International Proceedings of Chemical, Biological and Environmental Engineering, V0l. 101 (2017) DOI: 10.7763/IPCBEE. 2017. V101. 16

The Chemical and Isotope Methods Application for Risk Assessment Contamination of the Main Tributaries of the Transboundary Amudarya River

Inom Normatov1, Abulqosim Muminov1, Parviz Normatov2, Robiya Normatova1  1 Institute of Water problems, Hydropower and Ecology of the AS Republic of 2Tajik National University

Abstract. The results of chemical and isotopic analyses of the Transboundary River waters, the River and its tributaries are presented. As an indicator of impact of the mining enterprise wastewater in the basin of the Zeravshan River on the quality of water, a differential method of changing the chemical composition of water before and after the tailings dams’ wastewater was applied. The lack of heavy metals excess levels (Zn, Cd, and Hg, As, Pb) above the maximum permissible concentration of the corresponding elements in the Zeravshan River are observed. Detected change (heavier) of the Zeravshan River and its tributaries isotopic composition (δ2Н, δ18O) from upstream to the downstream of the river is associated with the evaporation process. The individuality ensuring of the Vakhsh River each tributary can be achieved by the sampling in points until the confluence of the respective tributary with the main river or another tributary. The exchanges of groundwater and surface waters in river basin were observed. The groundwater reservoirs of the Muksu River Basin (a tributary of the Vakhsh River) in dry periods nourishes the river Muksu. It is established that the chemical composition of the Zeravshan and Vakhsh Rivers is formed in the leaching process of rocks Keywords: transboundary, zeravshan, vakhsh, pollutant, isotope, tributary, amudarya

1. Introduction The first step is to clarify the importance of the problem the Transboundary Rivers and their tributaries quality. In the West in the 28-30 km below the city of Penjikent, Republic of Tajikistan, the Zeravshan River crosses the border and flows through the territory of the Republic of . The Zeravshan River total length is 877 km 303 km of which lie on the territory of the Republic of Tajikistan. The water quality problem in Transboundary river basins, in particular in the Zeravshan river basin, is compounded by the fact that up to now there is no network information sharing regarding the quality of the waterways between the neighboring States of . Herewith a uniform standard for assessing of the degree of anthropogenic load on geoenvironmental systems (maximum permissible concentration) is not developed. The water quality problem of the Zeravshan River is mostly associated with river pollution by wastewater of the Anzob mountain-concentrating combine - the mining enterprise for extraction and enrichment of mercury-antimony ores of the Dzidzikurut deposit. [1]-[10]. The Vakhsh River is the main river of the Republic of Tajikistan that merges with the Pyanj River and forms the – the largest river in Central Asia. Potential energy resources of the Vakhsh number 28.6 Million kWt·h (250 Million kWt·h/year of electricity). The development of the Vakhsh River hydropower potential is connected with the construction along with the now operating a number of large and medium hydropower station (HPS) with reservoirs [11]-[16].

 Corresponding author. Tel.: +992934450757 E-mail address: [email protected]. 113 Now one of the HPS reservoirs actual problems is the problem of sedimentation and the chemical composition of water caused by the problems of reducing the useful volume, corrosion of metal structures, as well as the degree of vital activity of living organisms in the reservoirs. The aim of this work is to study the chemical and isotopic composition of the rivers Zeravshan and Vakhsh and its tributaries, the establishment of stationary sources of pollution in rivers basin. 2. Object and Methodology The objects of studies were the Transboundary Zeravshan River, Vakhsh River and its main tributaries. The scheme (Fig. 1) that is formulated in [1] was used for the water sampling from the Zeravshan River and its tributaries. The complex chemical analyses of waters were carried out by the methods described in [8].

Fig. 1: Scheme of sampling of water from the Zeravshan River and its tributaries.

The water sampling for isotopic analysis was carried out according to the methodology developed at the University of Colorado in Boulder (USA). The water isotopic analysis were performed on Wavelength- Scanned Cavity Ringdown Spectroscopy (WS-CRDS). The individuality of each river, from the point of view of water chemical composition, is compiled by the tributaries sampling until the confluence with the main river and with other tributaries. 3. Result and Discussion 3.1 Hydrochemistry of the Zeravshan River and tributaries The chemical analyses results of the Zeravshan River are presented on the Fig. 2 that shows the difference of the chemical content values of cations and anions of the Zeravshan River water up to and after of the Anzob mountain-concentrating combine (AMCC) wastewater dams insignificant and do not exceed their MPC. It is obvious that the Zeravshan River is not polluted by wastewater of the AMCC.

