Treatment of Industrial Saline Wastewater Using Eco-Friendly Adsorbents

Abstract

The wastewater generated from the oil and gas sector is one of the major environmental issues. Varieties of techniques are employed for the treatment of generated wastewater. In this work, an attempt has been made to treat industrial saline wastewater from the oil and gas industry using a combination of synthesized biopolymer, chitosan, with graphene. Chitosan has been synthesized from a bioresource using marine spent. Chitosan was characterized using field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray (EDX) spectroscopy, and thermogravimetric analysis (TGA). Batch experiments were conducted by varying the composition of graphene viz 1, 2, 3, 4, and 5 w/w with respect to a fixed amount of chitosan. The percentage removal efficiency of chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), turbidity, and oil and grease were evaluated. A combination of chitosan and graphene has effectively removed the pollutants present in oil produced water (OPW) compared to chitosan alone. The maximum percentage removal efficiencies of COD (84%), TDS (91%), TSS (80%), turbidity (95%), and oil and grease (99.9%) were obtained for a mixture of chitosan (0.5 g/100 mL) and 5 wt% graphenes. The Freundlich equilibrium isotherm model suited the adsorption data well.