scholarly journals The application of diffusive gradient technique (DGT) for assessment of changes in Cd, Pb, and Zn mobility in rhizosphere

2011 ◽  
Vol 51 (No. 12) ◽  
pp. 532-538 ◽  
Author(s):  
Z. Fischerová ◽  
J. Száková ◽  
D. Pavlíková ◽  
P. Tlustoš

Diffusive Gradient in Thin Films (DGT) technique was applied to determine Cd, Pb and Zn concentrations in rhizosphere of four different plant species: hyperaccumulator Penny-cress (Thlaspi caerulescens J. et C. Presl), trees with a good accumulation capacity willow (Salix dasyclados Vimm.) and poplar (Populus nigra L.) and crop maize (Zea mays L.). Moreover, the effect of two chelating agents (ethylendiaminetetraacetic acid – EDTA, and S,S-ethylendiaminedisuccinic acid – EDDS) on element mobility in rhizosphere like soil was investigated. DGT was able to register even small changes in heavy metal concentrations in rhizosphere according to individual crop and/or soil treatments. A particularly significant effect of EDTA application to enhance solubility of metals bound to solid phase into the soil solution was observed resulting in increased concentrations of mobile metals in rhizosphere. The suitability of DGT technique for evaluation of heavy metal behavior in the environment was demonstrated with reasonable results.

Geologija ◽  
2008 ◽  
Vol 50 (4) ◽  
pp. 237-245 ◽  
Author(s):  
Audronė Jankaitė ◽  
Pranas Baltrėnas ◽  
Agnė Kazlauskienė

2016 ◽  
Vol 5 (10) ◽  
pp. 4933
Author(s):  
Sabia Sultana ◽  
A. K. M. Nur Alam Siddiki ◽  
Md. Rokonujjaman ◽  
M. Niamul Naser ◽  
Abdus Salam ◽  
...  

The heavy metal concentration (e.g., Mn, Zn, Pb and Ni) were determined in soft tissues and shells of freshwater mussels (Lamellidens marginalis) at the various sites of Dhanmondi lake, Dhaka, Bangladesh between the period April, 2010 and March 2011. The heavy metal concentrations in shells and soft tissues of freshwater mussels were tended to vary significantly among sampling points and seasons in Dhanmondi Lake. Distribution of heavy metals in shell and soft tissue of Lamellidens marginalis followed the order Mn>Zn>Pb>Ni, respectively. According to the t-test, level of manganese, zinc and lead under investigation between shell and tissue showed statistically significant differences [Mn: t=-11.387; df=16; P=0.000; Zn: t=-2.590; df=16; P=0.020 and Pb: t=-2.8679; df=16; P=0.011].


Author(s):  
Jako S. Eensalu ◽  
Kaia Tõnsuaadu ◽  
Jasper Adamson ◽  
Ilona Oja Acik ◽  
Malle Krunks

AbstractThermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III) (1), a precursor for Sb2S3 thin films synthesized from an acidified aqueous solution of SbCl3 and KS2COCH2CH3, was monitored by simultaneous thermogravimetry, differential thermal analysis and evolved gas analysis via mass spectroscopy (TG/DTA-EGA-MS) measurements in dynamic Ar, and synthetic air atmospheres. 1 was identified by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) measurements, and quantified by NMR and elemental analysis. Solid intermediates and final decomposition products of 1 prepared in both atmospheres were determined by X-ray diffraction (XRD), Raman spectroscopy, and FTIR. 1 is a complex compound, where Sb is coordinated by three ethyldithiocarbonate ligands via the S atoms. The thermal degradation of 1 in Ar consists of three mass loss steps, and four mass loss steps in synthetic air. The total mass losses are 100% at 800 °C in Ar, and 66.8% at 600 °C in synthetic air, where the final product is Sb2O4. 1 melts at 85 °C, and decomposes at 90–170 °C into mainly Sb2S3, as confirmed by Raman, and an impurity phase consisting mostly of CSO 2 2− ligands. The solid-phase mineralizes fully at ≈240 °C, which permits Sb2S3 to crystallize at around 250 °C in both atmospheres. The gaseous species evolved include CS2, C2H5OH, CO, CO2, COS, H2O, SO2, and minor quantities of C2H5SH, (C2H5)2S, (C2H5)2O, and (S2COCH2CH3)2. The thermal decomposition mechanism of 1 is described with chemical reactions based on EGA-MS and solid intermediate decomposition product analysis.


Author(s):  
Liping Li ◽  
Yuqing Zhang ◽  
James A. Ippolito ◽  
Weiqin Xing ◽  
Chen Tu

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshifumi Imajo ◽  
Takashi Suemasu ◽  
Kaoru Toko

AbstractPolycrystalline Ge thin films have attracted increasing attention because their hole mobilities exceed those of single-crystal Si wafers, while the process temperature is low. In this study, we investigate the strain effects on the crystal and electrical properties of polycrystalline Ge layers formed by solid-phase crystallization at 375 °C by modulating the substrate material. The strain of the Ge layers is in the range of approximately 0.5% (tensile) to -0.5% (compressive), which reflects both thermal expansion difference between Ge and substrate and phase transition of Ge from amorphous to crystalline. For both tensile and compressive strains, a large strain provides large crystal grains with sizes of approximately 10 μm owing to growth promotion. The potential barrier height of the grain boundary strongly depends on the strain and its direction. It is increased by tensile strain and decreased by compressive strain. These findings will be useful for the design of Ge-based thin-film devices on various materials for Internet-of-things technologies.


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