Українська   Русский

Abstract

Introduction

The Donetsk region is particularly intense environmental of environmental-economic area because of the unique combination of the powerful industry, extremely dense transportation network, intensive agriculture and associated very high anthropogenic load, complex natural complex. The high level of exploitation of resources, recycling of fuel significantly affects the environment. Special attention is environmental pollution by heavy metals. The most active pollutants include mercury – an element of the first class of danger. The environmental and Toxicological effects strongly depends on in what chemical form it is present. Distribution of forms of mercury and the processes of its transformation in natural water systems are controlled by various physical, chemical and biological factors. Depending on the natural conditions of inorganic forms of mercury can be transformed many times more toxic than compounds [1].

1 The relevance of the topic

Coal deposits contain a wide range of related heavy metals, prisoners, both in the coal and in the host rocks and mine waters. It should be noted that the coal rocks is especially saturated with mercury, this is primarily due to the fact that on the territory of Donetsk region Gorlovka) is Nikitivski mercury plant (now defunct). It was found that in Gorlovka, especially near the content of Nikitovka mercury vapor virrueta in the range of from 155–up to 300 1427–1680 mg/l   this is a causal mercury intoxication of the region's inhabitants on the local level and all the inhabitants of the Donetsk region as a result of cross-border transfers at the regional. Studies on the sampling of coal seams of the Donets basin with the aim of assessing the degree of enrichment of metals of coal and the potential impact them on the environment was carried out: Dvornikova in the 80-ies, and in 2004 the specialists of the departments of Minerals and Environmental Geology (Panov B. S., Korchagin V. A., Panov J. B.) in collaboration with American scientists (Kolker A. G., Landa E. R.).

In the underground workings of the water supplied by seepage of groundwater and surface water sources, contamination of various kinds. The danger is that, in the discharge of insufficiently treated mine water in natural objects, due to the overload and untimely purification septic tanks, increased the likelihood of ingress of mercury compounds, which are in turn the result of natural processes are transformed into toxic complexes. Thus there is the pollution of surface waters of the city, as well as in the area of risk are all components of the biosphere.

The process of mercury contamination that comes with mine waters in natural sources of environment, presented in figure 1 [2].

2 The purpose and objectives of the study, expected outcomes

The purpose is to reduce concentrations of mercury in natural and mine waters to the maximum permissible levels.

The goal of the study involves the following tasks:

  1. To review the literature on mercury in the aquatic environment.
  2. Analysis of the sources of water pollution.
  3. To Explore the content of mercury in natural and mine waters.
  4. To assess water quality.
  5. Review and analyse existing methods of water treatment from mercury compounds.
  6. Offer your own ideas and developments to improve existing methods of purification.

The object of study: natural and mine waters of the Donetsk region.

The subject of the study: the processes of accumulation of natural and mine waters containing mercury and its compounds.

3 The practical significance of the results

The Implementation of experimental results, namely: the actual concentrations of mercury in natural and mine waters can be used environmental and sanitary-epidemiological services for the development of systems of measures to improve the ecological status of the water environment in the Donetsk region. Data can also serve as a source of information when writing a master thesis at the Department of Applied ecology and protection of environment.

3.1 Approbation of work

The results of the research were presented at the Interuniversity student conference towards The Use of modern management techniques in order to improve the efficiency of enterprises (Donetsk, 2015), I open the Republican scientific-practical conference of pupils and students, teachers of secondary schools and institutions of additional (extra-curricular) education (Donetsk, 2015), IX International scientific conference of graduate and undergraduate students in the direction of Environmental Protection and rational use of natural resources (Donetsk, 2015).

3.2 Publications

According to the materials of the master's work published 3 research papers, 3 abstracts of conference presentations

4 Content of mercury in water bodies on the territory of the Central Donbass

Mercury in very small amounts present in natural surface waters, the main storage in water systems are bottom sediments. The presence in the aqueous medium of one or another form of mercury is influenced by the acidity of the water environment and its oxidation potential [3].

In the waters of the mercury migrates in two major phase States   in a solution of water (dissolved form) and in suspension (suspended forms). In turn, in a solution of water it can be in the form of a divalent ion, hydroxide mercury, complex compounds (chlorine, organic matter, etc.). Among the compounds of Hg (II), by their environmental and Toxicological importance of the special role of organomercury compounds. High concentrations of mercury characterized technogenic silts, actively accumulating in the rivers and reservoirs, where it receives the wastewater industry. The mercury levels in them are up to 100–300 mg/kg and more (in the background to 0.1 mg/kg). Known cases when the amount of mercury received with wastewater and accumulated in such Ilah was dozens and hundreds of tons. The normal functioning of these rivers and reservoirs, their practical use is possible only when you remove the contaminated sediments [4].

