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Abstract:In present paper, the influence of the initial pH and concentration of Pb 2+ on its adsorption by the natural (NZA) and Fe(III)-modified zeolite-alginate beads (FeA) was studied. Results showed that modification of the starting materials have a positive effect on their adsorption capacities (102 and 136 mg/g for the NZA and FeA, respectively). After encapsulation, the mechanism of lead adsorption by both adsorbents was changed and ion exchange dominates. The best adsorption was achieved for initial pH > 3.8. Cation exchange capacity, structural properties, and hydrophobicity of samples were also determined, and the presence of the alginate has no significant influence on investigated properties of samples. Experiments on wastewater from tailings of lead and zinc mine Grot, Serbia, showed that after treatment with both adsorbents, the content of the most abundant heavy metals (Pb, Zn, Hg, and Mn) significantly decreased.

Abstract:The technological process of exploitation of mineral resources and processing of mined ores to cater to the market results, among other things, in a large amount of tailings deposed on tailing ponds. Because of the chemical composition of the material, the increasing amount of waste, and the mismanagement of recovery and reclamation of ponds, these ponds have become a significant element of negative impact on the surrounding ecosystem. Economics was behind the discharging of this material, resulting in tailing ponds created in inappropriate areas. There is an ongoing process of depositing tailings on old tailing ponds, although no special attention has been paid to the subsequent effect on the environment. Application of intelligent multi-criteria analysis AHP and PROMETHEE has been performed in this paper for the purpose of ranking the degree of negative impact on the environment of tailing ponds. Analysis is performed for five tailing ponds of MMCC (Mining Metallurgy Chemical Combine) "Trepča", whereby two of the ponds are active and three inactive. The ponds are in relatively close proximity to the municipalities of Zvečan and Kosovska Mitrovica, to the north of Kosovo and Metohija, Republic of Serbia. In order to achieve the most objective results, the AHP and PROMETHEE methods were applied. By using these methods for calculations, the following ranking for the flotation tailing waste deposits was obtained, regarding their environmental impact: Žitkovac, Tvrdanski Do, Bostanište, Gornje Polje and Žarkov Potok. This result can contribute to the decision-making process of a prioritizing strategy for rehabilitation and remediation of these five flotation tailings. The analysis illustrates that application of intelligent multi-criteria analysis is a useful environmental management tool to be included in the decision-making process.

The aim of this work is to present what are the possibilities for providing Pb-Zn ore from the surrounding districts for exploitation the "CRNAC" mine. The amount of excavated ore, as well as a wellknown fact that the ore reserves are not inexhaustible, generated the need for continuation od geological exploration. Enlargement of raw material base should be expected on the indicated locations close to the active deposits of Crnac. One of the identified sites in the Crnac ore zone and the eastern part of active deposit is also the so-called district of "CRNAC-EAST".This paper presents the results of geologically explored operations obtained by interpolation of data from exploratory wells and exploratory mining operations in the district of "CRNAC-EAST".

Exploitation, development and primary extraction of the minerals result in release of the harmful substances, e.g. heavy metals, toxic gases, dirt, etc, that are often uncontrolled deposit in the environment. Those deposited and overlooked substances remain as a heritage and challenge for the coming generations that would involve abundant human, technical and financial resources for the environmental reclamation. The mining activities of the Trepča -RIF Kopaonik has both positive and negative influences within the Leposavić municipality, i.e., industrial development and environmental degradation. As a result of the mining activities the air, land and water resources both surface and underground are severely polluted. The main objective of this paper is to present adverse effects of the mineral resources (lead and zinc) exploitation and primary extraction on the Ibar River water quality degradation mainly by heavy metals. Since the heavy metals are frequently ingested by the people through the food chain and given the high toxicity of them they are crucial parameters for the water quality monitoring practices that should be carefully assessed and controlled. Thus this paper includes comprehensive analyses of the heavy metals concentration (Pb, Zn, Cu, Cd and Fe) in the Ibar River within the Leposavić municipality