The Study of the Performance of Electrocoagulation in Comparison to Electro-Fenton Processes at Decoloration of Methylene Blue Dye from Aqueous Solutions Using Iron Electrode

Methylene blue (MB) is one of the cationic dyes whose presence in textile industries wastewater can be hazardous for ecological systems as well as general health due to aromatic features. The present study aimed to investigate the effectiveness of electrocoagulation (EC) and electro-fenton (EF) processes at decoloration of MB dye from aqueous solutions using iron electrode. This research is a laboratory study carried out as pilot in library scale in the first half of 2014 in Environmental Health Engineering Research Center of Kerman Medical Sciences University. The reactor with general volume of 500 ml containing two Fe-Fe plate electrodes (15×2 cm) connected to a] direct current: (DC) [power supply was used for decoloration of MB dye. The effects of different factors such as contact time, dye concentration, Hydrogen Peroxide concentration (for EF process), used energy, electrolyte, optimal pH, and inter electrode distance were investigated. Data were analyzed using two-way ANOVA. The average efficiency rate of removing MB through EC in optimal conditions (with primary dye concentration of 25 mg/L, pH=7, current density=50 mA, contact time=30 min, inter electrode distance=1 cm) was 93.3%±1.3%, and the removing efficiency rate of EF in optimal conditions (with primary hydrogen peroxide concentration of 100 mmol/L, the primary dye concentration=25 mg/L, pH=5, current density=0.05 A, contact time=30 min, inter electrode distance=1 cm) was obtained 78.9%±0.1% (p=0.003). The results showed that both EC and EF methods were effective in removal of MB dye from aqueous solutions however, with optimization of effective operational factors, EC method could be more efficient.