Transformation of the Spring High-water and Flood Runoff in the Upper Volga Basin under the Climate Change Impact

An increase in the average annual air temperature in the European territory of Russia against the background of climate change leads to a decrease in water reserves in the flood-forming snow cover. At the same time, an increase in the number of transitions of air temperature through 0 ° С in the area of positive values in winter leads not only to an additional reduction in snow storage by the beginning, but also ensures an increase in the number and size of thaw floods. Changes in the intra-annual distribution of the range and intensity of precipitation entail an increase in the number and magnitude of rainfall floods. Observed transformations in the types of feeding and water regime of the rivers of the basin. Methods. The study posed the task of studying climate change on the hydrological regime of rivers in the Upper Volga basin. To solve it, methods were used to determine the methods for determining the runoff components based on the dismemberment of the hydrograph using the GrWat software package and mapping the results of the results. As part of this task, more than two thousand hydrographs were analyzed, and their long-term trends were analyzed. Results. The analysis showed that on some rivers of the region the volume of flood runoff is already comparable to the volume of flood runoff, which is not typical for the river-European type of water regime. It was found that for some rivers in the region, the volume of runoff during high water decreased by more than 50%, while the volume of runoff during the period of rainfall floods increased by more than 80%,while in the period of thaw practically by 100%.

Drinking Water Supply under the Conditions of Mass Development of Blue-green Algae in Reservoirs.

An assessment of the pollution of a surface source of water supply (the Kuibyshev reservoir) with metabolites of cyanobacteria (blue-green algae) under conditions of an increase in biogenic load is carried out. During the period of mass development of cyanobacteria, the quality of water in the reservoir deteriorates in terms of a number of indicators, including smell, taste, and content of organic and toxic substances. Among the wide range of cyanoxins, the greatest danger to the population is microcystin-LR, the concentration of which in drinking water should not exceed 1 μg/dm3. The growth of anthropogenic load and global warming of the climate create favorable conditions for the rapid development of cyanobacteria, therefore, the problem of providing the population with high-quality drinking water will only worsen in the future. Traditional methods used at drinking water treatment plants in Volga cities are ineffective in removing intracellular and extracellular cyanotoxins. The best and safest barrier against the ingress of cyanotoxins into drinking water can be membrane technologies that allow ultrafiltration of bacterial cells without mechanical damage and nanofiltration of cyanotoxins dissolved in water.

On the Issue of Assessing the Ecological State of Various Watercourses in the Conditions of Anthropogenic Pressure.

An assessment is given of the ecological state of nine rivers with different levels of anthropogenic load related to the Volga, the Don and the Ural basins. The water quality was assessed on the basis of several indices: the widely used specific combinatorial water pollution index (SCWPI), and statistical criteria based on the data of long-term environmental monitoring: the plasticity indicator as a measure of ecosystem sustainability and the desirability function. Hydro/chemical studies included indicators of oxygen regime, salt composition, organic matter, biogenic and toxic elements. The calculated SCWPI fluctuated in the range of 3,0–5,4, which corresponds to the quality category “very polluted” - “dirty”. The water of the lowest quality is in the small rivers Berezina and Elshanka, part of which is located in the industrial zone of the city of Saratov. The greatest contribution to the assessment of the degree of water pollution is made not only by the concentration of technogenic metals, but also by indicators of the content of organic matter, the amount of which depends on the level of bioproduction processes. The principal component analysis made it possible to structure the indices calculated for each river and to “explain” some of the information contained in the initial variables. Two main components were selected, based on the analysis results. The first factor integrates a negative relationship between the value of the UCIPI and the length of the river. Large rivers are more resistant to pollution due to their high water content. The second factor incorporated environmental criteria - the desirability function and the plasticity indicator, i.e. statistical indicators based on the data of long-term hydro/chemical monitoring and taking into account the real ecological state ̶ "health" of natural water systems and their sustainable functioning. Cluster analysis of the obtained statistical indices made it possible to divide the studied rivers by the quality of the aquatic environment into 4 groups.

Artificial Impacts upon Water Bodies

Some aspects of the history of waste water disposal systems regulation and setting of criteria of maximal permissible impact upon water bodies have been discussed. Approaches based on three various concepts, i.e. environmental, consumptive, and technological are the most wide spread both in this country and abroad. We have shown that the crisis of the currently active regulation system in this country is mostly connected with the lack of attention to the special features of the concrete water bodies natural hydro/chemical regime in the process of the double genesis substances disposal regulation.

Features of the Spring Flood Formation in the Arpa River Basin

The article considers main physical and geographical factors affecting the runoff, spring flood of rivers in the Arpa River basin, and analyzes the regularities of their spacetime distribution. The authors have obtained correlation relationship between the values of the flood runoff layer, the mean module maximum runoff and weighted average height of the catchment area of the Arpa River, between the mean annual maximum runoff module for the period floods and catchment areas of rivers. These dependencies can be used for preliminary estimates of the spring flood runoff of unexplored rivers of the territory under consideration. A close correlation between the values of the annual runoff and the runoff of the spring flood in the section of the Arpa River – Dzhermuk has been also revealed. It can be used for forecasting the annual flow.

