Removal of Heavy Metals from Foundry Wastewater using Magnetic Graphene Oxide

This research paper explores the potential of heavy metals removal from foundry effluents using graphene oxide (GO) and magnetic graphene oxide (MGO) as adsorbents.

The preparation of graphene oxide (GO) was performed by the modified Hummers method, while that of magnetic graphene oxide (MGO) was done through coprecipitation methods, with analysis confirming its usefulness in removing metal ions. The influence of contact time, adsorbent dosage, and temperature on the heavy metal removal efficiency was subsequently investigated. The GO and MGO were further characterized using Fourier Transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analyses.

The observed results pointed to GO demonstrating comparatively better removal efficiencies than MGO for Cr, Fe, Pb, Cd, and Zn: 95.40%, 94.00%, 95.80%, 94.2%, and 95.7%, respectively, compared to 88.70%, 87.4%, 90.2%, 90.7%, and 91.2%. Successful synthesis of graphene oxide (GO) and magnetic graphene oxide (MGO) was confirmed by using characterization techniques such as SEM, BET, and FTIR. The morphology and high surface area of GO with a flake-like structure were observed, whereas successful modification of iron nanoparticles onto MGO was observed with a high specific surface area of 1165.220 m2/g and an abundance of surface functional groups.

The heavy metals, which originate from foundry wastes, are removed from the wastewater by using the method of magnetic graphene oxide in this study. Various characterization methods, including SEM, BET, and FTIR, are studied. The parameters affecting the removal of heavy metals are the contact time, adsorbent dosage, and temperature. Contact time increases the opportunity to interact between the adsorbent and metal ions with a longer duration, whereas the number of active sites available to adsorb the heavy metal increases since the adsorbent dosage is higher, thereby increasing the efficiency of removal.

The adsorption could be described in the manner of the Langmuir isotherm and pseudo-second-order kinetics, which depicts MGO's successful removal of heavy metals from foundry wastewater.