Heavy Metals in Glaciers and River Water of the Basin of the Bezengi Cherek River During Intense Graciation Degradation

Introduction. Glaciers in mountainous areas are accumulators of atmospheric moisture and at the same time one of the main sources of food for the main rivers of the Caucasus and are promising sources of fresh water. This is especially true for the rivers of the basin of the largest glaciation unit - Bezengi. But besides the shortage of fresh water, there is another problem: its quality. Purpose of the work: to give a spatial and temporal characteristic of the distribution of the concentration of heavy metals (HM) in the Bezengi and Mizhirgi glaciers, as well as in the river. Cherek Bezengi in the period from the beginning of the XXI century.

Materials and methods of research. In this work, a comparative analysis of the concentrations of HM contained in glaciers and river waters of the river basin was carried out. Cherek. Sampling was carried out starting from the source of the Cherek River, during periods with different hydrological regimes. When sampling water, the temperature of air, water and transparency were recorded. Samples were preserved with nitric acid on the day of sampling. The concentrations of the following HMs, modern priority environmental pollutants, were determined: Cr, Ni, Mo, Mn, Pb, Zn, Ag, Cu, Cd. The determination of HM content in ice samples and river waters was carried out from 2003 to 2010 at the High Mountain Geophysical Institute by the method of emission spectral analysis. Sample analysis 2012–2021 were produced by the atomic absorption method on an MGA-915 spectrometer.

Results and discussion. It was found that the chemical composition of water at the headwaters of the river and in the tongue of glaciers is closer than in the lower reaches of the river. HM concentrations at the beginning of the 21st century significantly exceed HM concentrations in recent years. In winter samples 2018−2019. in many samples, the content of some HMs is below their detection limit (L/L). The latest series of samples cover several points on the river. Cherek Balkar and after their confluence and the formation of the river. Cherek.

Conclusions. The content of HMs in one of the most powerful glaciation centers in the Caucasus, Bezengi, was studied. The results obtained make it possible to judge the migration of HMs in the system of snow-firn-ice thickness - melt waters of glacier-fed rivers at their sources. For river waters of the river basin. Cherek Bezengi and the Bezengi and Mizhirgi glaciers in the last series of winter sampling samples (2018-2019) there is a decrease in the concentration of HMs. This is due to the fact that the content of HMs in winter sampling samples is close to their content in solid sediments. And for other series of samples, the content of HMs is determined by the melting of avalanches and ice falls from the slopes, which constitute a significant part of the balance of the Bezengi and Mizhirgi glaciers and contribute to an increase in the concentration of HMs in melt waters.

1. Atabieva F.A., Gekkieva S.O. Assessment оf the Content Level оf Manganese and Molybdenum Compounds in the Water оf the Rivers оf the River Basin Terek // Science. Innovations. Technologies. 2020. No. 4. P. 161–170.

2. Atabieva, F.A., Cherednik, E.A., Otarova, A.S. Spatial-time variability of the level of heavy metal compounds in the water of the Malka and Baksan rivers // Science. Innovations. Technologies. 2021. No. 3. P. 119–132.

3. Burtsev I.I., Burtseva L.V., Vorobieva T.I. Method of determination of microelements in natural objects during geophysical research. Tr. Alpine Geophysical Institute, 1980. Issue. 45. P. 51–66.

4. Gachechiladze G.A. Influence of glacial waters on the formation of the chemical composition of the waters of mountain rivers // Meteorology and hydrology. 1986. No. 1. P. 94–100.

5. Kotlyakov V.M. Glaciological dictionary. L.: ed. Gidrometeoizdat, 1984. 526 p.

6. Katalog lednikov SSSR. In 20 volumes. Leningrad: Gidrometeoizdat, 1973. Vol. 8. Part 06-07. 95 p.

7. Kerimov A.M., Kurasheva O.A. Degradation of glaciation in the Central Caucasus since the end of the 19th century and characteristics of the chemical composition of glacier-fed river waters. Modern problems of hydrochemistry and monitoring of surface water quality, September 22–24. Rostov-on-Don, 2020. P. 59–64.

8. Kerimov A.M., Kurasheva O.A. The content of the main ions in the Cherek River from its source to the exit to the foothill zone (KBR)» Successes of modern natural sciences, 2021. No. 11. P. 70−74.

9. Kerimov A.M., Kurasheva O.A. Peculiarities of the formation of the chemical composition of the rivers of glacier feeding in the Central Caucasus during intensive degradation of glaciation // Abstracts of the XVII glaciological symposium "The role of the cryosphere in the past, present and future of the Earth". St. Petersburg, 2020. Р. 66.

10. Kerimov A.M., Kurasheva O.A. River waters of glacial nutrition as high-quality sources of fresh water (on the example of the rivers of the Kabardino-Balkarian Republic) // Systems for ensuring technosphere safety, materials of the V All-Russian Conference and School of Young Scientists (with international participation). Taganrog, 2020. Р. 129–131.

11. Method for measuring the mass concentration of aluminum, barium, beryllium, vanadium, iron, cadmium, cobalt, lithium, manganese, copper, molybdenum, arsenic, nickel, lead, selenium, silver, strontium, titanium, chromium, zinc, in samples of natural and wastewater by atomic absorption method with electrothermal atomization using atomic absorption spectrometer modifications MGA-915, MGA-915M, MGA-915MD. NNDF 14.1:2.253–09 (M 01–46–2016). Moscow, 2016. 36 p.

12. Moor J., Ramamurthy S. Heavy metals in natural waters: Control and assessment of impact / Per. from English. M.: Mir, 1987. 288 p.

13. Ministry of Agriculture of the Russian Federation. Order dated 13.12. 2016. On approval of water quality standards for water bodies of fishery significance, including standards for maximum permissible concentrations of harmful substances in the waters of water bodies of fishery significance (as amended as of March 10, 2020). No. 552. 91 p.

14. List of water quality standards for fishery water bodies, including standards for maximum permissible concentrations of harmful substances in the waters of fishery water bodies Order of the Ministry of Agriculture of the Russian Federation of December 13. 2016. No. 552.

15. Russian Register of Potentially Hazardous Chemical and Biological Substances of the Ministry of Health of the Russian Federation. Maximum Permissible Concentrations (MPC) of Chemical Substances in the Water of Water Objects for Domestic Drinking and Cultural Water Use: Hygienic Standards. GN 2.1.5.1315-03. Moscow, 2003. 152 p.

16. Panov, V.D. Regime and evolution of modern glaciation of the basin of the river. Cherek Bezengi. L.: Gidrometeoizdat, 1978. 135 p.

17. Panov, V.D. Evolution of modern glaciation of the Caucasus. St. Petersburg: Gidrometeoizdat, 1993. 431 p.

18. Usubaliev, R.A. (2006) Changes in the content of chemical elements in the "snow-firn-melt glacial water" system // MGI, No. 101. P. 173-175.

19. Chapman D.V., Meybeck M., Peters N.E. Water Quality Monitoring // Encyclopedia of Hydrological Sciences. April, 2006. Р. 2–17.

20. Lepom P., Hanke G. (2008), Chemical Monitoring of Surface Waters // The Water Framwork Directive: Ecological and Chemical Status Monitoring. October, 2008.