Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: pierwiastki niezbędne

Sortuj według:

Ogranicz wyniki do:

Changes in the concentrations of selected toxic and essential elements in ewe milk from area with a potentially undisturbed environment

Pšenková Martina, Toman Róbert, Imrich Ivan, Hluchý Svätoslav

Science, Technology and Innovation

2021

Vol. 13, no. 2

28--34

The aim of this study was to evaluate the effect of lactation on the concentration of selected essential and toxic elements in sheep milk forma area of Slovakia with potentially undisturbed environment and to find the actual contamination of selected area, in view of its environmental character. The research was conducted with 400 sheep (Tsigai breed), where the milk samples were taken during the lactation periods (early, middle and late lactation stage). Sheep were reared on the extensive pastures, reared indoors afterwards, fed with pasture ad libidum. Milk samples were collected after morning and afternoon milking. The samples of milk were analysed toxic and essential elements (Ca, Se, Mg, Zn, Fe, Cu, As, Cd, Hg, Ni, Pb) by the method of atomic absorption spectroscopy (AAS). The macro elements concentration in milk changes following the stages of lactation (p < 0.05). There was found that Ca milk concentration increased gradually in the following stages of lactation while Mg, Se, and Fe only in the last stage of lactation. With order hand, the milk concentration of Zn was the highest during summer (p < 0.05). Simultaneously the contents of essential elements (Cu) and toxic elements (As, Cd, Hg, Ni, Pb) in milk were very low, below the limit of quantification. In conclusion, ewe’s milk from potentially undisturbed environmental areas of Slovakia is safe and poses no risk to consumer health, and is suitable for use directly or in dairy processing.

Preparation and Properties of Zeolite Fertilizer Able to Slowly Release Copper

Sersen F., Cik G., Havranek E.

Chemia i Inżynieria Ekologiczna

2003

Vol. 10, nr 12

1291-1299

lt has been found that treatment of natural clinoptilolite tuff by ion exchange of CU2+ instead Ca2+ and K+ and by complexation of copper ions with thiophene oligomers, which were synthesized in microstructure of Cu-doped zeolite, enables slow release of copper into an aqueous medium. This was confirmed by the hydroponic growth of maize in the Knop nutrient medium in presence of the Cu-doped and thiophene stabilized of copper in zeolite. The zeolite treated in this way can be employed in agriculture in regions with copper-deficient soils as a slow-releasing fertilizer.

Do naturalnego tufu klinoptylolitu, na drodze wymiany jonowej, wprowadzono (zamiast Ca2+ i K+) jony CU2+, które immobilizowano na powierzchni jego mikrostruktury poprzez kompleksowanie ligandem zoligomeryzowanego tiofenu. W ten sposób otrzymano zeolit, zdolny do powolnego uwalniania miedzi do środowiska wodnego. Takie działanie zostało potwierdzane przez wykorzystanie tak przygotowanej próbki klinoptylolitu do hydroponicznej uprawy kukurydzy na pożywce Knopa. A zatem zeolity przygotowane w ten sposób mogą znaleźć zastosowanie w rolnictwie na glebach z niedoborem miedzi, jako nawóz wolno uwalniający jony tego metalu.