Removal of chemical oxygen demand from slaughterhouse wastewater by electrocoagulation in continuous mode: isothermal, kinetic and adsorption study

Tuesta-Tinoco S.A.; Alcántara-Romero P.L.; Yuli-Posadas R.A.; King-Santos M.E.; Zaldivar-Alvarez W.F.; Rosa-Toro A.L.; Reátegui-Romero W. · Desalination and Water Treatment (2023) · DOI: 10.5004/dwt.2023.30215

Resumen

The objective of this work was to study the effect of hydraulic retention time on the removal efficiency of the chemical oxygen demand (COD), and to evaluate the energy consumption (EC) using the electrocoagulation process in continuous mode with aluminum and iron electrodes. Three volumetric flows of 10, 15 and 22.5 L/h, with hydraulic retention times of 0.5, 0.33 and 0.22 h were studied. The COD and turbidity ranges were 5,400–9,500 mg/L and 2,000–2,600 NTU, respectively. Experimental data were analyzed using kinetic equations: pseudo-first-order and pseudo-second-order models considering both isothermal and non-isothermal conditions. Under optimal conditions, voltage 8 V and hydraulic retention time of 0.33 h, the COD and turbidity removal efficiencies were 62.2% and 99.5%, and 51.2% and 94.5% with aluminum and iron electrodes in a time 60 min, respectively. The results showed that the data fit the pseudo-second-order isotherm model (R2 = 0.997–1.000). The study showed that the EC process strongly depends on hydraulic retention time.

Instituciones: Universidad Nacional Mayor de San Marcos; Universidad Nacional de Ingeniería