Synthesis and characterization of anthill-eggshell composite adsorbent for removal of hexavalent chromium from aqueous solution.

In this study, adsorption behavior of anthill-eggshell composite (AEC) for the removal of hexavalent chromium (Cr) from aqueous solution was investigated. The raw AEC sample was thermally treated at 864 °C for 4 h and characterized using Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and X-ray fluorescence (XRF) techniques. The effects of adsorption process variables including initial Cr concentration, contact time, and adsorbent dosage on the Cr removal efficiency were investigated using central composite design (CCD) of response surface methodology (RSM).