Facile synthesis, characterization of a MnFe2O4/activated carbon magnetic composite and its effectiveness in tetracycline removal

In this study, MnFe2O4/activated carbon magnetic composites with mass ratio of 1:1, 1:1.5 and 1:2 were synthesized using a simple chemical coprecipitation procedure. A variety of techniques such as X-ray diffractometer, scanning electron microscope, magnetization measurements, BET surface area measurements were used to characterize the structure, morphology and magnetic performance of the prepared composite adsorbents. The results showed that the composites had good magnetic properties, which allowed their convenient magnetic separation from water. Spinel manganese ferrite was found to occur in the magnetic phase and the presence of magnetic particles of MnFe2O4 did not significantly affect the surface area and pore structure of the activated carbon. The magnetic composites were effective for tetracycline (TC) removal from water and the maximal adsorption capacity was 590.5 mmol kg−1 at pH 5.0. The TC adsorption followed pseudo-second-order kinetic model and its removal decreases gradually with an increase in pH value, whereas the removal rate was over 60% even at pH 9.0. The TC adsorption process is endothermic and the increase of temperature is favoring its removal. All these results indicated that the prepared composites had the potential to be used as adsorbents for the removal of TC from water or wastewater.

► The MnFe2O4/activated carbon can be easily separated from water using a magnet.
► The MnFe2O4 did not significantly affect the sorption ability of activated carbon.
► The magnetic composite was effective for tetracycline removal from water.