Magnetic solid phase adsorption of ceftiofur sodium in water by deep eutectic solvent modified banana peel-MnFe2O4 biochar

Abstract

Magnetic solid phase adsorption separation (MSPA) technology is an efficient and convenient separation method, which can simplify the separation step and shorten the separation time. It has wide application value in the purification of antibiotic pollutants in water. In this study, a novel magnetic biochar adsorbent (DES₁@MnFe₂O₄-BBC) with strong selectivity and high adsorption capacity was synthesized. It was composed of banana peel as the biochar source, Mn/Fe bimetallic oxide as the magnetic source and deep eutectic solvent (DES) as the functional monomer. The physicochemical properties of DES₁@MnFe₂O₄-BBC were systematically characterized by nitrogen adsorption–desorption, synchronous thermal analyzer, vibrating sample magnetometer, X-ray diffractometer, X-ray photoelectron spectroscopy, and field emission electron microscopy. The adsorption conditions were optimized by the single-factor optimization method. Also, under the optimal adsorption conditions, the maximum adsorption capacity of DES₁@MnFe₂O₄-BBC for ceftiofur sodium was 75.01 mg·g⁻¹. The test of adsorption thermodynamics and kinetics illustrated that the Langmuir isotherm adsorption model and pseudo-second-order kinetic equation were suitable well with the adsorption system established in this article. Adsorbent regeneration cycle experiment revealed that the DES₁@MnFe₂O₄-BBC was an efficient and reusable adsorbent. In the end, all research proves the novel magnetic adsorbent synthesized in this study can provide a new idea for the removal of antibiotics in water.