Institute of the Industrial Ecology Problems of the North at the Kola Science Centre, Russian Academy of Sciences, Apatity, Russia:

A. V. Svetlov, Research Fellow at the Laboratory of Industrial Ecology, Candidate of Technical Sciences, e-mail: antonsvetlov@mail.ru

Melnikov Research Institute of Comprehensive Exploitation of Mineral Reserves, Russian Academy of Sciences, Moscow, Russia:
V. G. Minenko, Lead Researcher, Candidate of Technical Sciences, e-mail: vladi200@mail.ru
A. L. Samusev, Senior Researcher, Candidate of Technical Sciences

Kola MMC JSC, Zapolyarnyy, Russia:
E. M. Salakhov, Chief Manager of Environmental Control, Monitoring and Reporting Department, Environmental Safety Center

Nearly 9.5 million m³ of water is drained annually from the Severnyi Mine operated by JSC Kola MMC. The mine water treatment plant with a capacity of 500 m³/h is composed of a mine water receiver tank, a mixer, and primary treatment facilities — two interconnected settling ponds, high-rate filters, a chemicals feed plant, a pumping station feeding wash water to the tower, a chlorinator plant, and a wash water tank. Wash water from the filters and sediment from the clarifiers is discharged into the concentrator’s tailings sump. Environmental monitoring data collected by Kola MMC JSC since 2010 indicate that the mine water from the Severny Mine discharged into the rivers Bystraya and Haukilampijoki does not comply in terms of chemistry with the applicable environmental and health standards for suspended solids, sulfates, nickel, nitrogen compounds, and petroleum products. Previously, a process was proposed for cleaning the water discharged from the Severny Mine based on the methods of chemical precipitation, flocculation, and coagulation. However, chemical coagulation requires the addition of multiple reagents (alkali, acid, coagulant, flocculant), which leads to an increase in water salinity during the treatment process and generates a large amount of toxic waste (sediment containing organic compounds and aluminum, etc.), polluting the environment and resulting in significant recycling and disposal costs. In addition, the low temperature of the mine water (especially in winter) hinders coagulation based on aluminum salts, requiring non-conventional water treatment methods. Comparative tests were carried out of wastewater treatment processes based on chemical and electrochemical coagulation using the mine water of the Severny Mine of Kola MMC JSC. It was found that the efficiency of the coagulating chemical (i. e. polyaluminum chloride) is in strong dependence on the temperature and the pH of the initial mine water, and the process relies on the use of a broad range of reagents driving up the operating costs. The use of the electrochemical coagulant instead of polyaluminum chloride ensured a highly efficient process of mine water treatment. Thus, the results reached for certain parameters are in compliance or close to being in compliance with the maximum permissible concentrations applicable to fisheries. The experiments demonstrated the advantages of the electrocoagulation method, providing both a reduction in the reagent feed rate and a higher degree of water purification in terms of copper, nickel, nitrogen compounds, suspended solids, chromaticity, biochemical oxygen demand, and petroleum products.

1. Younger P. L., Banwart S. A., Hedin R. S. Mine Water. Hydrology, Pollution, Remediation. Environmental Pollution. Dordrecht: Springer, 2002. Vol. 5. 442 p.
2. Fu F., Wang Q. Removal of heavy metal ions from wastewaters: A review. Journal of Environmental Management. 2011. Vol. 92. pp. 407–418.
3. Wolkersdorfer C., Lopes D. V., Nariyan E. Intelligent mine water treatment — recent international developments. Sanierte Bergbaustandorte im Spannungsfeld zwischen Nachsorge und Nachnutzung. WISSYM 2015. 2015. pp. 63–68.
4. Klein R., Tischler Ju. S., Mühling M., Schlömann M. Bioremediation of mine water. Advances in Biochemical Engineering Biotechnology. Berlin, Heidelberg : Springer, 2014. Vol. 141. pp. 109–172.
5. Panshin A. M., Viduetskiy M. G., Purgin A. P., Maltsev V. A., Garifulin I. F. Development of technology of mine waters purification using pneumatic columnar flotation machine. Non-Ferrous Metals. 2014. No. 2. pp. 11–15.
6. Lesnikova E. B., Artemova N. I., Lukicheva V. P. Mine water purification with the use of humic preparations. Solid Fuel Chemistry. 2009. Vol. 43, No. 6. pp. 387–390.
7. Banks D., Younger P. L., Arnesen R.-T., Iversen E. R., Banks S. D. Minewater chemistry: the good, the bad and the ugly. Environmental Geology. 1997. Vol. 32, No. 3. pp. 157–174.
8. Skousen J., Zipper C. E., Rose A., Ziemkiewicz P. F., Nairn R., McDonald L. M., Kleinmann R. L. Review of passive systems for acid mine drainage treatment. Mine Water and the Environment. 2017. Vol. 36, No. 1. pp. 133–153.
9. Kaartinen T., Laine-Ylijoki J., Ahoranta S., Korhonen T., Neitola R. Arsenic removal from mine waters with sorption techniques. Mine Water and the Environment. 2017. Vol. 36, No. 2. pp. 199–208.
10. Akinwekomi V., Maree J. P., Wolkersdorfer C. Using calcium carbonate/hydroxide and barium carbonate to remove sulphate from mine water. Mine Water and the Environment. 2017. Vol. 36, No. 2. pp. 264–272.
11. Jafari M., Abdollahzadeh A. A., Aghababaei F. Copper ion recovery from mine water by ion flotation. Mine Water and the Environment. 2017. Vol. 36, No. 2. pp. 323–327.
12. Agboola O., Mokrani T., Sadiku E. R., Kolesnikov A., Olukunle O. I., Maree J. P. Characterization of two nanofiltration membranes for the separation of ions from acid mine water. Mine Water and the Environment. 2017. Vol. 36, No. 3. pp. 401–408.
13. Pestryak I. V. Substantiation and development of effective conditioning techniques for the recycled water of concentrator plants. Gornyy informatsionno-analiticheskiy byulleten. 2018. No. 7. pp. 153–159.
14. Pestriak I., Morozov V., Erdenetuya O. Modelling and development of recycled water conditioning of copper-molybdenum ores processing. International Journal of Mining Science and Technology. 2019. Vol. 29. pp. 313–317.
15. Chen G. Electrochemical technologies in wastewater treatment. Separation and Purification Technology. 2004. Vol. 38. pp. 11–41.
16. Mollah M., Schennach R., Parga J., Cocke D. Electrocoagulation (EC) — science and applications. Journal of Hazardous Materials. 2001. Vol. 84. pp. 29–41.
17. Electrocoagulation. Technology overview. 2010. Interstate Technology & Regulatory Council, Mining Waste Team. Available at: https://www.itrcweb.org/miningwaste-guidance/to_electrocoagulation.pdf.
18. Oncel M. S., Muhcu A., Demirbas E., Kobya M. A comparative study of chemical precipitation and electrocoagulation for treatment of coal acid drainage wastewater. Journal of Environmental Chemical Engineering. 2013. Vol. 1, No. 4. pp. 989–995.
19. Kuokkanen V., Kuokkanen T., Rämö J., Lassi U. Recent applications of electrocoagulation in treatment of water and waste-water – A review. Green and Sustainable Chemistry. 2013. Vol. 3. pp. 89–121.