Typical background levels of total mercury (dissolved form) in natural fresh waters is 0.03–0,07 mg/l, in bottom sediments of rivers and freshwater lakes   at 0.05–0.1 mg/kg in freshwater plants   0,04-0,06 mg/kg dry weight. Usually there where no indications of contamination by mercury, its levels in drinking waters seldom exceed 0.1 mg/l [5].

The Presence of mercury in surface water bodies of the city of Donetsk is generated largely anthropogenic intake of this element. Chemical composition of river water is directly dependent not only on the chemical composition of surface runoff and groundwater, but also on the chemical composition and quantity of water discharged. A significant contribution of wastewater coal mines (mine water). The penetration of water into mine workings occurs from the surface to aquifers through fractures in rocks, and previously passed the underground workings. It is known that mercury in the process of tectonic activity migrated and accumulated not only in mercury deposits, but also in the layers of rocks. Therefore, it is recorded that mercury has a high excess compared to the Clarke content in the coal mines of the Central Donbass. Over the years the excess is increased, this is primarily due to the fact that on the territory of Donetsk region (city Gorlovka) is Nikitivski mercury plant (now defunct). It was found that in Gorlovka, especially near the content of Nikitovka mercury vapor varies from 155–up to 300 1427–1680 mg/l [6].

The analysis of the distribution of surface water pollution with mercury shows that the main role in environmental pollution by this metal play coal (mines), coal processing and preparable enterprises, and household burning of coal. The average mercury content in the burnt dumps of coal mines and processing plants is 0,185 mg/kg. In burning same dumps it ten times more (1,85 mg/kg). Around the heaps of coal mines the amount of mercury is much more background. The sludge by-product coke plants the amount of mercury 1,12-1,18 mg/kg, and in the ash and slag of thermal power plants on Donetsk coal mercury content is from 0.17 to 1.55 mg/kg. it Should be noted that for January 2012 in Donetsk oblast worked 95 coal mines. As of January 2015, the situation has changed considerably, with many mines temporarily ceased to function – this is primarily due to the political situation in the Donbas, but also there are other reasons. This situation entails the natural flooding of mines groundwater, since the pumping of mine waters is not made and as a result   large-scale contamination with mercury compounds and other contaminants in all environmental media. Anomalous concentrations of mercury in surface water bodies established in other areas of Donbass, for example, in Gorlovka over 100 years extracted and processed mercury ore nikitovski field and there are several large coking plants [7].

To the dangerous districts of Donetsk region on the General background concentrations of mercury can be attributed to the city of Makeevka, Dzerzhinsk, Donetsk region, Avdeevka, Mariupol, Konstantinovka and others. These areas require special attention in the field of quality control environment [7].

5 The study of mercury compounds in different water bodies of the Donetsk region

For proper analytical assessment of water pollution of decisive importance is the correct water sampling. Single samples were collected   this is a single sample, which are selected manually or automatically with the water surface at certain depths or from the bottom. Each sample characterizes the quality of water only now and in this place. For sampling water use dishes made of borosilicate glass, quartz, polysulfone or fluorinated polyethylene-propylene. Glassware is cleaned in the usual way (water and soap), rinse with 10 % nitric acid and then with distilled water to remove traces of heavy metals. Determination of mercury in aqueous solutions is carried out using flameless atomic absorption method of analysis, based on measurement of absorption of radiation with a wavelength of 253.7 nm atoms of mercury, which are excreted in the analyzed samples after recovery of mercury to the elemental state. Based on the work of the mercury analyzer Julia–2 it is the absorption of radiation by mercury atoms in the ultraviolet region of the spectrum. For preparation of samples used generally accepted methodology, which is presented in the main part of the work. The range of measurement of Hg concentrations from 0.0015 to 0.015 g/cm3. The relative error of the analyzer does not exceed 20 %.

To study the presence of mercury in mine waters of the Donetsk-Makeevka coal-mining basin were selected mines located in various parts of the city and having different hydrogeological conditions. Also samples were taken from natural surface water sources. The analysis showed that in 70 % cases its concentration exceeds the maximum allowable levels.

