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Efficiency of zeolite and apatite on the mobility of heavy metals in the soil through the Sinapis Alba as test culture
No full textZaštita i unapređenje životne sredine, posebno očuvanje i zaštita zemljišta, postao je danas jedan od najznačajnijih problema savremenog sveta. Istraživanja u ovom radu imaju za cilj ispitivanje efikasnosti dva tipa mineralnih sirovina, zeolita i apatita na imobilzaciju teških metala i sprečavanja njihovog uključenja u lanac ishrane. Ispitivani su Pb, Cd, Zn i radionuklid (U), u dozama 10 mg kg-1 Cd, 500 mg kg-1 Pb, 300 mg kg-1 Zn i 300 mg kg-1 U na zemljištima različitih fizičko-hemijskih karakteristika (peskoviti černozem i pseudoglej). Efikasnost mineralnih sirovina kroz procese adsorpcije/precipitacije polutanata u zemljištima ispitivana je preko vegetacionih ogleda sa test kulturom-biljke slačice, Sinapis Alba, preko sadržaja Pb, Cd, Zn i U u korenu i nadzemnoj masi. Rezultati ukazuju da su i zeolit i apatit, domaćeg porekla, u dozi 20 g kg-1 zemljišta, doprineli imobilizaciji ispitivanih polutanata, da njihova efikasnost zavisi od fizičko hemijskih osobina polutanta i kiselosti zemljišta, tako da njihovo korišćenje opravdava primenu u tehnologijama remedijacije kontaminiranih zemljišta a u funkciji održivosti poljoprivredne proizvodnje i proizvodnji zdravstveno bezbedne hrane.Protection and improvement of the environment, especially preservation and protection of the land, has become one of the most important problems of the modern world today. The research in this paper aims at examining the efficiency of two types of mineral raw materials, zeolites and apatites on the immobilization of heavy metals and preventing their inclusion in the food chain. Pb, Cd, Zn and radionuclides (U) were tested. In doses 10 mg kg-1Cd, 500 mg kg-1 Pb, 300 mg kg-1Zn i 300 mg kg-1U. On soil with various physico-chemical properties (sandy chernozem and pseudocley). The efficiency of mineral resources through the adsorption / precipitation of pollutants in the soil was investigated through vegetation experiments with the test culture-plant, Sinapis Alba, through the contents of Pb, Cd, Zn and U in the root and overgrowth mass. The results indicate that both, zeolite and apatite in dosage 20 g kg-1 soils, have contributed to the immobilization of the investigated pollutants, that their effectiveness depends of soils type and their acidity, kinds of pollutant, so their use is justified in the application of technologies for the remediation of contaminated soils in the function of sustainability of agricultural production and the production of healthy food
The Bond work index of limestone and andesite mixtures
No full textThis paper investigates grinding of mineral mixtures with different grindabilities in the Bond ball mill. Understanding the ore mixture grinding is of great importance in mineral processing. The energy required for crushing and grinding is presented by the Bond work index and is determined by means of Bond grindability test. This paper presents the experimental results of the Bond work index values obtained by the standard method on limestone and andesite samples, as well as composite samples made up from these ore in different weight ratios. Comparatively are shown the Bond work index values that are obtained by the mass fraction of components that make up the composite samples calculation and their differences from the real value. During the Bond work index value determining, changes in the composition of the grinding products and circulating mill charge were monitored
Microorganism activity in mine soils of black locust (Robinia pseudoacacia L.) stands on copper mine wastes in Bor, Serbia
No full textSoil microorganisms represent one of the indicators of the ecosystem development and reclamation
success in the revegetated mine waste areas. This research aims to evaluate microbiological activity in the
surface layers under the black locust stands on copper mine wastes in Bor, and to determine contribution of the
main physiological groups of microorganisms in organic matter turnover
Biosorption of heavy metals from mining influenced water
No full textHeavy industries mining and metals processing require energy, water, chemicals, and land zone. Water coming from mine sites has low pH and high concentrations of toxic metals causing a significant impact on water pollution. That creates important priority in the tightening and enforcement of environmental regulations. The need for effective and low-cost methods for the removal of metals has emerged in the development of new separation technologies. Biosorption is currently recognized as a promising technique for heavy metals removal. The present work summarizes some results obtained in application biosorption process in mining influenced water
A quick method for bond work index approximate value determination
No full textThe Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value constitutes ore characteristic and is used for industrial comminution plants designing. Determining the Bond work index value is quite complicated, time-consuming and requires trained operating personnel and therefore is subjected to errors. A quick method for the Bond work index approximate value determination, which is based on the first order grinding kinetics, is presented in this paper. Comparative experiments for the Bond work index value determination using the standard and quick procedures were carried out on samples of limestone and andesite, and on composite samples containing both ores in different mass proportions. This quick procedure can be performed with an arbitrary number of milling cycles, depending on the desired accuracy
Bioactive glass-ceramics prepared by powder sintering and crystallization of polyphosphate glass containing strontium
No full textMelt-quenching method was employed for obtaining a glass-ceramic with the following composition 42P(2)O(5). 40CaO.5SrO.10Na(2)O.3TiO(2) (mol%) glass. The crystallization and sintering behavior of glass have been studied by using DTA, HSM, XRD, FTIR and SEM methods. It was determined that the surface and volume crystallization mechanisms act simultaneously in bulk glass samples. The comparison of DTA and HSM data revealed that the sintering and crystallization processes are independent. The sintered calcium phosphate glass ceramic which contained bioactive beta-Ca-3(PO4)(2) and beta-Ca2P2O7 phases was successfully prepared. It was determined that during crystallization the primary phase in the precipitate was beta-Ca(PO3)(2). Other phases appearing in the resulting glass-ceramic were: alpha-Ca2P2O7, gamma-Ca2PO7, Ca4P6O19 and CaHPO4(H2O)(2). Crystalline phases containing Sr and Ti were not detected. SEM analysis of the glass-ceramic microstructure revealed surface crystallization of glass particles and plate-like morphology of crystal growth. The result of the in vitro bioactivity showed that no apatite layer was formed on the surface of the as-prepared glass-ceramic samples after immersion in the simulated body fluid (SBF)
Electrochemically obtained bioactive nanocomposite coating based on hydroxyapatite and chitosan loaded with gentamicin
No full textA broad spectrum antibiotic-gentamicin was loaded in a composite coating of hydroxyapatite
(HAP) with natural polymer chitosan (CS) using electrophoretic deposition (EPD) technique.
