benzotriazole Degradation By Fenton Enhanced Ultrasound-Photocatalysis

Benzotriazole is now widely used as additive in various fields. It has been proved that benzotriazole has low biodegradation, thus it will accumulate in the environment and potentially harmful to humans. In this paper we used ultrasound-photocatalysis-Fenton process to treat benzotriazole, its reaction conditions were concerned. We also analyzed the synergy effect of ultrasound-photocatalysis- Fenton and its degradation kinetics.To ultrasound- photocatalysis treatment, the pH and the concentration of the TiO2 were the critical factors for degrading BTA. Under the optimal condition of the pH=7, TiO2=20mg/L, BTA=20mg/L, the remove rate could be reached at 80.59% in 30 min and the reaction rate constant was 0.0516.It was showed that H2O2 could improve the degradation ability of ultrasound- photocatalysis treatment. Under the optimal condition of the pH=3, TiO2=20mg/L, BTA=20mg/L, H2O2=100mg/L, the remove rate could be reached at 100% in 30 min. It was 24.62% higher than the one without H2O2. The reaction rate also increased from 0.0478 to 0.1774. To ultrasound-photocatalysis-H2O2, low concentration of the TiO2 could increase removal efficiency. The ultraviolet would be shielded and scattered when the TiO2 excessive. This decreased the removal rate and reaction rate.The synergistic effect of Fenton and ultrasound-photocatalysis could accelerate the degradation of BTA. When the concentration of BTA was 80mg/L, it could be degraded completely in 10 min. The optimum reaction condition to the ultrasound-photocatalysis-Fenton was pH=3,CH2O2=60mg/L,CFe2+=10mg/L, TiO2=20mg/L. The reaction rate reached at 0.635. It was 17 times higher than the ultrasound-photocatalysis- H2O2 and 83 times higher than the ultrasound-photocatalysis.The removal rate of ultrasound-photocatalysis-Fenton was greater than the sum of singe using ultrasound-photocatalysis and Fenton. The synergy factor S kept bigger than 1 and got its maximum value S=1.52 at 6min.