Removal of turbidity from tannery wastewater using graphene oxide-ferric oxide nanocomposites as an adsorbent

Water is one of the most essential natural resources in the ecosystem, yet anthropogenic pollution from variety of sources jeopardize this available resource. Turbid tannery effluent is the serious environmental hazard as it interfere photosynthesis of aquatic habitats by obstructing light penetration into the water body. In this research work, an attempt has been made to investigate the potential of graphene oxide (GO)-ferric oxide (MO) nanocomposites for the reduction of turbidity from tannery effluent. Nanocomposites were prepared using facile solution casting method and the dispersibility, material interactions, chemical bonding and morphology of as prepared nanocomposites were determined through UV-Vis spectroscopy, XRD, FT-IR, and TEM analysis, respectively. The effect of pH, adsorbent dosage, and contact time of nanocomposites have been studied for process optimization. At pH 6, about 95% of turbidity was removed by 2 gL(-1) of nanocomposite adsorbent within 30 min. Moreover, both adsorption kinetics and isotherm models were studied during experimentation; pseudo-second-order kinetic equation and Freundlich isotherm model were well suited due to the chemisorption with multilayer adsorption and resulted turbidity removal from tannery wastewater. Here it is worth mentioning that the maximum adsorption capacity in Langmuir isotherm was 67.7 mg/g. Apart from turbidity, other parameters including chemical oxygen demand (COD), salinity and total suspended solids (TSS) was reduced up to 78, 56, and 76%, respectively, after the adsorption process.