Removal of Nitrate from Aqueous Solutions by Batch Electrocoagulation Processes Using Al and Fe Plate Electrodes

Abstract

Nitrate (NO₃^-) is the most common water pollutant in the world, which has a serious threat to human health due to its high solubility in water. Electrocoagulation (EC) process is an impressive method for removal of pollutants from water. This study is focused on the mechanism of NO₃^- removal from aqueous solutions by electrocoagulation process with using aluminum (Al) and iron (Fe) electrodes. Effects of operational parameters such as electrode material, pH and conductivity on the EC process were evaluated. The process carried out by batch method at room temperature (25 ºC). The experimental results for Al–Al (anode-cathode) electrode reveal that nitrate removal efficiencies are 85.94% and 75.29% at 240 min reaction time, for pH of 3 and 10, respectively. Under the same conditions, for Fe-Fe (anode-cathode) electrode combination, the removal efficiencies are 23.1% and 2.66% at pH of 3 and 10, respectively. NO₃^- removal process was carried out at 5V-1A electrical current. According to the results of the study, it was observed that the Al plate electrode was better than Fe plate electrode in NO₃^- removal. In addition, electrocoagulation at low pH was found to be more effective for nitrate removal in the Al-electrode-operated reactor. In addition, pH values and nitrate removal percentages at Al-electrode-operated reactor increased continuously during 240 minutes at low initial pH. On the iron electrode, steady changes were not observed for pH and nitrate removal rates during process period. 

Keywords

• Nitrate,Electrocoagulation,Batch method

References

1. [1] R. Hallberg, Agricultural chemicals in groundwater: extent and implications, American journal of alternative agriculture, 2: 1 (1987) 3-15.
2. [2] E.V.S.P. Rao, K. Puttanna, Nitrates, agriculture and environment, Current science, 79 (2000) 1163-1168.
3. [3] N. Mondal, V. Saxena, V. Singh, Occurrence of elevated nitrate in ground waters of Krishna delta, India. African journal of environmental science and technology, 2: (2008) 265-271.
4. [4] M. M. Emamjomeh, M. Sivakumar, Review of pollutants removed by electrocoagulation and electrocoagulation/flotation processes. Journal of environmental management, 90: (2009) 1663-1679.
5. [5] M. M. Emamjomeh, M. Sivakumar, Denitrification using a monopolar electrocoagulation/ flotation (ECF) process. Journal of environmental management, 91: (2009) 516-522.
6. [6] R. Sadler, B. Maetam, B. Edokpolo, D. Connell, J. Yu, D. Stewart, M. J. Park, D. Gray, B. Laksono. Health risk assessment for exposure to nitrate in drinking water from village wells in Semarang, Indonesia. Environmental pollution, 216: (2016) 738-745.
7. [7] L. El-Hanache, B. Lebeau, H. Nouali, J. Toufaily, T. Hamieh, T. J. Daou, Performance of surfactant-modified *BEA-type zeolite nanosponges for the removal of nitrate in contaminated water: Effect of the external surface. Journal of hazardous materials, 364: (2019) 206-217.
8. [8] X. Rao, X. Shao, J. Xu, J. Yi, J. Qiao, Q. Li, H. Wang, M. Chien, C. Inoue, Y. Liu, J. Zhang, Efficient nitrate removal from water using selected cathodes and Ti/PbO2 anode: Experimental study and mechanism verification, Seperation and purification technology, 216: (2019) 158-165.

