HUMBERTO RUBÍ-JUÁREZ, CARLOS BARRERA-DÍAZ AND FERNANDO UREÑA-NUÑEZ
Abstract
The oily matter elimination from car wash wastewater through an electro coagulation process followed by adsorption and simultaneous electro coagulation-adsorption were evaluated. COD removal was 78, 71 and 76% using aluminum, zinc and copper electrodes, respectively, while the Turbidity reached 92, 78 and 90% after 60 minutes of electro coagulation. After adsorption with Commercial GAC using a dose of 22.5 g/L, percentages of 99, 97 and 98% were reached, respectively. The coupling between electrocoagulation and GAC at concentrations of 7.5, 15 and 22.5 g/L allowed COD to decrease to 86, 91 and 94% and turbidity to 96, 97 and 98% using aluminum electrodes. The order in which the models best fitted the data was: Jovanovic>Langmuir>Freundlich>Temkin for adsorption isotherms and pseudo second order>Avrami-Erofeev>Elovich>pseudo first order>intraparticle diffusion for adsorption kinetics. Finally, the parameters in treated water were lower than limits set by the Mexican official standard, even enabling water reuse for washing of automobilesâ chassis.