Degradation of norfloxacin by red mud-based prussian blue activating H2O2: A strategy for treating waste with waste

The massive accumulation of red mud (RM) and the abuse of antibiotics pose a threat to environment safety and human health. In this study, we synthesized RM-based Prussian blue (RM-PB) by acid solution-coprecipitation method to activate H 2 O 2 to degrade norfloxacin, which reached about 90% degradation efficiency at pH 5 within 60 min and maintained excellent catalytic performance over a wide pH range (3−11). Due to better dispersion and unique pore properties, RM-PB exposed more active sites, thus the RM-PB/H 2 O 2 system produced more reactive oxygen species. As a result, the removal rate of norfloxacin by RM-PB/H 2 O 2 system was 8.58 times and 2.62 times of that by RM/H 2 O 2 system and PB/H 2 O 2 system, respectively. The reactive oxygen species (ROS) produced in the degradation process included ·OH, ·O 2 - and 1 O 2 , with 1 O 2 playing a dominant role. The formation and transformation of these ROS was accompanied by the Fe(III)/Fe(II) cycle, which was conducive for the sustained production of ROS. The RM-PB/H 2 O 2 system maintained a higher degradation efficiency after five cycles, and the material exhibited strong stability, with a low iron leaching concentration. Further research showed the degradation process was less affected by Cl - , SO 4 2- , NO 3 - , and humic acids, but was inhibited by HCO 3 - and HPO 4 2- . In addition, we also proposed the possible degradation pathway of norfloxacin. This work is expected to improve the resource utilization rate of RM and achieve treating waste with waste.