No abstract

Sediments are normally the final pathway of both natural and anthropogenic components produced or derived from the environment. Sediment quality is a good indicator of pollution in the water column, where heavy metals and other organic pollutants tend to concentrate. Metals are introduced in aquatic systems as a result of the weathering of soils and rocks, from volcanic eruptions, and from a variety of human activities involving the mining, processing, or use of metals and/or substances that contain metal pollutants. Heavy metal concentration in the water column can be relatively low in some cases, but the concentrations in the sediment may be elevated. The presented work aimed to investigate the pollutant levels of some heavy metals (Fe, Mn, Al, Cu, Zn, As, Cd, Pb) in the water and sediments related to acid mine drainage (AMD) produced from an abandoned sulphide mine in Smolnik in Eastern Slovakia. A metal pollution index was used to compare the total content of metals at five sampling stations. The level of partitioning of the metals between the surface water and sediments in the area was calculated using Partition coefficients and the correlation coefficients between the metal pairs in both media were calculated by a Pearson coefficient.

Abstract:The analytical method based on the high-per formance liquid chromatography coupled with UV detection (HPLC/ UV) for determination of selected antioxidants (i.e., esculetin, scopoletin, 7-hydroxycoumarine, r utin, xanthotoxin, 5-methoxypsoralen and quercetin) in plant material was developed. Pressurised fluid extraction (PFE) and ultrasonic extraction (USE) methods for the isolation of these compounds from ten real plant samples were used. Both extraction methods were optimised and compared to each other. For the proposed HPLC/UV method the LOQ values (limit of quantification) in the range from 22.7 (xanthotoxin) to 97.2 ng mL -1 (r utin) were obtained. For all extracts the antioxidant capacity based on the reduction of free 2,2-diphenyl-1-picr ylhydrazyl radical (DPPH) was also determined. Results ranged from 82.04 to 94.43% of DPPH radical inhibition for PFE method and from 76.01 to 89.94% in the case of USE method.

Abstract:The analytical microextraction methods of gas chromatography coupled with flame ionisation detector (GC-FID) for determination of selected essential oils in herbs were proposed. Two microextraction methods for the isolation of essential oils from plants such as Lavandula spica L., Melissa officinalis L., Mentha piperita L. and Salvia officinalis L. were used. The methods of solid-phase and single-drop microextractions, were optimised and compared. The obtained LOD values for all studied essential oils were found to be within 2.5-20.5 µg for SDME and 57.0-139.8 µg for SPME method per 100 g of dried sample leaves. The appropriate LOQ values were then 8.4-68.4 µg for SDME and 189.8-466.1 µg for SPME of target analytes per 100 g of dried sample leaves.© Versita Warsaw and Springer-Verlag Berlin Heidelberg.

Mining is probably the most common activity that fundamentally impacts the country. The problems connected with the extraction of sulphide ores arise especially during the final stage of mining, closure and abandonment of the extraction area, when the conditions for the generation of strong acid water are most likely to occur. With respect to the diversity of compounds in acid mine drainage (AMD) and its low pH values it is hard to find an effective and inexpensive "active" treatment process. Recently, numerous approaches have been studied for the development of cheaper and more effective technologies, both to decrease the amount of heavy metals and to improve the quality of the treated effluent. Adsorption has become one of the alternative treatments; in the recent years, the search for low-cost adsorbents that have metalbinding capacities has intensified. Adsorption of heavy metals (Cu and Zn) from single-component aqueous solutions onto non-modified poplar sawdust, hemp shives and peat has been studied using the batch-adsorption techniques. For this purpose, solutions with different concentrations ranging from 10 to 150 mg/L have been used. The study was carried out to examine the adsorption capacity of the low-cost waste materials as potential biosorbents for the removal of heavy metals from acid mine drainage. The adsorption isotherms could be better fitted by the Langmuir model (values of the correlation factor range from 0.974 to 0.997). The values of the separation factor (RL) in the present study were found to be within 0.037-0.728, indicating the favorable adsorption process. From the comparison of maximum sorption capacities, it is evident that the best adsorption properties are exhibited by the hemp shives, and copper is overall better adsorbed than zinc (Qmax = 12.84 mg/g and 8.28 mg/g for copper and zinc, respectively). The results indicate that these freely abundant, low-cost waste materials can be treated as economically viable for the removal of metal ions in acidic conditions.