Removal of antibiotics from aqueous solution by using magnetic FeO/red mud-nanoparticles.

In this study, the availability of magnetically separable FeO-red mud nanoparticles (FeO-RM-NPs) for the removal of antibiotics from wastewater was investigated. Disadvantages of red mud and FeO because of difficult separation from aqueous media, agglomeration, and iron leaching were overcome by combining these two materials. After examinating adsorption capability of magnetic FeO-RM-NPs for all studied antibiotic compounds, the experiments were performed by using Ciprofloxacin (CIPRO) as a model compound. Batch experiments were performed to determine the effect of red mud content of synthesized FeO-RM-NPs, pH, reaction time and temperature on the proposed method. The surface morphology, magnetic properties, crystalline structure, thermal stability and Brunauer-Emmet-Teller surface area of the synthesized FeO-RM-NPs were determined. The saturation magnetization of FeO-RM-NPs was determined to be 12.2 emu/g, which is efficient to separate adsorbent from water by using a conventional magnet. For the efficient removal of CIPRO from aqueous media optimum conditions were determined to be 1.5 g red mud for FeO-RM-NPs synthesize, pH 6.0, reaction time 60 min, 3 g/L FeO-RM-NPs dosage at 25 °C. Adsorption was fitted well with pseudo-second-order kinetic model. Equilibrium data were found to be better represented by Freundlich isotherm. n value was 4.32, and K value was 110.15 mg/g for Freundlich isotherm. No important matrix effect was determined for removal of CIPRO from wastewater sample. Film diffusion mechanism controlled adsorption. Magnetically separable FeO-RM-NPs are proposed to be used as efficient adsorbent to remove antibiotics from wastewater sources. Since red mud is a process waste, proposed nanomaterial is a good alternative to commercial adsorbents.