Electrocoagulation using scrap materials for removal of dye with different connection modes and electrode combinations

Abstract

This study analyses the efficiency of electrocoagulation (EC) process by utilizing discarded metal scrap of Iron (Fe) and Aluminium (Al) as electrodes for decolourization of azo dye, Acid Yellow 36 (AY36). Different modes of connection such as mono polar parallel (M-P), mono polar series (M-S) and bi polar series (B-S) were investigated for the performance of percent colour removal and Electrical Energy Consumption (ENC). Within these connections, different electrode arrangements, such as Iron-Aluminium-Iron-Aluminium, Aluminium-Iron-Aluminium-Iron, Iron-Iron-Iron-Iron and Aluminium-Aluminium-Aluminium-Aluminium were analyzed for the dye removal efficiency. The parameters varied during the experimental runs were current density (CD) and pH. M–S showed maximum colour removal of 99.2% with system of mixed electrode Fe–Al–Fe–Al at CD 10 A/m2 and ENC 0.322 Kwh/Kg dye removed. Whereas M-P showed 98.4% colour removal with hybrid system Fe–Al–Fe–Al at CD of 20 A/m2 with ENC 0.209 Kwh/Kg dye removed. B-S showed 99.1% colour removal with mixed electrode system Al-Fe-Al-Fe at CD of 20 A/m2 and ENC 0.86 Kwh/Kg dye removed. Overall, M-S mode gave the maximum colour removal, while M-P gave minimum ENC. The study proved useful in terms of lowering the cost of electrocoagulation by using scrap metal as electrodes and choosing the right electrode combination and connection mechanism.