9. [9] L. A. Richards, M. Vuachere, A. I. Schafer, Impact of pH on the removal of fluoride, nitrate and boron by nanofiltration/reverse osmosis, Desalination, 261: (2010) 331-337.
10. [10] R. Epsztein, O. Nir, O. Lahav, M. Green, Selective nitrate removal from groundwater using a hybrid nanofiltration-reverse osmosis filtration scheme, Chemical Engineering Journal, 279: (2015) 372-378.
11. [11] Z. Zhang, Y. Han, C. Xu, W. Ma, H. Han, M. Zheng, H. Zhu, W. Ma, Microbial nitrate removal in biologically enhanced treated coal gasification wastewater of low COD to nitrate ratio by coupling biological denitrification with iron and carbon microelectrolysis, Bioresource technology, 262: (2018) 65-73.
12. [12] H. Liu, Z. Chen, Y. Guan, S. Xu, Role and application of iron in water treatment for nitrogen removal: a review, Chemosphere, 204: (2018) 51–62.
13. [13] D. Reyter, D. Belanger, L. Roue, Nitrate removal by a paired electrolysis on copper and Ti/IrO2 coupled electrodes - influence of the anode/cathode surface area ratio, Water Research, 44: (2010) 1918-1926.
14. [14] N. Arahman, S. Mulyati, M. R. Lubis, R. Takagi, H. Matsuyama, Removal profile of sulfate ion from mix ion solution with different type and configuration of anion exchange membrane in elctrodialysis, The journal of water process engineering 20: (2017) 173-179.
15. [15] A. Bhatnagar, M. Sillanpää, A review of emerging adsorbents for nitrate removal from water, Chemical engineering journal, 168: (2011) 493-504.
16. [16] A. Teimouri, S. G. Nasab, N. Vahdatpoor, S. Habibollahi, H. Salavati, A. N. Chermahini, Chitosan/zeolite Y/nano ZrO2 nanocomposite as an adsorbent for the removal of nitrate from the aqueous solution, International Journal of Biological Macromolecules, 93: (2016) 254-266.
17. [17] G. Mendow, A. Sanchez, C. Grosso, C.A. Querini, A novel process for nitrate reduction in water using bimetallic Pd-Cu catalysts supported on ion exchange resin, Journal of environment chemical engineering, 5: (2017) 1404-1414.
18. [18] S. Tyagi, D. Rawtani, N. Khatri, M. Tharmavaram, Strategies for Nitrate removal from aqueous environment using nanotechnology: A Review, Journal of water process engineering, 21: (2018) 84-95.
19. [19] Z. Zhang, Y. Han, C. Xu, W. Ma, H. Han, M. Zheng, H. Zhu, W. Ma, Microbial nitrate removal in biologically enhanced treated coal gasification wastewater of low COD to nitrate ratio by coupling biological denitrification with iron and carbon microelectrolysis, Bioresource technology, 262: (2018) 65-73.
20. [20] H. Liu, Z. Chen, Y. Guan, S. Xu, Role and application of iron in water treatment for nitrogen removal: a review, Chemosphere, 204: (2018) 51-62.
21. [21] E. Lacasa, P. Canizares, C. Sáez, F. J. Fernández, M. A. Rodrigo, Removal of nitrates from groundwater by electrocoagulation Chemical Engineering Journal, 171: (2011) 1012- 1017.
22. [22] W. Tang, P. Kovalsky, D. He, T. D. Waite, Fluoride and nitrate removal from brackish groundwaters by batch-mode capacitive deionization, Water Research, 84: (2015) 342-349.
23. [23] Z. Zhang, A. Chen, Simultaneous removal of nitrate and hardness ions from groundwater using electro deionization, Separation and purification technology, 164: (2016) 107-113.
24. [24] Y. L. Deng, Y. J. Ruan, S. M. Zhu, X. Y. Han, Z. Y. Ye, G. Liu, M. M. Shi, The impact of DO and salinity on microbial community in poly(butylene succinate) denitrification reactors for recirculating aquaculture system waste water treatment, AMB express, 7: (2017) 113-120.
25. [25] Q. Song, M. Li, L. Wang, X. Ma, F. Liu, X. Liu, Mechanism and optimization of electrochemical system for simultaneous removal of nitrate and ammonia, Journal of hazardous materials, 363: (2019) 119-126.
26. [26] H. I. Uzun, E. Debik, Economical approach to nitrate removal via membrane capacitive deionization, Separation and purification technology, 209: (2019) 776-781.
27. [27] K. Govindan, M. Noel, R. Mohan, Removal of nitrate ion from water by electrochemical approaches, Journal of water process engineering, 6: (2015) 58-63.
28. [28] P. K. Holt, G. W. Barton, C. A. Mitchell, The future for electrocoagulation as a localized water treatment technology, Chemosphere, 59: (2005) 355-367.
29. [29] K. S. Hashim, A. Shaw, R. A. Khaddar, M. O. Pedrola, D. Phipps, Energy efficient electrocoagulation using a new flow column reactor to remove nitrate from drinking water e Experimental, statistical, and economic approach, Journal of environmental management, 196: (2017) 224-233.
30. [30] N. S. Kumar, S. Goel, Factors influencing arsenic and nitrate removal from drinking water in a continuous flow electrocoagulation (EC) process, Journal of hazardous materials, 173: (2010) 528-533.
31. [31] M. Kobya, S. Delipinar, Treatment of the baker’s yeast wastewater by electrocoagulation, Journal of hazardous materials, 154: (2008) 1133-1140.
32. [32] M. Majlesi, S. M. Mohseny, M. Sardar, S. Golmohammadi, A. Sheikhmohammadi, A. Improvement of aqueous nitrate removal by using continuous electrocoagulation/electroflotation unit with vertical monopolar electrodes, Sustainable environment research, 26: (2016) 287-290.
33. [33] C. B. Shivayogimath, C. Watawati, Treatment of solid waste leachate by electrocoagulation technology. International journal of engineering research and technology, 2: (2013) 266-269.
34. [34] R. Jotin, S. Ibrahim, N. Halimoon, Electrocoagulation for removal of chemical oxygen demand in sanitary landfill leachate. International journal of environmental science, 3: (2012) 107-110.
35. [35] K. Bensadok, S. Benammar, F. Lapicque, G. Nezzal, Electrocoagulation of cutting oil emulsions using aluminium plate electrodes, Journal of hazardous materials, 152: (2008) 423-430.
36. [36] U. T. Un, A. S. Koparal, U. B. Ogutveren, Fluoride removal from water and wastewater with a batch cylindrical electrode using electrocoagulation, Chemical engineering journal, 223: (2013) 110-115.