Synthesis of fly ash based zeolite-reduced graphene oxide composite and its evaluation as an adsorbent for arsenic removal.

A zeolite-reduced graphene oxide (ZrGO) based composite was synthesized to remove arsenic from water. To make a low-cost adsorbent, zeolite was synthesized using an inexpensive waste material; fly ash, which was further used to produce the ZrGO composite. Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Raman spectra were used to characterize the morphology and surface composition of the synthesized materials. Synthesized materials: zeolite, rGO and ZrGO were evaluated as an adsorbent to remove arsenic from water. The results indicated that all three were able to adsorb arsenic from water but the removal efficiency of ZrGO was the best as it was able to bring down the arsenic concentration within the WHO permissible limits. The maximum adsorption capacity for 100 μg/L of initial arsenic concentration was found to be 49.23 μg/g. Results indicate that pseudo second order kinetics describes the arsenic adsorption on ZrGO. Adsorption isotherm study for ZrGO shows best fit for Redlich-Peterson model of adsorption.