Fig. 2: Results of chemical analyses of the Zeravshan River waters up to () and after ( ) wastewater dams of Anzob mountain concentrating combine. 114 The level of agriculture on upstream of the Zeravshan River that is determined by the orographic feature due to the limitation of irrigated land is underdeveloped. Therefore, it can be expected that the flow of the collector-drainage water runoff with high salinity to the river is negligible. The analysis of the histogram data (Fig. 2) on the composition of the waters shows that the Zeravshan River and its tributaries in the upper reaches do not experience anthropogenic pressure, and their mineralization is mainly due to the flushing water coastal mineral deposits. Oxygen isotopic and deuterium composition, deuterium excess are considered to be one of the informative indicators of hydrological and glaciological studies in the establishment of the regularities processes of ice formation, snow accumulation and the aggregate mutual transformations. The paper presents the water samples isotopic analyses results from the tributaries of the Zeravshan River: Sabag, Yarm, Samjon, Tro, Dehavz, Dihadang, Gusn and Dashtioburdon. The sampling for isotopic analyses was carried out according to the methodology developed at the University of Colorado in Boulder. The analysis were performed on Wavelength-Scanned Cavity Ringdown Spectroscopy (WS-CRDS) and the isotopic composition of hydrogen and oxygen expressed in relative terms δ2Н and δ18O:

δ = [(Rsample / Rstandard) – 1]∙1000‰ 2 1 18 16 Where Rsample and Rstandard relations H/ H and O/ О in the measured sample and the standard. As standard was adopted the average ocean water (SMOW, Vienna, IAEA). Measurement precision was ±0.05‰. At the isotopic analyses it was found that the upstream tributaries of the Zeravshan River are characterized by the light isotopic oxygen and hydrogen isotopes compositions: δ18O ( -13,23 : -13,43) ‰, δ2Н (-88,92 : -88,32) ‰ and deuterium excess 16.92-19.21 (Fig. 3). This suggests that the observed fractionation is a result of the freezing and the accumulation occurs in winter. In turn, the downstream tributaries of the Zeravshan River have the following isotopic composition: δ18O (-11. 98: -11.61) ‰ and δ2Н (-78.45: -75.80) ‰. The obtained results indicate about the existence of seasonal variations in the isotopic composition of precipitation and their influence on the isotopic composition of the river. In other words, its influence on the rainwater and meltwater ratio change from seasonal snow and underground waters.

Fig. 3: Results of isotope analyses of the Zeravshan River tributaries.

The location of the Zeravshan River tributaries is shown on the Fig. 4. The comparison of the isotopic analyses results (Fig. 3) with the scheme of location of the Zeravshan tributaries shows that as you move

115 from the upstream to the downstream there is the weighting of the water isotopic composition of the Zeravshan River relevant tributaries. The main factor of this process is the temperature increasing and therefore the evaporation of water from the rivers.

Fig. 4: Scheme of the Zeravshan River tributaries location.

3.2. Hydrochemistry of the Vakhsh River and tributaries Water quality monitoring of Transboundary Rivers, identifying the sources of anthropogenic pressures and the adoption of adequate measures for their elimination through the development of modern techniques is a valid tool to regulate the relationship between the components of geoecosystem. It is an important element of geoecological analysis of the Central Asia problems as a key link in the development of the rational use and protection of water ecosystems bases. The sampling of waters at the points shown on the scheme (Fig. 5) was carried out to study the chemical composition of the Vakhsh River waters and its tributaries.

Fig. 5: Scheme of sampling of water from the Vakhsh River and its tributaries.

The scheme of water sampling shows the respected individuality of each tributary from the point of view of chemical composition by sampling of tributaries water up to the confluence with the main stream of the river and up to the junction with another tributary. We carried out chemical analysis of rivers water and groundwater of the rivers basin the results of which are present on the Fig. 6 (a, b) and Fig. 7 respectively.

116 a b

Fig. 6: The results of chemical analysis of the waters of the tributaries of the Vakhsh River (a) and groundwater from river basins (b).

Fig. 7: The results of chemical analysis of the Vakhsh River.

