Solid State Phenomena Vol. 244

Abstract: Old environmental loads are priority environmental problems in Slovakia. An old environmental load is an anthropogenic constituent in landscape which has its origin in past works (for example mining and mineral processing) but in present time it can also pose risk for the environment. One of environmental loads in Slovakia is sludge bed in Slovinky. Village Slovinky is well-known for mining activities during several centuries. From the beginning copper ore was mined there, later on iron ore which was processed in the metallurgical factory in Krompachy. The mining activity in Slovinky was stopped in 1993. Flotation slurry from ore treatment plant was deposited on the sludge bed which was operated from 1968 to 1999. More than 4.8 million cubic meters of slurry is deposited there. Locality of Slovinky is included in State Remediation Program of Environmental Loads (2010-2015). The paper summarizes the actual state of knowledge about environmental impact of mineral processing and theoretical analysis of problem of environmental impact of environmental load – sludge bed in Slovinky. Experimental part of the paper is focused on study of possibilities of elimination of heavy metals in sludge bed material with the aim of improvement of the environmental quality of surveyed locality.

Abstract: Acid mine drainage contains many toxic pollutants, mainly heavy metals and sulphates, which have negative impact on the environment. This paper deal with a study of two precipitates from acid mine drainage outflowing from the abandoned mine Smolnik (Slovakia). The precipitates were created after defrosting of mine water and after the process of oxidation. After drying the precipitates were analysed by infrared spectrometry and scanning electron microscopy (SEM) with EDX analysis. Using infrared spectrometry it was found that the precipitate contained OH^-, SO₄^2- functional groups. The inhomogeneous structure of the precipitate was observed by SEM with EDX analysis. The presence of CaSO₄.2H₂O (approx. 90 %) in precipitate after defrosting was confirmed by FTIR and SEM with EDX. Particulate substances after oxidation consisted mainly iron (30.5%), oxygen (44.4 %) and sulphur (7.9 %). Complex compounds with mainly contents of iron (III), hydroxides and sulphate with crystal bound water in structure were identified.

Abstract: Particle size is a fundamental property of any sediment, which can provide important information about its nature and provenance. The particle size distribution requires precise determination using a rapid and reliable method with a high resolution. Grain size is the essential factor influencing the heavy metal contents in sediment and is the most fundamental property of sediment particles, affecting their entrainment, transport and deposition. The aim of this paper is to present the results of the effect of particle size on heavy metal (Cu, Zn, Fe, Pb and As) distributions in sediments. Dependence between the distribution of metals in the examined profile of the sediments from Ruzin water reservoir on the different size of particles and depth is unambiguous for Cu, Zn and Fe with exception of Pb and As.

Abstract: Nowadays, cement composites often contain a certain amount of waste materials, which can lead to increased heavy metals leaching. Important environmental indicator of the suitability of concrete is a leachability of chromium. In this paper, concrete samples containing special admixture based on the blast furnace slag as replacement of Portland cement (65%, 75%, 85% and 95%, respectively) as well as reference sample containing only a Portland cement were analyzed. Availability test was used to study the maximum chromium leaching from finely ground cement composites samples. The findings revealed that the leachability of hexavalent chromium from the samples containing 65 and 75 wt. % of slag-based additive was 4.59 and 1.70 times higher, respectively then the leachability of hexavalent chromium from the samples containing no slag. On the other hand, the 85 and 95 wt. % slag-containing-samples provided the Cr (VI) leachability by 26 and 41 % lower than the samples without any slag addition. Regarding the slag containing samples, the higher content of slag-based additive was in concrete sample, the lower leachability of Cr (VI) was detected.

Abstract: Industrial wastewater treatment and reuse is one of the principal tasks of present. For this purpose several physical, chemical and combined methods have been used. This paper deals with the study of sorption behaviour of natural zeolite with respect to Zn (II) and Cu (II) followed by cross-flow membrane microfiltration. The experiments realised were aimed at verification of effectiveness of ion exchange of selected metals from wastewater using zeolite – with main component clinoptilolite. The experimental data obtained were fitted using Langmuir and Freundlich isotherms. The sorption capacity was studied for zinc and copper uptake, followed by a study of microfiltration of zeolite suspension using a cross-flow microfiltration device with tubular ceramic membrane. According to experimental results the basic parameters of microfiltration process were evaluated. In comparison with other processes, the hybrid membrane microfiltration offers more effective way of water treatment.