Removal of manganese ions (Mn2+)‎ from a simulated wastewater by electrocoagulation electroflotation technologies with stainless steel mesh electrodes : process optimization based on Taguchi approach

Abstract EN

This study depicts the removal of Manganese ions (Mn2+) from simulated wastewater by combined electrocoagulation / electroflotation technologies.

The effects of initial Mn concentration, current density (C.D.), electrolysis time, and different mesh numbers of stainless steel screen electrodes were investigated in a batch cell by adopting Taguchi experimental design to explore the optimum conditions for maximum removal efficiency of Mn.

The results of multiple regression and signal to noise ratio (S/N) showed that the optimum conditions were Mn initial concentration of 100 ppm, C.D.

of 4 mA/cm2, time of 120 min, and mesh no.

of 30 (wire/inch).

Also, the relative significance of each factor was attained by the analysis of variance (ANOVA) which indicates that the percentage of contribution followed the order: time (47.42 %), C.D.

(37.13 %), Mesh number (5.73 %), and Mn initial Conc.

(0.05 %).

The electrolysis time and C.D.

were the most effective operating parameters and mesh no.

had a fair influence on Mn removal efficiency, while the initial conc.

of Mn.

had no significant effect in the studied ranges of control factors.

Regression analysis (R2 = 90.16 %) showed an acceptable agreement between the experimental and the predicted values, and confirmation test results revealed that the removal efficiency of Mn at optimum conditions was higher than 99 %.