Heavy metals and natural radionuclides in the water of Syr Darya River, Kazakhstan

Abstract

Abstract. This study deals with concentrations of heavy metals and the main uranium series radionuclide in the Syr Darya surface waters (Kazakhstan). Large proportion of studied heavy metals were transported with suspended matter (>0.45 μm), while large proportion of U (98-100 %) and Mo (81-100%) were in dissolved forms and colloidal fraction (<0.45 μm).

Distribution Characteristics and Assessment of Heavy Metals in the Surface Water of the Syr Darya River, Kazakhstan

“…The state of heavy metal pollution in river waters from abroad and within the country has been severe for a long time, and with the fishery being one of the pillars of economic development in the research region, fishery water environment quality has a potential impact on regional economic development. The results of the detection of heavy metal content in surface water of this study are higher than those of previous research results [16,17,[37][38][39][40][41], which indicate that the heavy metal pollution of surface water in the region is developing in a more severe direction (Table 2). From a biological perspective, the presence of heavy metals may pose a threat to fish and other aquatic organisms that inhabit the Syr Darya River, and furthermore it can also threaten human health through bio-enrichment, so it is necessary to focus on strengthening the supervision and treatment of regional heavy metal pollution.…”

“…Part of Kazakhstan is the most ecologically and environmentally sensitive area in the whole basin; it is also the main life-supporting freshwater artery of southern Kazakhstan [15]. Anthropogenic activities such as mining and tailing accumulation, the ultimate disposal of treated and untreated waste effluents containing toxic metals as metal chelates from different industries, and contamination from intensive agricultural activities that use mineral fertilizers have become potential sources of heavy-metal contamination in the surface water of the Syr Darya River [15][16][17]. Therefore, it is especially important to understand the state of heavy metals in the aquatic environment of the study area.…”

Potential eolian dust contribution to accumulation of selected heavy metals and rare earth elements in the aboveground biomass of Tamarix spp. from saline soils in Kazakhstan

“…Content and composition of salts and metals/metalloids and REEs in soils of arid regions depends on weathering and pedogenic processes that result from the geological and geomorphological characteristic of a given area and are under influence of hydrological and climatic factors. Currently, a major role is played as well by human influences, namely industrial activities, and, especially in arid regions, irrigated agriculture (Kitamura et al 2006 ; Satybaldiyev et al 2015 ; Laiskhanov et al 2016 ; Hamidov et al 2016 ). Apart from these factors, many studies performed in arid zones highlighted the importance of eolian dust in shaping soil chemistry, even at a long distance from its original source (Issanova et al 2015 ; Zhang et al 2016 ; Opp et al 2017 ).…”

Distribution of dissolved and suspended forms of heavy metals in the water of the Syr Darya, South Kazakhstan

“…Географические координаты мест отбора проб определялись с помощью спутникового навигационного прибора Garmin GPS 12XL (таблица 1). Карты с точками отбора в низовье реки приведены в работе [8], в верховье реки -в работе [9]. В местах отбора проб определяли pH, содержания кислорода, электропроводность с помощью полевой лаборатории типа HACH (Hach Corporation, Loveland, США).…”