The natural minerals pyrite and chalcopyrite have been used as the indicator electrode sensors using acetonitrile and propionitrile as solvents. The results show the exceptional advantage of pyrite and chalcopyrite as electrochemical sensors and also the possibility of the application of these electrodes for the determination in nonaqueous solutions where glass electrode shows many defaults. The behaviour of the pyrite and chalcopyrite indicator electrodes in nitriles were checked by titrating several bases and acids of different strengths using protons and lyate ions generated by the oxidation of some gallic acid esters and dihydroxy phenols, as well as m-cresol and 3-metoxy phenol. The results obtained by using these electrodes were compared with those obtained by the application of a glass electrode under the same conditions, and good agreement, reproducibility and accuracy were obtained. The standard deviation of the determination of the investigated acids and bases was less than 0.9%. In the potentiometric titrations with pyrite and chalcopyrite indicator electrodes, the potential is instantaneously established throughout. Both electrodes can be used without any time limit or without considerable divergence in potentials.

The aim of this study was to determine the ability of roots and above-ground parts of three plant species of the Asteraceae family (Matricaria inodora L., Achillea millefolium L., Crepis setosa Haller fill.) for bioaccumulation and translocation of eight metals (Ca, Mg, Fe, Mn, Cu, Zn, Pb, Cr). Those plants were sampled directly along the lanes of the highway at the entrance into the City of Kragujevac, Republic of Serbia. The investigated metals are emitted into the air from road traffic and are deposited in the surrounding soil. Many of them are toxic to the living organism, and it is, therefore, necessary to apply effective, economical, sustainable methods for their removal from the environment. An example of such a method is as phytoremediation, based on the use of metal hyperaccumulator plants. The results of this research showed the species studied differ in the absorption, translocation and accumulation of investigated metals. They also showed that species M. inodora and A. millefolium (leaves) can be used for the phytoextraction of Ca, Mg, Fe, Mn, Cu, Zn and Cr, species C. setosa (leaves) for Ca, Mg and Cu species M. inodora (stem) for Cr. The results further indicate that all three species absorb Zn from the soil and translocate it to the stems and leaves. All three of the studied species are suitable for phytostabilization of soils loaded with Zn, but only the species M. inodora and C. setosa can be applied in phytoremediation of this metal.

This study aimed to determine the concentrations of ten metals (Mn, Ni, Ca, Mg, Fe, Zn, Cr, Pb, Cd, Cu) in the soil at depths of 10 and 20 cm and selected plant species (Populus nigra L., Fraxinus ornus L., Salix alba L., Salix caprea L.), as well as to assess the ability of these plants of metal bioaccumulation, translocation and phytoremediation on the location of the mine pit and flotation tailings of the selected mine (in the center of the Republic of Serbia). The concentrations of Pb and Cu in the investigated soil at a depth of 10 cm were above remediation values stated in the regulations of the Republic of Serbia. At the same time, the concentration of Cd, Cr, Pb and Cu was above the limit values in both of the examined soil depths, while Ni in the soil at a depth of 10 cm was above the limit value determined in the Directives of the European Union. The species F. ornus shows the ability to phytoextract Ca, species P. nigra Zn, Ca and Cd, while both Salix species have the capacity to phytoextract Zn and Ca. The results showed that species S. alba is an efficient bioaccumulator of Mn, Fe, Cr, Pb, Zn and Ca, S. caprea of Fe, Cu, Cr, Mg and Pb, and P. nigra of Mn and Cd. The bioaccumulation and translocation of the investigated elements depend on plant species and their organ. The selection of plant species adequate for remediation should take this into account.