Metale ciężkie w glebie z hałdy pogórniczej w Gliwicach

The aim of this work was to carry out investigation on heavy metal content: Cu, Zn, Mn, Pb, Ni, Cd and Fe in samples of soil collected from the coal mine dump in Gliwice and evaluation of their bioavailability. Each sample was subjected to sequential extraction according to Tessier’s method. Five fractions were separated: I – exchangeable; II – carbonate; III – bound to Mn and Fe oxides; IV – bound to organic matter and V – residue. The content of Cu, Zn, Mn, Pb, Ni and Fe in particular fractions was analysed by atomic absorption spectrometry (AAS) with flame atomization, whereas Cd by AAS with electrothermal atomization. On the basis of carried out experiments it was found that in examined samples of soil the contents of metals are higher than admissible values and also higher than geometric mean reported for this region. The greatest amounts of heavy metals have been found in oxide, organic and residue fractions, in forms less available for plants. Smaller amounts were determined in more available exchangeable and carbonate fractions. It is advisable to monitor such deposits as coal mine dumps, due to the potential threat for the environment.Celem pracy było zbadanie zawartości metali ciężkich: Cu, Zn, Mn, Pb, Ni, Cd i Fe w próbkach gleby z hałdy w Gliwicach oraz określenia ich biodostępności. Dla każdej próbki gleb przeprowadzono frakcjonowanie sekwencyjne metodą Tessiera, podczas której zostaje wydzielonych 5 frakcji metali: frakcji I wymiennej, frakcji II związanych z węglanami, frakcji III związanych z tlenkami, frakcji IV związanych z materią organiczną oraz frakcji V pozostałości. Zawartość Cu, Zn, Mn, Pb, Ni i Fe w poszczególnych frakcjach oznaczono za pomocą absorpcyjnej spektrometrii atomowej z atomizacją w płomieniu, a zawartość kadmu za pomocą absorpcyjnej spektrometrii atomowej z elektrotermiczną atomizacją. Z przeprowadzonych badań wynika, że w badanej glebie znajdują się duże zawartości oznaczanych metali, często większe niż dopuszczalne, oraz większe od średnich geometrycznych dla tego terenu. Największe ilości metali ciężkich występują we frakcji tlenkowej, organicznej i w pozostałości, a więc w formach mało dostępnych dla roślin. Małe ilości występują w formach biodostępnych czyli we frakcji wymiennej i węglanowej. Pomimo to monitoring takich miejsc powinien być prowadzony, gdyż stanowią one potencjalne zagrożenie ekologiczne

Preparation and characterization of calcium cobaltite for thermoelectric application

Abstract Starting powders of CaCO 3 with different Ca:Co ratio and three different sources of cobalt (II,III) oxide were mixed and calcined at 700-1100 o C. DTA/TG, mass changes, density, grain size distribution, phase composition were examined. It has been found that phase composition of the resulted product was dependent on calcination temperature and properties of starting cobalt oxide. Three stages of cobaltite formation were established: simultaneous decomposition of CaCO 3 with Ca 3 Co 4 O 9 formation (800-900 °C), decomposition of Ca 3 Co 4 O 9 and formation of Ca 3 Co 2 O 6 (about 950 °C) and the last stage at 1050°C was dependent on starting cation ratio and source of cobalt (II,III) oxide. It has been found that total decomposition of the previous phases was observed after calcinations at 1050 °C in the batches with Ca:Co=1:1 ratio if very pure Co 3 O 4 was used for preparation. Replacement of pure Co 3 O 4 by cobalt oxide contaminated by cobalt hydroxide lead to re-formation of Ca 3 Co 4 O 9 phase at 1050 °C in 1:1 batches. Residual Co 3 O 4 and CaO was always present in calcined specimens. It seems that prolonged heat treatment did not lead to better reaction degree

Assessment of toxic and essential heavy metals in imported dried fruits sold in the local markets of Jordan

In the present study, the concentrations of nine heavy metals (Fe, Zn, Mn, Cu, Mg, Cr, Ni, Cd, and Pb) in six different imported dried fruit samples of different brands (Mangoes, black raisins, figs, apricots, plums, and cranberries) were determined by Flame Atomic Absorption Spectroscopy (FAAS) after wet digestion. Samples were collected from different stores in Amman, Jordan. The average concentration of the selected metals in the analyzed samples were found to be in the range of 1.70-8.70 (Fe), 0.15-0.72 (Zn), 0.09-0.59 (Mn), 0.07-0.46 (Cu), 2.5-53.4 (Mg), 0.06-0.15 (Cr), 0.17-0.29 (Ni), 0.01-0.05 (Cd), and 0.11-0.57 (Pb) µg/g. The highest concentrations of Fe, Zn, Mn, Mg, and Ni were found in dried figs, highest concentrations of Cr, Cd, and Pb were found in dried apricots, and highest concentrations of Cu was found in dried black raisins. The results obtained in this study showed that Mg and Fe have the highest concentrations in all analyzed samples, whereas, the lowest concentrations obtained were for Cd and Cr. The concentrations of the highly toxic metals (Pb and Cd) in the all analyzed samples were found to be below or in good agreement with the permissible limits set by different health organizations. The figures of merit obtained for the FAAS calibration curves are brilliant with good linearity (r2 > 0.99). The FAAS method was validated by determining limit of detection (LOD), limit of quantitation (LOQ), and percent recovery (%R) for all investigated metals. The results obtained in this work were compared with the literature reported values

Major and trace element contents in apples from a cultivated area of central Greece

Forty-two soil and apple samples from central Greece were collected and analyzed with regards to the content in major (Ca, Fe, K, Mg, Na, P, and S) and trace elements (As, B, Ba, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Sc, Se, Sr, Ti, and Zn). Soil samples were analyzed by inductively coupled plasma atomic emission spectrometry, while for the apples inductively coupled plasma mass spectrometry was implemented. Several elements such as As, B, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, Ti, and Zn, represent high concentrations in apples from the study area. These relatively high concentrations may be a consequence of the local geology, along with the excessive application of agricultural products such as fertilizers and agrochemicals