Efficiency in Ofloxacin Antibiotic Water Remediation by Magnetic Zeolites Formed Combining Pure Sources and Wastes

In this work, red mud (RM) and spinel iron oxide nanoparticles (SPIONs) were added to pure silica/alumina sources (SAs) and fly ash (FA) with the aim of synthesizing and investigating the magnetic behavior of different zeolites. SAs were used to synthesize zeolite with LTA topology (zeolite A) with the addition of both red mud and spinel iron oxide nanoparticles. FA and RM were mixed to synthesize sodalite whereas only FA with the addition of SPIONs was used to form zeolite with FAU-topology (zeolite X). All the synthetic products showed magnetic properties. However, zeolites with spinel iron oxide nanoparticles (zeolites A and X) showed ferromagnetic-like behavior. Sodalite was characterized by a reduction in saturation magnetization, whereas zeolite A with red mud displayed antiferromagnetic behavior. For the first time, all the synthetic products were tested for polluted water remediation by a persistent emerging contaminant, ofloxacin (OFL) antibiotic. The four zeolite types showed good adsorption affinity towards OFL under actual conditions (tap water, natural pH). All materials were also tested for OFL removal in real waters spiked with OFL 10 µg L−1. Satisfactory recoveries (90–92% in tap water, 83–87% in river water) were obtained for the two zeolites synthesized from industrial waste materials.