ABSTRACT
Background and objectives: Cyanide ion is one of the most dangerous compounds for the man. Electrocoagulation process with high efficiency to removing pollutants, than researchers considered a effective process. The aim of this study was to determine the efficiency of electrocoagulation process by aluminum electrodes in cyanide removal from synthetic wastewater using magnesium oxide as a coagulantaid.
Mehods: In this study, a reactor with four aluminum electrodes with dimensions 200 × 20 × 2 mm use of 1 Liter of useful volume of electricity generating device for the removal of cyanide was used. Effect of parameters such as pH[3-9], voltage [10-30 V], the initial concentration of cyanide[50-500 ppm] and different concentrations of magnesium oxide particles [0.1 to 1 mg l] as coagulant aid in the process were investigated.
Results: The results show that the efficiency of EC process at pH 5, voltage of 30 V and an initial concentration of cyanide, 50 mg/lit in 45 minutes, was 80 percent. process will Efficiency by adding coagulant aid. In optimal amounts of coagulant aid [0.1 mg/lit] in electrocoagulation process on the removal of the cyanide 90% was achieved.
Conclusion: Electrocoagulation process is suitable process for the removal of cyanide. Also, Magnesium Oxide as a coagulant aid in this process was good and increase process efficiency.
ABSTRACT
Background: Usually, to produce radical sulfate, persulfate anions can be activated by heat, UV light and transition metals such as iron ions. The purpose of this study was investigation of performance of persulfate activated with iron produced by electrical method using iron anode electrode in degradation of Acid Blue 113 from aqueous solutions.
Materials and Methods: In this study, a lab-scale electrochemical batch reactor equipped with four iron electrodes and a DC power supply was used for removing of Acid Blue 113. The effect of operating parameters such as initial pH, voltage, persulfate and initial Acid Blue 113 concentration were evaluated. Also, the amount of pH changes during the process, the synergistic effect of processes in the system and Acid Blue 113 UV-Vis spectrum analysis in optimal conditions was investigated.
Results: The results showed, initial pH of solution, initial concentration persulfate and applied voltage has a significant effect on dye removal. Dye removal efficiency was higher in acidic condition and decreased with increasing pH, So that, after 2 min of reaction at pH 3, voltage 10 V and 150 mg/L of persulfate, 98% of the dye was removed, at pH 5, 7, 9 and 11, after 2 min of reaction and in the same condition the dye removal efficiency was, 66, 0, 0 and 13.5%, respectively. With increasing voltage from 1 to 10 V, increased the dye removal efficiency. S2O82- at the end of 20 min of reaction, removed 17% of dye, at the same condition, electrochemical process with iron electrode had only 31% efficiency, but, the combination of these two processes could remove 99.8% of dye.
Conclusion: The use of S2O82- anions in an electrochemical reactor with iron electrodes can be increase the efficiency of process. Therefore, using this process can be promising process to industrial wastewater treatment.