Analysis of radon and radium content in springs of the city of Ekaterinburg and its outskirts

Despite development of central water supply systems, springs still remain to be important sources of drinking water. In this work, the study of water quality in springs of Yekaterinburg city and its settlements was performed with the attention to radiological factor. Activity concentrations of radium-226 were determined in water of 20 springs. Methods. Determination of the radon-222 activities of was performed using gamma-spectrometry vis the equilibrium bismuth-214 gamma line. To determine radium-226, 5-liter water samples were taken, the radium was preconcentrated on a T-5 sorbent; then radium was separated on a thinlayer MnO2-PE sorbent followed by measurement on an alpha spectrometer. Results. In the vast majority of cases, activity concentrations of radium-226 were lower than the detection limit (0.3 Bq/L); the maximal activity concentration of 1.03 ± 0.27 was found that corresponded to the internal dose of 0.21 ± 0.05 μSv/y due to daily consumption of this water. No correlations were found between content of radium-226 and concentrations of radon-222, uranium-238 and alkaline earth ions. At the period of 09.2020 – 06.2021, monitoring of radon activity was performed in seven springs with previously found high radon content. Significant seasonal variations of radon activity were found; for some springs the difference between the minimal and the maximal activity reached 3. In the most cases, increase of radon activity occurred in water during winter that can be explained by both an increase of radon solubility in cold water and a decrease of flowrate.

Sorption Extraction of Strontium Radionuclides from Surface Water by Natural Aluminum Silicate

The contamination of large volumes of surface waters with radionuclides is caused by the appearance of a significant number of objects that pose a potential radiation hazard. The search and development of affordable, environmentally friendly sorbents for the purification of such waters is an urgent task, the solution of which will make it possible to propose effective measures for the purification of natural water bodies from pollution. The article presents the result of research of sorption reduction of 90Sr radionuclide from aqueous solutions with experimental samples under static and dynamic conditions. Methods. We have defined the strontium concentration range within which the reduced component distribution between solid and liquid phases obeys Henry law. The granulated sorbent distribution index in the Henry area was Kd=(3.46±0.2)•102 ml/g in terms of strontium and this is comparable with the Kd=200 ml/g value of the initial natural glauconite. The obtained value of the sorbent static exchange capacity in terms of strontium in the (10-5 – 1) g/l concentration range is ≥ 4.2 mg/g. We investigated the sorption kinetics in the recirculation mode. We have presented the output curves of the strontium sorption with the developed sorbent in the dynamic mode. The strontium distribution index was at least 2.42 ∙ 103 ml/g and this approximately 10 times exceeded the value obtained under the static conditions. After passing of 900 column volumes of the model solution through the column, no compacting of the sorbent was observed and this confirmed preserving of its hydro/dynamic characteristics and the possibility to use it as a filter loads in ant water treatment systems. Results. The sorbent produced from local mineral raw material is applicable and feasible for use in treatment of the Ural region water bodies contaminated with 90Sr. We have demonstrated good perspective of the natural aluminum silicate glauconite of the Karinsk deposit (Chelyabinsk Oblast, Russia) granulated with bonding tap water use as a sorbent for extraction of strontium radionuclide from natural waters in the process of radioactive-contaminated territories.

Deironing of Underground Water with Modified Refractory Chamotte

Water from underground sources in Russia and the CIS countries mainly contains higher concentrations of iron and manganese. With a permissible rate of iron content in drinking water of 0.2–0.3 mg/L, its content in groundwater can reach 40 mg/L. To remove excess soluble iron, it is oxidized to insoluble forms. For these purposes, iron removal filters are used. This research describes the preparation of modified catalytic material to intensify the process of deferrization of underground water. Methods. Refractory chamotte of a fraction of 3–5 mm was selected as the base material, and an iron-containing precipitate of the purification of washings waters from iron removal filters was used as the source of iron for the preparation of the precursor solution. As a result of the modification, the formation of a finely dispersed and crystalline structure of hematite on the chamotte surface occurred. The effect of the dose of iron nitrate on the iron content on the surface of the modified material is established. Results. During pilot tests, it was found that an increase in the concentration of iron on the surface from 5.8 wt.% in the initial chamotte to 19.0, 48.7 and 55.8 wt.% in the modified led to an increase in the degree of iron oxidation from Fe2+ to Fe3+ from 41.4% to 65.1, 73.0 and 80.0%, respectively. The proposed method has significant advantages over analogues due to significantly lower energy consumption, resource consumption and impac on environmentt.

Application of European Approaches to Determination of Technological Indicators of the Best Available Techniques in the Field of Wastewater Treatment

The year 2014 was a turning point in the transition of the main sectors of the Russian economy to a new track of environmental regulation and the introduction of obligations for first category’ s objects of negative environmental impact to receive a unified complex document containing mandatory requirements in the field of environmental protection. The main element in the application for a comprehensive environmental permit is the results of calculations of technological standards based on technological indicators of the best available techniques.The determination of technological indicators of the best available techniques takes place in the process of developing and updating information and technical reference documents (BREFs) on the best available techniques. There is currently no unified methodology for determining the technological indicators of the best available techniques. In the process of determining them in Russia, an expert assessment, a reference to the opinion of the industry professional community, or a compromise between control and supervisory authorities, departmental executive authorities and enterprises prevails. Methods. The authors have obtained a set of data through questionnaires from wastewater treatment plants of various output and water treatment techniques used. We have a developed a unified questionnaire that enables to get general information on the plants under study, as well as detailed information on pollutants’ discharge and the use wastewater treatment techniques. Results. In this article, the technological indicators of the best available technologies in the field of wastewater treatment using centralized wastewater disposal systems of settlements or urban districts were determined based on the proposed European approaches. The results obtained showed that the resulting total range generally corresponds to the values of technological indicators of the best available techniques established by the Government of the Russian Federation for water treatment enterprises. Thus, it is possible to judge the applicability (taking into account the expert assessment) of this approach for determining the technological indicators of the best available techniques in other information and technical reference documents (BREFs).