EPD was carried out at the constant voltage on pure titanium plates from an aqueous
suspension. The aim was to assemble porous homogenous coating with improved mechanical
strength and favourable antibacterial properties. HAP/CS/Gent coating was characterized by
X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR),
thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM).
Obtained results confirmed the formation of a new composite coating HAP/CS/Gent.
In the XRD spectrum of HAP/CS/Gent only characteristic crystal planes of HAP were
detected. FTIR analysis confirmed the formation of intermolecular and intramolecular
hydrogen bonds in the composite coating. TGA analysis was employed to investigate the
thermal stability of HAP/CS/Gent. The bioactivity of HAP/CS/Gent composite coating was
proved by SEM analysis. The obtained SEM micrographs indicate the biomimetic growth of
a new apatite layer after immersion in SBF. The antibiotic loaded coating (HAP/CS/Gent)
exhibited good antibacterial activity against Staphylococcus aureus and Escherichia coli,
indicating the high potential for biomedical applications. Additionally, the results have
shown that the antibacterial effect of HAP/CS/Gent was more pronounced against S. aureus
compared to E. coli
Dangerous product in households
No full textHazardous products, although used in accordance with instructions, can become dangerous when people forget the warning that this is a dangerous product or when they unconsciously and irresponsibly handling. The aim of this paper is to highlight the problems and lack of knowledge and awareness of the harmful effects of these products on human health and environment
Flotoextraction of blue water
No full textFlotation of ions and molecules represents a promising method of separating components from the solution, or in our case, gelled copper salt from the blue waters. The method of flotation of ions and molecules is basicly flotation extraction process which produces different concentration gradients of more component phase system. Different concentration gradients in the flotation extraction are due to the driving forces of the participating molecules driven by molecular interactions. More component phase system i.e. flotation pulp consists of water molecules of the solute, and a suitable reagent which has the role of connection of the liquid and gaseous phases dispersed in a biphasic system. Such a system leads to the interaction of the solute with a reagent to the formation of coagulated component in water as solvent. Separation in the polyphased system is in accordance with Van't Hoff- th equation, and spontaneously occurs in two-phase systems like gaseous-fluid, such as the system of flotation pulp. By use of the osmotic pressure in the columnn flotation machine comes to the separation of the flotation pulp to the heavy and light phase. This allows the molecules of water to form their natural distances which are only valid for molecules of pure water, apropos for heavy phase. Also, the solute forms it’s light phase, copper – surfactant salt as insoluble product. For some poliphase systems such as colloidal systems like in flotation process are sufficient atmospheric pressure conditions and for others solutions should be applied overpressure while being aerated. The paper presents the results of the research of flotation extraction of blue water i.e. copper solution content of 0.2 g/l. From the results, it is concluded that there is a possibility of purifying of blue water from copper mine tailings using the flotation extraction technology
Flotation separation of thermal heat treated ABS and PS plastics
No full textFlotation is a process that can be used for separation primary and secondary materials. The paper presents the results of a laboratory study separation of plastics waste. The aim is to extract the PS plastic from the PS/ABS mixture. Experiments were carried out in Denver cell at pH 7 in presence of MIBC as frother. The plastics were thermal threated at 100ᵒ C in order to increase the hidrophilicity of ABS surface. The results showed that PS plastics has higher flotation rate constant value, but low quality value (under 90 %) for both plastics, indicates that ABS and PS could not be successfully separated by froth flotation and which is not the case in other manuscript. Obtained results were represent by the classical model of first-order to try to describe the kinetics of plastics flotation with good correlation coefficient