Typha latifolia is a plant species widely used for phytoremediation. Accumulation, localization and distribution of Pb and mineral nutrients were investigated in roots, rhizomes and leaves of Typha latifolia grown at 0, 50, 100 and 250 mM Pb concentrations in a pot experiment under controlled conditions. Bulk elemental concentrations were determined by X-ray fluorescence (XRF) spectroscopy whereas micro-proton-induced X-ray emission (micro-PIXE) was used for element localization in root and rhizome tissues. Gradual increase in bulk Pb concentrations was observed in Typha latifolia roots and rhizomes treated with increasing Pb concentrations, however in rhizomes Pb concentrations were an order of magnitude lower than in roots. In leaves Pb concentrations were around the limit of detection for XRF (B20 mg g1). An increase in concentration of K and Ca in roots, rhizomes and leaves, of iron and zinc in roots and leaves, and of Mn in rhizomes was observed either at 50 and/or 100 mM Pb treatments, whereas for K and Ca in roots, rhizomes and leaves, Fe and Zn in roots and leaves and Mn in rhizomes, or at 250 mM Pb treatment the increase was seen for concentrations of Fe and Zn in rhizomes and Cu in roots. Mn concentrations decreased with Pb treatments in roots and leaves. Element localization using micro-PIXE analysis demonstrated Pb accumulation in epidermal and cortical tissues of treated roots and rhizomes, while in endodermis and vascular tissues Pb was not detected. A displacement of Ca from epidermal to cortical tissues was observed in Pb treated roots and rhizomes, pointing to cell wall immobilization of Pb as one of the tolerance mechanisms in Typha latifolia. High level of colocalization of Pb with P (r = 0.60), S (r = 0.37) and Zn (r = 0.70) was observed in Pb treated roots, while in rhizomes colocalization with the mentioned elements was still positive, but not that prominent. These results indicate that Pb may form complexes with phosphorus and sulfur compounds in roots and rhizomes, which may also represent attraction sites for binding Zn. Because of its large root and rhizome surface area acting as main sites for Pb adsorption, Typha latifolia may represent potentially efficient plant species for phytoremediation of Pb contaminated soils and waters.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 25615911Time dependence of mass loss from the test surface was measured together with concentrations of inhalable particulate matter (PM10) and black carbon (BC) in the vicinity of the test surface for wind velocities ranging from 1 - 18 m/s at 0.20 m above the centre of the test surface. Threshold wind velocities ut.20 were measured for four different size fractions of coal and for three different fractions of iron ore stored at the terminal, and for hydrated alumina - a strong dust emitter. The same set up was employed to study the suppression of dust emitted by the finest coal fraction (d ( 3 mm) upon watering of the dry test surface. By CFD modelling the similarity of our size limited test track was examined with respect to a flat terrain situation. The analysis shows that measured wind velocity thresholds for different fractions are consistent with the predictions of the Greley-Iversen scheme. Although the dusting potential of the non-fractioned (realistic) coal sample reflects dusting potentials of its fractions, measurements show that the former cannot be estimated simply by a weighted average of different fractions. Watering (1.0 l/m2/h) of the coal surface reduced the mass outflow by one hundred times with respect to the dry coal surface when u.20 = 11.3 m/s. Alternatively, stabilisation of the iron ore surface can be achieved by a single act of watering; upon drying agglomeration of hematite particles occurs and a firm crust forms on the surface strongly reducing further dusting.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 25703975''Multi-photon excitation of He doubly excited states'' is the title of our proposal to perform an experiment at a new free-electron-laser facilty FERMI that was submitted on the occasion of the first international call for experiments. FERMI is the first fully tunable FEL light source reaching extremely high power densities of several 10^14 W/cm^2 in the VUV energy region. The proposal, that was written on the basis of our previous extensive experience with the metastable helium experiments was accepted granting the (international) group (PI is dr. M. Žitnik) an access to the LDM experimental station at the begining of 2013.
D.01 Chairing over/coordinating (international and national) projects
In 2012 we have obtained for the first time an opportuinity to open a 3-year MC PhD post in our reseach programme. The candidate will be dealing with development of the x-ray spectrometer having a medium spectral resolution and efficiency. The design is based on the use of the policapillary lens coupled to the flat crystal and its expected characteristics are somewhere between the semiconductor (SiLi) and curved crystal spectrometer.
D.08 Management and development of research activities
This achievement demonstrates the existence of the critical mass of researchers in the programme that know the experimental tehniques at synchrotrons very well so that they (can) fulfil the growing needs of other domestic (foreign) research groups in the need of such techniques (understanding behavior of new materials, functioning of plant tissues) to reach the sychrotron beamlines and actually perform the experiments there.
F.03 Increased qualifications of the research and development staff