Novel Fe–Mn oxide/zeolite composite material for rapid removal of toxic copper ions from aqueous solutions

Abstract

In this study, Fe–Mn oxide/zeolite composites were synthesized through the coprecipitation and utilized as an adsorbent for the removal of copper ions from aqueous solution. The physico-chemical properties of the adsorbent were disclosed by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy, automatic micropore analyzer, and surface potential (Zeta) investigation, demonstrating the successful synthesis of the adsorbent. The abundant negative charge and hydroxyl functional group as well as pore structure on the adsorbent surface were very conducive to the removal of copper ions. The effects of adsorbent dosage, the initial concentration of copper ions, the initial pH, and the contact time on adsorption were investigated in batch adsorption experiments. The adsorption followed the pseudo-second-order kinetic model and Langmuir isothermal theory，which showed that the adsorption process was monolayer chemisorption. The complexation reaction of functional groups that contain oxygen, electrostatic attraction, precipitation, and physical adsorption are the primary components of the removal of copper ions mechanism. The results showed that when pH = 6, the leaching concentration of iron and manganese was lower than 0.1 mg/L. In addition, after five cycles of test, the adsorbent could still guarantee 88% of the previous adsorption capacity. The adsorbent exhibits exceptional stability, which is crucial for its use in real water bodies. Thus, this research offered a handy strategy for copper ions removal from aqueous solution.