Svetlana V. Borzenko

Hydrogen Sulfide and Other Reduced Forms of Sulfur in Oxic Waters of Lake Doroninskoe, Eastern Transbaikalia

Simultaneous occurrence of oxygen and hydrogen sulfide was established by hydrochemical investigations in the waters of the Black and Baltic seas at a depth of more than 50 m (c-layer) [1‐3, 9, and others]. The most probable reason for the appearance of H 2 S and other sulfur species with intermediate oxidation states (thiosulfates and sulfites) is sulfate reduction in situ, i.e., immediately in the c-layer. A great number of publications have been devoted to the problem of the formation of hydrosulfuric, especially underground, mineral waters [6, 11, and others]. However, the presence of H 2 S in the oxic layer was reported only by few authors [8 and others], who believed that hydrogen sulfide can be supplied in part from bottom sediments. Data on other sulfur species (mainly, thiosulfates and sulfites) are rare [4]. The formation of suboxidized sulfur species (thiosulfates and sulfites) in waters during the oxidation of sulfide deposits has been studied in more detail [7]. The distribution of sulfur species in soda waters of Lake Doroninskoe has been studied since 2003. This work has been supplemented by determinations of oxygen since December 2005. The lake (4.5 km 2 in area and up to 6.5 m deep) is located at the bottom of the Mesozoic Chita‐Ingoda intermountain depression in the Ingoda River basin, one of the sources of the Amur River. The lake is underlain by Early Cretaceous sandy‐silty deposits intercalated with intermediate‐ basic effusive rocks. The bottom muddy sediments (up to 10 m thick) contain up to 0.4% iron sulfides [5]. The basin lacks drainage, and its water is characterized by high salinity due to evaporation. Water was sampled from top to bottom using a plexiglas bathometer or peristaltic pump at two stations located in the central and coastal parts of the lake. Dis

Elemental Sulfur in the Brine of Lake Doroninskoe (Eastern Transbaikalia)

The concentration of elemental sulfur (S0) in the upper oxic layer of the meromictic (stratified by water mineralization) soda Lake Doroninskoe (about 5.5 m depth) varied in the survey periods from the detection limit (0.002 mg/l) to the registered maximum of 0.444 mg/l, with an average value of 0.12 mg/l. In the lower hydrosulfide layer, these concentrations amounted to 0.012–1.88 mg/l. The results obtained point to the processes of sulfide sulfur oxidation under reductive conditions, and of sulfate reduction to form hydrogen sulfide in the oxic medium. The dynamics of the seasonal S0-thiosulfate ratio testifies to the dual (oxidative and reductive) nature of the latter.

Geochemical features of Kulunda plain lakes (Altay region, Russia)

Geochemical specifics of lake water of the Kulunda Steppe territory (Altay region, Russia) are studied. The results show that in the territory mainly chloride and less soda lakes with sodium compound are developed. It is presented that calcite and soda saturation indexes (SI) of lake water increase with growth of pH, but decrease in such minerals as gypsum and barite. The opposite situation is typical for SI depending on the salinity. It is revealed that evaporation, secondary mineral formation and various biological processes have the greatest impact on accumulation of elements in solution.

Uranium in the mineralized lakes of Altai Krai

Data on the physicochemical properties (pH, Eh, salinity) and content of U and other trace elements (As, Li, B, Br, I, Sr) are provided for the mineralized lakes of the Kulundinskaya steppe of Altai Krai. The sodic lakes of the region are characterized by higher U238 contents (up to 4 mg/l). The U contents in the lake waters are positively correlated with the sum of carbonate and hydrocarbonate ions and the pH of waters and are negatively correlated with salinity. These data confirm the presence of an economic U-bearing zone of the ground reservoir oxidation located along the eastern slope of the Platovskoe uplift in the northwestern direction along the boundary with Kazakhstan.

Thermodynamic Evaluation of Mineral Balance in Water Thickness of the Soda Lake Doroninskoe (Eastern Transbaikalia, Russia)

In recent years,lakes,including salted,attract the attention of researchers,also when reconstructing last climate changes using the bottom sediments(Solotchina et al.,2008,et al.).In this case the different geochemical

Chemical composition and sulfur forms in saline lakes of Kulunda Plain (Russia)

1 Introduction On the territory Kulunda Plain,located to the south-west of the Ob’plateau,there are more than 3,000 fresh and salt lakes with water TDS range from 1 to 430 g/L.The interest in these lakes was associated mainly with the study of

Isotopic Composition of Dissolved Carbonates Meromictic Soda Lake Doroninskoe (Eastern Transbaikalia, Russia)

1 Introduction Meromictic soda Lake Doroninskoe localized in the intermountain area,filled with continental sediments of the Mesozoic,in the upper basin of the river Amur.Coordinates of its location are N51°14’42E112°14’40,

Biogeochemical conversion of sulfur species in saline lakes of Steppe Altai

The aim of the present research is to identify the main mechanisms of sulfur behavior in saline lakes in the course of time and followed transformations in their chemical composition. The influence of water on chemical composition of biochemical processes involved in decomposition of organic matter was determined by the study of behavior of reduced forms of sulfur in lakes. The determination of reduced forms of sulfur was carried out by successive transfer of each form of sulfur to hydrogen sulfide followed by photometric measurements. The other chemical components were determined by standard methods (atomic absorption, potentiometric method, titration method and others). The salt lakes of the Altai steppe were studied in summer season 2013–2015. Analysis of the chemical composition of the saline lakes of Altai Krai has shown that carbonate-, hydrocarbonate- and chloride ions dominate among anions; sodium is main cation; sulfates are found in subordinate amounts. Reduced forms of sulfur occur everywhere: hydrogen and hydrosulfide sulfur S2- prevail in the bottom sediments; its derivative—elemental S0 —prevails in the lakes water. The second important species in water of soda lakes is hydrosulfide sulfur S2-, and in chloride lakes is thiosulfate sulfur S2 O32-. The lag in the accumulation of sulfates in soda lakes in comparison to chloride lakes can be explained by their bacterial reduction, followed by the formation and deposition of iron sulfides in sediments. In chloride lakes gypsum is a predominantly barrier for sulfates.

Basic formation mechanisms of Lake Doroninskoye soda water, East Siberia, Russia

Abstract The primary scientific goal of studying salt lakes is to better understand the formation of small continental-type hydrogeochemical systems. Many scientists have attributed the metamorphism of the chemical composition of salt lakes to the evaporative concentration of water. However, the formation of soda water is inconsistent with this hypothesis. Thus, analyzing intrabasinal biochemical processes and water—rocks interactions during the evaporative concentration of water allows us to understand the major mechanisms of the formation and evolution of water compositions. Therefore, the aim of this paper is to identify the key processes involved in the formation of the chemical composition of the water in Lake Doroninskoye. An analysis of the distribution of major components shows that Na+, HCO3−, CO32−, and Cl− are dominant in this water. High concentrations of these elements are the result of evaporative water concentration. Calcium, magnesium, and potassium are not accumulated because the water is saturated in minerals containing these elements. The main barrier to the growth of the sulfate content of water is sulfate reduction. This process also contributes to the additional reproduction of carbon dioxide, which reacts with the products of the hydrolysis of aluminosilicates OH− to form HCO3− and CO32−, thus further contributing to the natural processes of soda formation.