The Fig. 6 & Fig. 7 shows that content of the chemical elements do not exceed established for their maximum permissible concentration. Consequently, formation of chemical composition of the Vakhsh river waters is mainly due to leaching of mineral rocks. The results of isotopic analysis of the Vakhsh River and their tributaries are presented on the Fig. 8.

-70

7

-90 5 6 4 3

-110

H,‰

2 δ

-130 1 2 y = 10,99x + 59,853 R² = 0,9957 -150 -18,5 -17,5 -16,5 -15,5 -14,5 -13,5 18 δ O,‰ Fig. 8: the Isotopic composition of water in the Vakhsh River and tributaries: 1, 2- Garmo glacier; 3 - Surkhob river; 4 – Vakhsh River; 5 –Obikhingou River; 6 – Kyzilsu River; 7 – River Muksu.

117 For interpreting the results of the Vakhsh River and its tributaries isotopic analysis, we will analyze the state of glaciation in the river basins. In the Surkhob River basin, there are intensively melting small glaciers of the Northern slopes in the Western part of the Peter the Great ridge. On the southern slopes of the Alay Ridge, glaciation decreases slower as there are larger glaciers. In the Obikhingou River basin, the largest glacier Garmo is intensively melting. During the XX century, it became shorter by almost 7 km, having lost more than 6.0 km2 in area. It is currently retreating at an average speed of 9 m/year, and the surface settles due to the melting of up to 4 m/year. Another glacier in the same basin, Skogach, retreats annually at 11 m. In view of this, it can be approved that glaciers feed the Surkhob and Obikhingou rivers and it can be assumed that precipitation mostly occurs in winter and isotopic composition is significantly lighter. The weather and climatic conditions of the Vakhsh valley are warmer than in the valleys of its tributaries Surkhob and Obikhingou and, consequently, due to evaporation process would have a heavy isotopic composition. However, the contribution of the water tributaries leads to the fact that the isotopic composition of the Vakhsh river water become lighter. The isotopic composition of the Kyzilsu river is characterized by values δ18O = -13.36 ‰, δ2H = - 87.88 ‰ which is close to the values of the water areas isotopic composition with an average annual temperature above 0 °C (Fig. 8). It was found that the isotopic composition of the river depending on the season changes in the following range: spring (δ18O = -13.4 ‰; δ2H = -96 ‰) and autumn (δ18O = - 12.4 ‰; δ2H= -89 ‰) [17]. It was assumed absents no significant contribution of glacial water to the Naryn River. Given this assumption, it can be concluded that runoff of the Kyzilsu River occurs due to seasonal rains. Previously [18] by analyses of chemical composition of river water and groundwater in the river basins of Tajikistan was suggested about the processes of underground water reservoirs enrichment by chemical elements of river water. Such mechanism but in the opposite direction, i.e. the conversion of underground waters reservoirs to the source of water for the river, for example, for the Muksu river basin was observed. -70 6 5 7 8 -80

о 4

-90 3

Н, % Н,

2 δ

-100 2 1 y = Основнойx + Основной R² = Основной -110 -15 -14 -13 -12 -11 δ18О, %о

Fig. 9: Isotopic analysis of spring (1, 3, 4, 5) and underground waters (2, 6, 7, 8) the basin of the rivers Muksu, Kizilsu, Surkhob and Obikhingou accordingly.

The results of the isotope analyses of spring waters and groundwater basins of the rivers Muksu, Kizilsu, Surkhob, and Obikhingou are shown on the Fig. 9. From the Fig. 9 can see that groundwater and spring water of the Muksu river basin by the values of the isotopic composition significantly lighter than the average composition of river water and close to the values of melted glacier water. During spring snowmelt by the processes of infiltration, underground reservoirs accumulate melt water and at dry periods turn to sources of runoff formation of river. Of course, it will affect to the river water isotopic composition.

