Tetracycline adsorption on the composite magnetite-bentonite

Abstract

In this research, magnetite-bentonite composites were synthesized as a unique sorbent for the delivery of tetracycline. The introduction of magnetite particles into bentonite structure is based on X-ray phase analysis. Adsorption of tetracycline on bentonite surface and magnetite-bentonite composite was studied. It is shown that maximum adsorption of tetracycline on the surface of bentonite and composite magnetite-bentonite is 84.2 and 71.1 mg/g, respectively. The dependence of adsorption on pH and time was established. The increase in the adsorption value on the surface of the composite magnetite-bentonite with increasing pH is due to the dissociation in alkaline medium of bentonite silicate groups in the composite content. Electrostatic interaction occurs between the amino acids of tetracycline and negatively charged silicate groups in bentonite, oxygen atoms and OH groups form hydrogen bonds with SiOH groups of bentonite and Fe-O groups of magnetite. Electrostatic interactions and H-bonds were determined as the main forces providing adsorption.