Study on Application of Electrocoagulation Process to Remove Heavy Metals Lead, Cadmium and Chromium from Water

Subject Areas : Environment Pullotion (water and wastewater)

Farzad Hashemzadeh ^{1 *} , Seyd Mehdi Borghei ²

1 - Ph.D., Environmental Engineering (water and wastewater), Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran *(Corresponding Author)
2 - Prof., Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran.

Received: 2019-06-30 Accepted : 2019-10-02 Published : 2021-06-22

Keywords: Heavy Metals, Aquatic environment, chemical precipitation, electrical coagulation,

Abstract :

Background and Objective: The increasing use of heavy metals for industrial purposes has caused an increment in discharge of these contaminants as industrial wastewater into the environment. Electrocoagulation is a complicated process with several functional mechanisms to remove pollutants. Use of this process as an effective and efficient method to remove heavy metals from water has been recommended.Method: In this research studied parameters are: reaction time, distance between electrodes, initial heavy metal concentration, electrode material, and inlet voltage and pH value. Then, the effect that any of these parameters was investigated. In order to do that a 5.4-liter pilot from plexiglass with length of 20 cm, width of 15 cm and height of 18 cm with electrodes of iron, aluminum and steel having length and width of 15 cm and thickness of 0.2 cm and voltage between 0 to 48 v and a direct current (DC) power supply was used.Findings: removal efficiency by electrocoagulation is directly related to voltage and reaction time increment, so that the best removal efficiency was occurred in voltage of 40 v and reaction time of 40 min. By increasing the initial concentration of metals from 1 to 50 mg/l, removal percentage of lead, cadmium and chromium was decreased. Most amounts of removal percentage were gained using iron– aluminum electrodes in a condition in which the distance between them was 5 cm and pH value was equal to 3.Discussion and Conclusion: Due to the excellent efficiency of the electrocoagulation process in removing heavy metals of chromium, lead and cadmium, the feasibility of removing the metals desired by this process is evaluated and can be used as a novel solution in removing metal ions from industrial effluents.   

References:

1. Hunsom, M., et al. (2005). "Electrochemical treatment of heavy metals (Cu2+, Cr6+, Ni2+) from industrial effluent and modeling of copper reduction." Water Research 39(4): 610-616.


2. Gao, P., et al. (2005). "Removal of chromium (VI) from wastewater by combined electrocoagulation–electroflotation without a filter." Separation and purification technology 43(2): 117-123.


3. Shafaei, A., et al. (2010). "Removal of Mn2+ ions from synthetic wastewater by electrocoagulation process." Desalination 260(1-3): 23-28.


4. Heidmann, I. and W. Calmano (2008). "Removal of Cr (VI) from model wastewaters by electrocoagulation with Fe electrodes." Separation and purification technology 61(1): 15-21.


5. Chen, G. (2004). "Electrochemical technologies in wastewater treatment." Separation and purification technology 38(1): 11-41.


6. Chen, X., et al. (2002). "Investigation on the electrolysis voltage of electrocoagulation." Chemical Engineering Science 57(13): 2449-2455.


7. Parga, J. R., et al. (2005). "Arsenic removal via electrocoagulation from heavy metal contaminated groundwater in La Comarca Lagunera Mexico." Journal of Hazardous Materials 124(1-3): 247-254.


8. Akbal, F. and S. Camcı (2011). "Copper, chromium and nickel removal from metal plating wastewater by electrocoagulation." Desalination 269(1-3): 214-222.


9. Adhoum, N., et al. (2004). "Treatment of electroplating wastewater containing Cu2+, Zn2+ and Cr (VI) by electrocoagulation." Journal of Hazardous Materials 112(3): 207-213.


10. AKHONDI, A., et al. (2012). "The effectiveness of electro coagulation process for the removal of cadmium from water."


11. Holt, P., et al. (1999). "Electrocoagulation as a wastewater treatment." The Third Annual Australian Environmental Engineering Research Event 1000: 41-46.


12. Escobar, C., et al. (2006). "Optimization of the electrocoagulation process for the removal of copper, lead and cadmium in natural waters and simulated wastewater." Journal of environmental management 81(4): 384-391.


13. Alinsafi, A., et al. (2005). "Electro-coagulation of reactive textile dyes and textile wastewater." Chemical engineering and processing: Process intensification 44(4): 461-470.


14. Mahvi, A. H., et al. (2007). "Chromium (Cr) Removal from Aqueous Environments by Electrocoagulation Process Using Aluminum Electrodes." J. of Water and Wastewater 62: 28-34.


15. Fu, F. and Q. Wang (2011). "Removal of heavy metal ions from wastewaters: a review." Journal of environmental management 92(3): 407-418.


16. Ciorba, G. A., et al. (2000). "Correlation between organic component and electrode material: consequences on removal of surfactants from wastewater." Electrochimica Acta 46(2-3): 297-303.


17. Heidmann, I. and W. Calmano (2008). "Removal of Zn (II), Cu (II), Ni (II), Ag (I) and Cr (VI) present in aqueous solutions by aluminium electrocoagulation." Journal of Hazardous Materials 152(3): 934-941.


18. Merzouk, B., et al. (2010). "Using electrocoagulation–electroflotation technology to treat synthetic solution and textile wastewater, two case studies." Desalination 250(2): 573-577.


19. Nouri, J., et al. (2010). "Application of electrocoagulation process in removal of zinc and copper from aqueous solutions by aluminum electrodes." International Journal of Environmental Research 4(2): 201-208.


20. Nekhunguni, P. M. (2017). Sorption of uranium and arsenic onto iron hydroxide/oxide modified zeolite.