Search

In order to study the relation of the mobility and distribution of metals between Tamarix parts and their crystal salts - soil system, different experiments were conducted with plant-rich and plant-free soils at the banks of river Nile, Aswan, Egypt. For these purposes, Tamarix top and subsoil samples near and far from the plant were collected from six different locations at the banks of river Nile. Elemental analysis of Fe, Mn, Ca, Mg, Cr, Cu, Ni, Zn, Cd and Pb in soil, and in different parts of Tamarix and their crystal salt samples was carried out by atomic absorption spectrometry, whereas Na and K were measured by atomic emission spectrophotometry. The bioavailability of metals in the soil samples was evaluated by determining their contents using sequential extraction single-step, providing higher metal concentrations in occluded Fe/Mn oxide fraction. The ratio of heavy metal concentrations in topsoil to that in subsoil enhancement (RTE) ranged from 0.67 to 4.4 and 0.22 to 4.61 for soil Tamarix and soil free from plant, respectively for all measured total element concentrations. Data indicate that the mobility expressed as transfer factor (TF) was obtained as Fe > Mg > Cr > Mn > Ca > K > Na, for Tamarix leaves. The major part of accumulated Na in Tamarix is retained in the plant leaves, while roots accumulated high concentration of Co. [ABSTRACT FROM AUTHOR]

This study aims to determine heavy-metal levels in soil from the banks of Lake Nasser, the ability of Tamarix nilotica to accumulate such metals from soil and hence its potential for phytoextraction. Soil and Tamarix samples were collected from the banks of four bights around Lake Nasser and analysed for Fe, Mn, Ca, Mg, Cr, Cu, Ni, Zn, Cd and Pb by atomic absorption spectrometry, whereas Na and K were measured by atomic emission spectrophotometry. Three different methods of extraction were used for the soil samples. Lead, copper and zinc were equally distributed between the exchangeable phase and Fe/Mn oxide-bound form, while other measured metals were mainly present in the Fe/Mn oxide fraction. With the exception of iron, all metals studied showed total concentrations within the geochemical background values. T nilotica exhibited elevated concentrations of Na (36.2–48.5mg g-1) and K (2.74–4.33mg g-1) in stems, and relatively high concentrations of Pb, Cd and Co (0.39–1.03 μg g-1, 0.24–1.3 μg g-1 and 1.94–5.3 μg g-1, respectively) are found in plant leaves. Bioaccumulation factors of Na and K (9.3 and 12.63, respectively) were high in T nilotica stems. While the bioaccumulation of Pb, Cd, Co and Ni (2870.1, 2035.4, 10.5 and 5313.2, respectively) was high in plant leaves, Fe, Mn, Ca and Mg were accumulated relatively equally in plant stems and leaves. T nilotica was found to secrete high amounts of Na, Ca and K, in addition to small amounts of all accumulated metals except Cd and Cu. [ABSTRACT FROM AUTHOR]