6 Testing of existing methods of waste water purification from mercury compounds

For separation of mercury from waste water using reagent (reductants: iron sulfide, sodium sulfide, hydrazine, iron powder, gaseous hydrogen sulfide and others), sorption and ion-exchange methods for cleaning. Chemical method of removing water soluble mercury compounds is their conversion into difficultly soluble sulfide of mercury and its deposition. To do this, in the waste water is first added sodium sulfide, sodium hydrosulfide or hydrogen sulfide. Then treat the water with chlorides of sodium, potassium, magnesium, calcium, or magnesium sulfite in the amount of 0.1 g/l. under these conditions, the mercury sulfide is precipitated in the form of granules. For removal of fine colloidal particles of sulphide of mercury, it is advisable to add coagulants. The precipitate mercury sulfide is separated from the wastewater in the vacuum filters, or filter presses. Department НgS to a residual concentration of 0.001 mg/l can be achieved on carbon filters. The spent carbon containing mercury sulfide, is burned in a furnace or treated for the recovery of mercury. Sorption methods   processes of formation of the amalgam of mercury in the electric field. The method is suitable for treatment of wastewater containing from 0.01 to 100 mg/l mercury compounds. In this process the waste water is filtered through layers of glass spheres, coated with copper or zinc. Balls are the cathode, and the outer casing   anode. When regeneration of the filter load produces a polarity reversal of the electrodes. When ion-exchange methods happen exchange reactions: dissolved mercury is fully transferred from solution to the surface of the cation exchange resin and removed from the ion-exchange filters water contains almost no ions [9].

These methods of water purification from mercury compounds purify it to certain values, but they do not reach the maximum permissible norms. Conducting numerous tests and testing in a laboratory all available methods of purification showed that the most efficiently in terms of the Donetsk region decreasing concentrations of mercury compounds it is possible to achieve the method of translating them into difficultly soluble substances, followed by their deposition and removal from the treated water [10].

When writing this abstract master's work is not yet complete. Final completion: December 2015. The full text of the work and materials on the topic can be obtained from the author or his supervisor after that date.

Source List

  1. Рамамурти, С. Е. Тяжелые металлы в природных водах / С. Е. Рамамурти. – М.: Мир, 1987. – 286 с.
  2. Гороновский, И. Т. Краткий справочник по химии / И. Т. Гороновский,Ю. П. Назаренко, Е. Ф. Некряч. – К.: Издательство АН СССР, 1962. – 658 с.
  3. Крайнов С. Р. Геохимические и экологические последствия изменения химического состава подземных вод под влиянием загрязняющих веществ / С. Р. Крайнов, Г. Ю. Фойгт, В. П. Закутин // Геохимия, 1991, № 2. C. 169–182.
  4. Панов Б. С. К геоэкологии Донецкого каменноугольного бассейна / Б. С. Панов, О. А. Шевченко, А. М. Дудик, С. Ю. Селяков // Известия ВУЗов, серия геология и разведка, 1998, № 5. C. 138–145.
  5. Петросян В. С. Загрязнение ртутью: причины и последствия / В. С. Петросян // Экология и промышленность, 1999, № 12. C. 34–38.
  6. Петросян В. С. Ртуть и ее соединения в окружающей среде / В. С. Петросян // Человек и среда его обитания. М.: Мир, 2003. C 282–290.
  7. Масляев В. С. Разработка методов аналитического контроля на содержание ионов тяжелых металлов в различных видах шахтных вод в Донецко-Макеевском угледобывающем районе / В. С. Масляев, Г. В. Чудаева, И. Л. Жислина, К. Ф. Гусарова. – Отчет. Донецк, 1992. – 65 с.
  8. Збощик М. П. Исследование углистопородистых осадков прудов-отстойников шахт и шламонакопителей обогатительных фабрик на осаждение в них тяжелых металлов / М. П. Збощик, Г. В. Чудаева, И. Л. Жислина, К. Ф. Гусаров. – Отчет о НИР. Донецк, 2002. – 91 с.
  9. Смирнов, Д. Н. Очистка сточных вод в процессах обработки металлов / Д. Н. Смирнов, В. Е. Генкин. – М.: Металлургия, 1980 – 195 с.
  10. Державні санітарні правила і норми Вода питна. Гігієнічні вимоги до якості централізованого водогосподарсько-питного водопостачання [Електронний ресурс]. – Режим доступу: http://ukraine.uapravo.net.