Treatment Method with Electrocoagulation in Wastewater that is Dominant with Zinc

The electrocoagulation method was selected for the removal of Zn+۲. The effects of the parameters such as current density, pH, and supporting electrolyte concentration on this method were studied. The Zn+۲ concentration, mixing speed, and temperature were ۲۵۰ mg/L, ۱۵۰ rpm, and ۲۹۳ K in the determination of the optimum pH the results obtained showed that a pH of ۶ provided the highest Zn+۲ removals. A pH of ۶ was taken to be a constant optimum value while studying the effects of current density and supporting electrolyte concentration on removal. Current density values were chosen as ۰.۲۵, ۰.۵۰, ۱.۰۰, and ۱.۵۰ mA/cm۲. Increasing current density increased Zn+۲ removals significantly. Removal of ۴۸.۸۶%, ۷۱.۰۳%, ۸۴.۱۲%, and ۹۷.۳۹% were found for current densities of ۰.۲۵, ۰.۵۰, ۱.۰۰, and ۱.۵۰ mA/cm۲ with an initial concentration of ۲۵۰ mg/L with a reaction time of ۳۰ minutes, respectively. An increase in current density caused an extreme increase in energy consumption. Energy consumption was ۱.۰۶ kW-h/m۳ for a current density of ۰.۲۵ mA/cm۲ with a reaction time of ۳۰ minutes while it was ۱.۹۸, ۳.۴۶, and ۵.۳۱ kW-h/m۳ for a current density of ۰.۵۰, ۱.۰۰, and ۱.۵۰ mA/cm۲ at a pH of ۶, respectively. It was found that the effect of supporting electrolyte concentration on removal efficiency was negative. Aluminum anodes were used in electrocoagulation processes. As supporting electrolyte concentration increased, removal efficiency decreased, and the energy consumption rate increased. It was determined, as the result of the experiments, that Zn+۲ ions can be removed at the rate of ۸۴.۱۲% with a pH of ۶, a ۲۵۰ mg/L Zn+۲ concentration, a ۱۵۰ rpm mixing speed, a temperature of ۲۹۳ K and a current density of ۱.۵۰ mA/cm۲ in an aqueous solution.

کلیدواژه ها:

electrocoagulation ، Zinc ، Heavy metal ، pH ، current density ، Initial Concentration