Treatment of pharmaceutical wastewater containing cefazolin by electrocoagulation (EC): Optimization of various parameters using response surface methodology (RSM), kinetics and isotherms study

• Published in: Chemical engineering research & design 2021-12, Vol.176, p.254-266
• Main Authors: Bajpai, Mukul, Katoch, Surjit Singh, Kadier, Abudukeremu, Ma, Peng-Cheng
• Format: Article
• Language: English
• Subjects: Adsorption; Adsorption kinetic & isotherm; Cefazolin (CEZ) removal; Coagulation; Electrocoagulation; Electrocoagulation (EC); Electrodes; Electrolysis; Energy consumption; Industrial wastes; Isotherms; Optimization; Pharmaceutical industry; Pharmaceutical wastewater; Pharmaceuticals; Polynomials; Response surface methodology; RSM optimization; Surface chemistry; Variance analysis; Wastewater treatment; Water filtration; Water treatment
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2021.10.012

[Display omitted] •Optimization using RSM for Cefazolin (CEZ) removal by Electrocoagulation (EC) process.•Pareto analysis was carried out to determine major factors affecting CEZ removal.•CEZ adsorption was a better fit to the pseudo 2nd order kinetic model with R2 > 0.999.•Langmuir isotherms show the best fit when compared with the Freundlich isotherm model.•Electrode and energy consumption and cost analysis of the EC process were also computed. Pharmaceutical wastewaters presently remain as one of the primary roots of environmental pollution. The current study mainly concentrated on removing cefazolin (CEZ) from pharmaceutical wastewater employing the electrocoagulation (EC) process using iron electrodes. The EC experimental conditions were achieved by using response surface methodology (RSM) with an efficiency of 85.65% under optimal working conditions of pH = 8.0, current density (16 mA/cm2), initial CEZ concentration (25 mg/L), and inter-electrode distance (d = 1.0 cm) at an equilibrium electrolysis time of 40 min. The experimental results obtained were in good agreement with the predicted CEZ removal efficiency of 86.7%. Besides, Analysis of variance (ANOVA) revealed that the experimental model was best suited to a second-order polynomial equation, with an R2 value of 0.92. Moreover, the fisher's F-value of 13.67 and low probability value (p < 0.0001) suggest a decent correlation between the experimental and predicted CEZ elimination levels. Additionally, the kinetic adsorption and isotherm results indicated that the model follows pseudo-second-order kinetic adsorption with R2 = 0.999. The Langmuir isotherm with R2 = 0.9508 provides the best match when compared to the Freundlich model. Finally, the energy consumption, electrode dissolution, and operating cost per kg COD eliminated under optimal conditions were calculated to be 0.7395 kW h, 1.513 kg, and 0.89 USD, respectively.