The application of GO-Fe3O4 nanocomposite for chromium adsorption from tannery industry wastewater

Abstract

The discharge of untreated tannery industrial wastewater into the environment has resulted in an adverse effect on the ecosystem and public health. Therefore, this work aimed to remove chromium ions from tannery wastewater through magnetite graphene oxide-nanocomposite (GO-Fe3O4). The experimental design of the study was a full factorial 24 approach using pH, adsorbent dose, contact time, and initial chromium concentrations. The results of FTIR analysis revealed the presence of functional groups such as hydroxyl (3438 cm−1), alcohol (1230 cm−1), aromatic (1467 cm−1), ketone (1629 cm−1), and ether (1120 cm−1). Similarly, GO-Fe3O4 acquired a high surface area of 296.2 m2/g whereas the XRD analysis showed the presence of predominant peaks which are attributed to the magnetite component. Moreover, the SEM image showed many ups and downs on the surface of the adsorbent. These cracks of morphology can create a conducive environment for the interaction of adsorbent and adsorbate. The maximum chromium removal of 95.9% was achieved at the optimum conditions of the initial chromium concentration of 40 mg/L, pH 4, adsorbent dose 1 g/100 mL, and contact time of 120 min whereas the removal of chromium from real tannery wastewater was found to be 90.3%. Based on the adsorption isotherm, the Langmuir model was the best fit for experimental data at R2 0.99, indicating homogeneous and monolayer adsorption. Finally, it can be concluded that GO-Fe3O4 was effective for chromium removal, which is a promising technology to be scaled up at the industrial level for wastewater treatment.