Electrochemical oxidation treatment of leather dyeing wastewater using response surface methodology

• Published in: Desalination and water treatment 2019-11, Vol.167, p.302-312
• Main Authors: Oukili, Kaouthar, Loukili, Mohammed
• Format: Article
• Language: English
• Subjects: COD removal; Electrochemical oxidation; Leather dyeing wastewater; Response surface methodology; Specific energy consumption
• ISSN: 1944-3986
• DOI: 10.5004/dwt.2019.24561

The present study investigates the electrochemical oxidation (EO) of real leather dyeing wastewater coming from a local modern tannery in Fez (Morocco). Experiments were performed in an electro-chemical reactor using Ti/Pt anode. Response surface methodology and full factorial central composite design were used to investigate the combined effect of three independent operating parameters considered for the optimization of the EO process: electrolysis time (t), current density (j) and temperature (T). Chemical oxygen demand (COD) removal (Y1) and specific energy consumption (SEC) in kWh/kg of COD removed (Y2) were used as responses to examine the degradation of wastewater. The obtained quadratic model was statistically tested using analysis of variance. The correlation coefficients for the model (R2) were 0.9986 and 0.9830 for COD removal and SEC, respectively. The best conditions for maximum COD removal and minimum specific energy consumption in the present study were t = 2.11 h, j = 18.70 mA/cm2 and T = 286.18 K. Under these optimum conditions, 81.2% of COD removal was observed with energy consumption of 93.85 kWh/kg of COD removal. Fourier transformed infrared spectroscopy analysis was used for the characterization of effluent. Evolution of inorganic ions concentration and changes of turbidity, pH and conductivity of wastewater during the EO process were also followed.