Roghayeh Ganji, Majid Peyravi, Soodabeh Khalili, Mohsen Jahanshahi
The efficient removal of chromium (VI), a hazardous heavy metal ion, has attracted immense attention. In the present work, a novel ceramic membrane was prepared by coating a layer of zero-valent iron@cage-like mesoporous SBA-16 (ZVI@SBA-16) and employed to eliminate chromium (VI) from water. The structure and morphology of synthesized adsorbents and ceramic membranes were evaluated using FTIR, TGA, XRD, EDX, FESEM, and BET. The experimental data were analyzed by means of Langmuir and Freundlich adsorption isotherm models. The maximum adsorption capacity obtained from the Langmuir model was 15.514 mg/g. The highest removal efficiency of 99.2% was attained at pH 2.5. Also, with increasing adsorbent dosage, the removal efficiency increased to above 99.9%. In fact, a significant amount of the adsorbed chromium (VI) converted to the less hazardous chromium (III). The pseudo-second-order model illustrated the favorable association with kinetic experimental results. The improved ceramic membrane (C2) has demonstrated significant elimination of chromium (VI) metal ions in the permeate stream. The C2 exhibited a significantly higher total rejection rate (> 99.9%) in comparison to the untreated membrane.