Novel insights into the mechanism of periodate activation by heterogeneous ultrasonic-enhanced sludge biochar: Relevance for efficient degradation of levofloxacin

• Published in: Journal of hazardous materials 2022-07, Vol.434, p.128860-128860, Article 128860
• Main Authors: He, Liuyang, Yang, Shangding, Shen, Shitai, Ma, Yongfei, Chen, Yulin, Xue, Jianming, Wang, Jia, Zheng, Li, Wu, Li, Zhang, Zulin, Yang, Lie
• Format: Article
• Language: English
• Subjects: Charcoal; Heterogeneous; Levofloxacin; Periodate; Periodic Acid; Sewage; Sludge biochar; Ultrasonic; Ultrasonics; Water; Water Pollutants, Chemical - analysis
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.128860

In this study, a novel heterogeneous ultrasonic (US)-enhanced sludge biochar (SBC) activated periodate (PI) system was established and explored for the rapid removal of levofloxacin in the aqueous environment. This study focused on the mechanisms of US-enhanced SBC co-activation of PI for levofloxacin degradation. The results indicated that US and SBC exhibited a remarkable synergistic reinforcing activation effect on PI compared to single PI activation systems. The SBC/US/PI system achieved approximately 95% of levofloxacin removal, 51.5% of TOC removal, and 22% of dechlorination rate within 60 min with virtually no heavy metals released into the water matrix. In addition, the acute ecotoxicity of the solutions treated with the SBC/US/PI system was substantially reduced. The presence of IO3•, •OH, 1O2 and O2•- were identified in the SBC/US/PI system using quenching experiments and EPR technology while •OH and 1O2 were the predominant reactive species. Mechanistic studies have suggested that the cavitation effect of ultrasonic improved the dispersion and mass transfer efficiency of SBC and accelerated the desorption process of SBC. Possible pathways of levofloxacin degradation were proposed. This study provides a novel and promising strategy for the efficient removal of emerging contaminants such as antibiotics from the water matrix. [Display omitted] •Ultrasonic markedly enhances the activation effect of sludge biochar on periodate.•SBC/US/PI system can remove LVF efficiently under a broad pH range.•SBC/US/PI system exhibits outstanding reusability without notable metal leaching.•Possible mechanisms and degradation pathways of LVF degradation were proposed.