Electrocoagulation as an Efficient Technique to Remove Dyestuffs from Aqueous Mediums

Abstract

In recent years, attention has been directed towards the application of electrocoagulation (EC) for treatment of wastewater contains toxic and non-biodegradable organic pollutants. It has flexibility in design, operation and the cost. In our study, EC was adopted to treat a lab-synthetic wastewater polluted by methylene blue dye in a batch cell of iron screen anode and two iron cathodes, inner rod and outer cylindrical sheet. The effects of current density, electrolyte concentration and the initial concentration of pollutant on process performance and energy consumption were investigated for a definite process time. The results showed that process efficiency has a direct proportional with applied current density and electrolyte concentration in contrast with the initial dye concentration. Furthermore, for 293 mg/L initial dye concentration and 16 g/L NaCl, removal efficiency reached 93% for current density of 2.67A/m2 compared with 71% at 0.77A/m2 during 15 min process time while 99.5% removal was achieved after 25 min for 2.67A/m2 current density when other parameters remain constant. The optimum operating conditions is calculated from economic point of view based on the requested characteristics of treated water.