P. Sequi

Sorption of atrazine and trifluralin in relation to the physio-chemical characteristics of selected soils

Abstract The sorption of two types of herbicide, atrazine (6-chloro-N2-ethyl-N4 - isopropyl-1,3,5-triazine-2,4-diamine) and trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl- p-toluidine), was studied in four different soils representative of the intensively cultivated soils of the Po Valley (northern Italy). To study the effect of the organic matter content, experiments were carried out with one of the soils after the organic matter had been removed by a sodium hypochlorite treatment. The sorption ability for atrazine and trifluralin was decreased considerably when the soil with high organic matter content was treated with sodium hypochlorite; moreover, the sorption of trifluralin also seems to be influenced by the inorganic components of the soil. In comparison to atrazine, the sorption of trifluralin by the different soils was in all cases very high. Using increasing concentrations of herbicide the sorption coefficient (Kd) for each of the four soils was calculated together with the relative sorption constant (Koc) based on the organic carbon content of the soil. The values of Kf and 1/n in the Freundlich equation for atrazine and trifluralin adsorbed by the four soils were related to the characteristics of the soils.

Heavy metal bioaccumulation in lamb and sheep bred in smelting and mining areas of S.W. sardinia (Italy)

It is widely known that anthropogenic activities strongly contributed to heavy metals contamination of the environment. For this reason, distribution of heavy metals in soils and plants around urban and industrial point sources have been the object of extensive studies. Lesser attention has been given to accumulation of heavy metals in animals bred in these polluted environments, and relatively few works are concerned with the accumulation of heavy metals through the food chain. The aim of this work is to examine the distribution of heavy metals in two contaminated environments, a smelter-refinery and a mine area situated in S.W. Sardinia. The first sampling area is located near one of the most important Pb and Zn smelting-refineries of Europe, and the second near abandoned and working mines. In this study, target organs of sheep and lamb were considered for their heavy metals accumulation. Samples of vegetation were collected throughout the vegetative period and analyzed for their Pb, Zn and Cd content. Winter forage and soil were also sampled.

Characterization of organic matter from animal manures after digestion by earthworms

The humification index (HI) values of three different manures and earthworm casts were calculated for three different extractant solutions (0.5M sodium hydroxide, 0.1M sodium pyrophosphate pH 7 and 0.1M sodium pyrophosphate plus 0.1M NaOH). The alkaline sodium pyrophosphate solution was found to be the most suitable because of both its extraction efficiency and the quality of the organic matter extracted which allows a good characterization of the stabilization degree attained by composting. Neutral sodium pyrophosphate extracts also show characteristic HI values for different samples but lower extraction efficiencies. The HI values for sodium hydroxide extracts show only little differences between manures and composts. The good correspondence found between HI data and isoelectric focusing (IEF) patterns confirmed on one side that humification indexes give a quantitative measure of the humification degree, on the other side that IEF is a suitable technique in order to obtain qualitative informations on organic matter stabilization in earthworm casts.

Anomalous contents of heavy metals in soils and vegetation of a mine area in S.W. Sardinia, Italy

Samples of soils and vegetation from the mining area of South-West Sardinia (Italy) were analyzed for Pb, Zn, Cd, and Cu content. The area (more than 100 km2) is inhabited by many thousands of people; land utilization includes mainly grapes on some small plains and permanent sheep pasture on the hills. The levels of Pb, Zn, and Cd were found to be exceptionally high in most samples. Lead concentration was up to 71000 μg g−1 in the soils and 4000 jig g−1 in vegetation; Cd concentration was found up to 665 μg g−1 in soils and 26.5 μg g−1 in vegetation. The heavy metal content of some soil samples was highly variable. Data show that Pb is easily absorbed by plant roots and translocated to foliage. In spite of the high heavy metal level, no signs of toxicity were apparent in vegetation.

Heavy Metal Content in Xylem Sap (Vitis Vinifera) from Mining and Smelting Areas

AbstractNo data are available on the content of heavy metals in the xylem sap of grapevines growing in contaminated areas. The aim of this work was to obtain data on the concentration of Pb, Zn, Cd and Cu in the xylem sap of grapevine (Vitis vinifera) cultivar Monica (ungrafted), growing near contaminated sites: a smelter, an abandoned and an active mine, and to investigate relationships between xylem sap mineral composition and the heavy metal content of the soil. The concentrations of Pb, Zn, Cd and Cu in the sap were enhanced compared to that of the soil, ranging from 4.3 to 611.4 µg Pb

Prion protein interaction with soil humic substances: environmental implications

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2D electrophoresis of humic substances: Application of a high resolution technique to polyanionic polydisperse systems.

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