Optimization of Electrocoagulation via Response Surface Methodology to Remove Ciprofloxacin from Aqueous Media

The response surface statistical model developed via the central composite design (CCD) is a tool for optimizing manufacturing processes. Phrmaceutical plants depend on many such processes and i is essential to remove medicinal compounds from their effluents before they are discharged into the environment. The objective of the present study was to employ the response surface model for the optimization of the removal of the pharmaceutical compound ciprofloxacin from aqueous media via the electrochemical coagulation process. In this study, a reactor containing two iron electrodes used as the anode and two titanium ones used as the cathode was employed to remove ciprofloxacin from municipal effluents. The electrodes were connected in a monopolar fashion to a DC power supply. Parameters such as pH (4‒8), current (0.5‒1.5 A), initial ciprofloxacin concentration (15‒40 mg/L), and reaction time (15‒30 min) were introduced into the Design Expert software as the main design parameters. FT-IR analysis was conducted and SEM images were prepared while COD removal and changes in UV-VIS spectrum were determined under optimum conditions. Process modeling was accomplished using the response surface methodology (RSM) which is a statistical model for process optimization drawing upon central composite design (CCD). Modeling results showed that process efficiency was affected by the above parameters and that the optimum conditions for a process efficiency of 85.91% at an initial CIP concentration of 15mg/L would include pH=7.68, a current of 1.5 A, and a reaction time of 30 min. Under these conditions, COD removal efficiency would be 64%. FT-IR analysis and SEM images indicated changes during the process. Wavelength scanning also indicated reducing concentration of the contaminant due to mineralization. The results of the study indicate that optimization by RSM reduces the number of tests required and enhances their accuracy. It was also found that electrocoagulation has a high CIP and COD removal efficiency which makes it capable of being successfully exploited for the removal of organic pollutants from effluents before their discharge into the environment