Degradation of ciprofloxacin by persulfate activation with CuO supported on Mg Al layered double hydroxide

• Published in: Journal of environmental chemical engineering Vol. 9; no. 5; p. 106178
• Main Authors: Zhang, Yaxin, Zhang, Chenhui, Zhou, Zicheng, Wu, Yinsu, Xing, Shengtao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2021
• Subjects: CuO; Mg Al layered double hydroxide; Persulfate activation; Reactive species; Mg Al layered double hydroxide; Persulfate activation; CuO; Reactive species
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2021.106178

CuO is an efficient catalyst for persulfate (PS) activation. However, the leaching of Cu ions is usually serious and the improvement of CuO stability is highly desired for its practical application. Herein, CuO supported on Mg Al layered double hydroxide (LDH) and CuO-LDH composite were synthesized by two-step precipitation and co-precipitation methods, respectively. The leaching of Cu ions was avoided due to the high alkalinity and buffer capacity of LDH. CuO supported on LDH had larger surface area, higher alkalinity and more exposed CuO, thus exhibiting much higher activity than CuO-LDH composite. The sample with the Cu:Mg ratio of 1:1 (Cu4/LDH) exhibited the highest activity and could remove more than 99% of ciprofloxacin within 30 min at pH 4–10. The removal efficiency was still above 94% in the presence of various coexisting substances. Moreover, it showed good stability and reusability. Activated PS generated via the non-radical pathway and SO4−• generated via the radical pathway were the dominant reactive species for ciprofloxacin degradation. The results indicate that Cu4/LDH is a promising catalyst for the removal of organic pollutants with PS activation. [Display omitted] •CuO supported on LDH shows much higher activity than CuO-LDH composite.•CuO supported on LDH can provide more active sites for persulfate activation.•The leaching of Cu ions was avoided due to the high alkalinity of LDH.•It can effectively degrade ciprofloxacin with persulfate over a wide pH range.•Activated persulfate and SO4−• are the dominant active species.