Минералогия и геохимия на приповърхностните дънни отложения от язовир Огоста и вливащите се в него реки : Автореферат /
The dissertation is dedicated to the pollution with heavy metals and metalloids in a region of Northwestern Bulgaria that is historically connected with ore mining and processing. Ore mining industry is one of the main polluters of the environment the consequences of whose activities are complex and...
| Основен автор: | Иванова, Ирена Георгиева |
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| Други автори: | Младенова, Василка Георгиева 1956- (науч. ръководител), Ivanova, Irena Georgieva |
| Формат: | Книга |
| Език: | Bulgarian |
| Публикувано: |
София,
2013.
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| Предмети: | |
| Онлайн достъп: |
Пълен запис |
| Резюме: |
The dissertation is dedicated to the pollution with heavy metals and metalloids in a region of Northwestern Bulgaria that is historically connected with ore mining and processing. Ore mining industry is one of the main polluters of the environment the consequences of whose activities are complex and long-lasting. The introductory chapter defines the ecological problems of the region that has been researched. The necessity of extensive research of this region outlines clearly the aim concerning the up-to-date characteristic features of pollution with As and heavy metals in the Ogosta dam lake basin. It also specifies the tasks in accordance with the samples - the waters of Ogosta dam lake, the stream sediments of the Chiprovska Ogosta river basin and Ogosta dam lake, and the soils of the Chiprovska Ogosta river floodplains. Literature review contains two chapters of the text that treat the geological structure and the previous studies on the pollution in the region. The chosen methodology of study corresponds to the aim and tasks of the dissertation. The research includes three types of samples (waters, stream sediments, soil), each of which requires a specific methodological approach. The sampling of all samples is according to the Bulgarian State Standard and the preparation follows a standard scheme. The usage of sequential extraction procedure is particularly important to estimate the elements mobility under different conditions in the environment. The results of the research are organized in three chapters dealing with each of the samples. There is another summarizing chapter that treats sulfides which are the main cause of the pollution in this region. The existing data gives information about the contents of more than 30 elements in the different fractions of the sediments and soil. A statistic approach that draws up average content and quotients of correlation has been used during the processing of the geochemical results. They reveal patterns in the distribution of elements and forward to the most common heavy metals-bearing minerals. The elements proclaimed by the Law as dangerous /As, Pb, Zn, Cd, Cu, Ni, Mn/ and mineral resources of pollution are in the focus of attention. The comparison with the local background the standardnorms shows the extent to which the three types of samples have been polluted. An attempt to justify the existence of a new problem in connection to the chemical elements, not classified by the law as dangerous but which may pose an ecological threat, has been made. The data about the mobility forms of heavy metals and metalloids in the sediments and soil give more in-depth awareness of the process. The part of water-soluble form of presence, which is too low, and the high part of the residual /insoluble/ form bind with mineralogical characteristics of the ore minerals /low degree of exogenous change/ and can be explained by the normal to low base environment due to the existing carbonates. The subsequent directions for limitation of the influence of the objects of ore mining activity give the opportunity of applying the scientific results to realize economic and social effect. |
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| Описание на библ. документ: |
Кор. опис. |
| Физически характеристики: |
36 с. : с цв. ил. ; 21 см. |