Effect of Dye and NaCl Concentrations on Methylene Blue Dye Removal by Electrocoagulation

Abstract

This study investigated the influence of two significant operating factors of dye and NaCl concentrations on dye removal efficiency by electrocoagulation (EC) process. The methylene blue (MB) was represented dye molecule containing in the wastewater, whereas the NaCl was playing a role as electrical conductivity for promoting chemical reactions. The initial concentrations of MB and NaCl were varied from 3 to 60 mg/L and 0.10 to 1.00 g/L respectively to find the best condition for dye removal. The results revealed that the maximal dye removal of 91% was observed at MB concentration of 45 mg/L and NaCl of 0.50 g/L. The higher dye concentration (i.e., 60 mg/L) and lower dye concentration (i.e., 3, 15 and 30 mg/L) were affected on decreasing the dye removal. Similarly, the higher NaCl concentration (i.e, 0.75 and 1.00 g/L) and lower NaCl concentration (i.e. 0.10 and 0.25 g/L) had negative impacts on dye removal. Furthermore, the actual batik wastewater was preliminary treated by EC process; the COD was decreased from 3720 mg/L in the initial concentration to 320 mg/L after 60 min. In addition, the dye removal by EC process can be enhanced by controlling other parameters such as submerged surface area, applied current density and pH which will be further studied prior to imply as treatment process for textile industry