Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7703426 | Ultrasonics Sonochemistry | 2018 | 9 Pages |
Abstract
This study investigated sulfamethazine (SMT) ultrasound degradation, enhanced by iodine radicals, generated by potassium iodide (KI) and hydrogen peroxide (H2O2) in situ. The results showed that the ultrasound/H2O2/KI (US/H2O2/KI) combination treatment achieved an 85.10â¯Â±â¯0.45% SMT removal (%) in 60â¯min under the following conditions: pHâ¯=â¯3.2, ultrasound power of 195â¯W, initial SMT concentration of 0.04â¯mmol·Lâ1, H2O2 concentration of 120â¯mmol·Lâ1, and KI concentration of 2.4â¯mmol·Lâ1. UV-Vis spectrophotometric monitoring of molecular iodine (I2) and triiodide (I3â) revealed a correlation between the SMT degradation and the iodine change in the solution. Quenching experiments using methanol, t-butanol and thiamazole as radical scavengers indicated that iodine radicals, such as I and I2â, were more important than hydroxyl radicals (HO) for SMT degradation. SMT degradation under the US/H2O2/KI treatment followed pseudo-first order reaction kinetics. The activation energy (Ea) of SMT degradation was 7.75â¯Â±â¯0.61â¯kJ·molâ1, which suggested the reaction was controlled by the diffusion step. Moreover, TOC removal was monitored, and the obtained results revealed that it was not as effective as SMT degradation under the US/H2O2/KI system.
Related Topics
Physical Sciences and Engineering
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Authors
Xiao-yu Yang, Hong Wei, Ke-bin Li, Qiang He, Jian-cang Xie, Jia-tong Zhang,