Exclusion of Pharmaceutical Compounds by UA Assisted EC Process

Abstract

The toxicity of pharmaceutical pollutants affects aquatic life as well as the environment on all levels of the natural hierarchy. Therefore, to maintain the natural environment it is crucial to exclude pharmaceutical compounds, such as ofloxacin (OFX), sunset yellow (SY), and tartrazine (TRT) from aqueous systems. In this study, a green nanoadsorbent (CS@GOn) will be prepared by the electrostatic interaction of chitosan (CS) and graphene oxide (GO). Characterization using scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and Fourier-transform Infrared (FTIR) spectroscopy analysis of CS@GOn will be performed and the cross-linking of CS with GO will be confirmed. Further, batch electrocoagulation (EC) and ultrasonication adsorption (UA) assisted processes will be performed individually and as hybrid systems for the removal of OFX, TRT, and SY from aqueous solutions. The optimum conditions will be evaluated by considering the minimum operating cost (OC). In EC processes, based on the economic >70% removal of OFX, TRT, and SY were achieved at optimum conditions of pH 7, 10 min, and OFX 200 mg/L. However, in UA processes, >83% OFX, TRT, and SY were removed under the same conditions. In hybrid EC and UA processes, >98% OFX, TRT, and SY were removed at the optimized conditions (pH 7, 10 min, and OFX 200 mg/L, dose 0.1 g/200 mL, and 25°C). CS@GOn was reused up to five times after the regeneration. Compared with EC and UA individual processes, hybrid EC and UA processes were more effective for the removal of OFX, TRT, and SY. A feasibility study of EC + UA process will be explored for the removal of chemical oxygen demand (COD) from actual sewage effluent and 95% removal was achieved for a 10 min reaction time of EC and UA. This study provides a promising hybrid EC and UA process with CS@GOn that has excellent biocompatibility, reusability potential, and could be used in a wide range of industrial effluents.