118 4. Conclusion Thus, based on the conducted research to determine trends in temperature and precipitation for the period 1960-2012 it is observed that the water objects in the Vakhsh river basin is vulnerable to climate change. The increased water volume of the rivers, based on the data of Agency of Hydrometeorology of the Republic of Tajikistan on the reduction of the area of glaciation in the basins of the Vakhsh River, is due to the melting of small glaciers. Using the cyclical change in the Vakhsh River water volume predicted its value by 2030. In the basins of the investigated rivers, there are no stationary sources of pollution and the formation of chemical composition of water is mainly due to the leaching of mineral rocks. 5. Acknowledgments The authors express their appreciation to the U.S. Agency for international development (USAID) & NSA for their support to make this study through the CHARIS and PEER projects 6. References [1] M. Groll, Ch. Opp, I. Normatov. Water quality, potential conflicts and solutions an upstream-downstream analysis of the transnational River (Tajikistan, Uzbekistan). J. Env. Earth Sci. 2015, V. 73, N 2: 743-764. [2] O. Olsson, M. Gassmann, K. Wegerich and M. Bauer. Identification of the effective water availability from stream flows in Zarafshan river basin. J. Hydrology. 2010, 390:190-197. [3] P. I. Normatov. Water Quality of the Zeravshan River and chemical analysis of seasonal snow on the glaciers of the Zeravshan river basin. Vestnik Tajik National University. 2015, V. 1, N1 (102):306-310. [4] I. Normatov, Ch. Opp, P. Normatov. Monitoring and Analyses of impact of the industrial complexes on water quality of the Central Asian Transboundary Rivers. Proc. 6th International Conference Water Resources and Environment Research. Water & Environmental Dynamics. Koblenz: 3-7 June 2013, pp. 212-229. [5] P. Normatov. Social and ecological aspects of the water resources management of the Transboundary Rivers of the Central Asia. Red Book. IAHS Publ. 364, 2014: 441-445. [6] P. Normatov. Quantitative estimation of Hyman intervention Rivers on quality of waters of the Transboundary Rivers of the Central Asia. Abstracts. Goldschmidt, California: 8-13 June 2014, p. 1827. [7] P. Normatov. Monitoring Impact of industrial complexes on water quality and chemical analyses of seasonal snow of the Zarafshon River Basin glaciers. Proc.16th Annual Conference of the International Association for Mathematical Geosciences, New Delhi: 17-20 October 2014, pp.208-2012. [8] P. Normatov, R. Armstrong, I. Normatov. Variations in hydrological parameters of the Zeravshan River and its tributaries depending on meteorological conditions. Rus. Met & Hydrology. 2016, 41(9):657–661. [9] P. Normatov, R. Armstrong, I. Normatov, et al. Monitoring Extreme Water Factors and Studying the Anthropogenic Load of Industrial Objects on Water Quality in the Zeravshan River Basin. Russ. Met. &Hydrol.2015, 40(5):189-196. [10] P. Normatov, G. Frumin. Comparative analysis of hydrochemical parameters upstream and downstream of the Zeravshan Transboundary River. Proc. Rus. State Hydromet. Univ., 2015, 39: 181-188. [11] I. Normatov. The water balance and the solution of water problems in the Central Asian region. Proc. UNESCO/IAHS/IWHA Symposium. Rome: 1-4 December 2003, pp. 300-314. [12] I. Normatov. Country paper on regions of Tajikistan. G- WADI Asia-Global Network for Water and Development Information in Arid and Semi-Arid Regions of Asia. Intern. G - WADI Modeling Workshop. Roorkee: 2003, 36p. [13] I. Normatov. Regional experiences in solving water resources problems in Tajikistan. Building a New Asia. Ed: M. Singh. SHIPRA, 2005, pp.295-304. [14] I. Normatov, U. Murtazaev, N. Nasirov N. Creation of adaptation mechanisms: The key to more cost-effective and environment-friendly water management. IAHS Publ. 338, 2010, pp. 74-76. [15] I. Normatov, P. Normatov, A. Muminov. Modern adaptation approach of agriculture to the climate change and reservoirs impact. Proc. of 5th International Disaster and Risk Conf. Davos: 2014, pp.102- 106. [16] I. Normatov. Maintenance of Food Security in the conditions of change of Agroclimatic Resources and working 119 out of mechanisms of adaptation of agricultural crops to climate changes. Proc. Intern. Conf. Hydrological and Ecological Responses to Climatic Change and to LUCC in Central Asia. Urumqi: 2012, pp.170-176. [17] I. Tokarev, V. Polyakov, A. Samsonova et al. Water Isotope composition in the formation of conditions of the Toktogul reservoir water budget. hge.spbu.ru/download/tokarpapper/isotopes.pdf [18] M. Kholmirzoeva, A. Radzhabova, S. Buranova, I. Normatov. Monitoring and physical-chemical studies of ground and surface water sources of Republic of Tajikistan. Water: chemistry and ecology. 2012, 6: 92-96.

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