ABSTRACT
Background: Natural organic matter is the cause of many problems associated with water treatment such as the presence of disinfection by-products [DBPs] and membrane fouling during water filtration. In this study, the performance of the peroxi-electrocoagulation process PEP] was investigated for the removal of humic acids [HAs] from aqueous solutions
Methods: PEP was carried out for the removal of HA using a plexiglas reactor with a volume of 2 L and fitted with iron electrodes and a direct current supply [DC]. Samples were taken at various amounts of pH [2-4], current density [1 and 2A/cm[2]], hydrogen peroxide [50-150 mg/L] and reaction time [5-20 minutes] and then filtered to remove sludge formed during reaction. Finally, the HA concentration was measured by UV absorbance at 254 nm [UV[254]]
Results: Results indicated that increasing the concentration of H[2]O[2] from 50 to 150 mg/L increased HA removal efficiency from 83% to 94.5%. The highest removal efficiency was observed at pH 3.0; by increasing the pH to the alkaline range, the efficiency of the process was reduced. It was found that HA removal efficiency was high in current density 1A/cm[2]. Increasing current density up to 1 A cm[-2] caused a decrease in removal efficiency. Results of this study showed that under the optimum operating range for the process [[current density] = 1A/cm[2], [hydrogen peroxide concentration] = 150 mg/L, [reaction time]= 20 minutes and [pH]= 3.0], HA removal efficiency reached 98%
Conclusion: It can be concluded that PEP has the potential to be utilized for cost-effective removal of HA from aqueous solutions