A Comparative study on removal of reactive black 5 using Electrocoagulation and Electrocoagulation/Flotation Processes in aqueous solution

Nowadays, synthetic azo compounds as environmental pollutants are widely used in different application. In this research the treatability of effluent polluted with reactive black 5 azo dye using electrocoagulation (EC) and electrocoagulation/ flotation (ECF) processes with aluminum electrodes investigated in a lab scale batch experimental reactor.
In present study an electrocoagulation flotation reactor in a lab scale to an approximate volume of 1 liter which is equipped with four Al0Al electrodes with dimensions of 200*20*2 mm was proposed. The effects of operational parameters such as initial pH, current density, contact time, initial dye concentrations and flotation were evaluated.
Findings: The results indicated that the highest dye removal rates in the EC process were observed in natural pH of solutions, 12.71 mA/Cm2 current density and 100 mg/l initial dye concentration at 30 min contact time. In these conditions up to 81% of dye was removed in the EC process. Based on the result obtained in this study, it was found that much higher dyes removal could be achieved by ECF (86%) process than that by EC process in the same conditions.
EC and ECF processes using aluminum electrodes for dye removal could be a promising process.