Kushnareva O.P., Kanygina O.N.
ION-EXCHANGE PROPERTIES OF NATURAL MONTMORILLONITE CLAY CONTAINING ORENBURG REGION ^{[№ 9 ' 2017]}
Clays are used in the production of paper, paints, drilling fluids, cleaning of petroleum products and in many other directions. A lot of research has been done on the hydrophilic, sorption and ion-exchange properties of clay materials. However, there is very little information on the properties of clays in the Orenburg region. Of interest is the study of ion exchange processes occurring on the surface of natural non-enriched montmorillonite containing clays of the Orenburg region. The influence of high-temperature treatment on the pH and ion-exchange properties of aqueous suspensions containing particles of natural clay of the Orenburg deposit in sizes from 160 to 630 microns was investigated. In order to separate the physical and chemical processes occurring at high temperatures in clay minerals, a series of successive stepwise firing was performed in the temperature range from 300 to 900° C with a holding time of 2 hours at each temperature. The pH values of clay suspensions after this temperature action vary nonmonotonically from 8.90 in the initial sample to 12.46 after calcination at 900° C. According to the results of potentiometric titration, the ion-exchange capacity is calculated as a function of pH. When the pH is changed from 3.5 to 7, a significant increase in the ion exchange capacity is observed. The transition to the alkaline zone sharply weakens the ion-exchange properties of the clay. In the pH range from 7 to 9, ion exchange capacity is reduced and becomes insignificant. Temperature treatment does not affect the preservation of ion-exchange properties of clay. The authors convincingly explain the results obtained by the loss of moisture during heating and the phase transformations that occur, as well as the chemical composition of the clay studied. In their opinion, the presence in the clay of a large number of iron, copper and cobalt ions in an alkaline medium leads to the formation of strong hydroxocomplexes of various composition in the montmorillonite structure, which hinders ion exchange.

Kushnareva O.P., Perekrestova E.N.
EFFECT OF DIFFERENT SALT CONCENTRATIONS OF COPPER AND LEAD ON THE CHLOROPHYLL CONTENT AND THE CARBON CONTENT IN LEAVES ^{[№ 10 ' 2015]}
The article is devoted to the problem of the influence of different concentrations of copper and lead on chlorophyll formation and accumulation of carbon in the leaves of plants. The urgency of the topic, the choice of objects for research and applied techniques. Quantitative results obtained for barley and peas. Contains graphic material and links to bibliographical sources. Used theoretical concepts on the mechanisms of influence of heavy metals on plants for data analysis.

Perekrestova E. N., Efremov I. V., Kushnareva О.Р.
USING THE METHOD OF REGISTRATION OF THE DELAYED FLUORESCENCE FOR THE EVALUATION OF THE TOXIC INFLUENCE OF SALTS OF HEAVY METALS ON WHEAT SEEDS ^{[№ 10 ' 2013]}
In this paper, based on registration of the delayed fluorescence kinetics, the authors have developed a methodology of evaluation of the toxic effects of salt solutions of copper, zinc, cobalt, Nickel on wheat seeds. For the analysis of the obtained curves were used theoretical concepts on the mechanisms of delayed fluorescence and a correlation between the toxic effects of heavy metals and parameters of delayed fluorescence.

Kushnareva O.P., Ephremov I.V., Perekrestova E.N.
APPLICATION OF THE METHOD OF REGISTRATION DELAYED CHLOROPHYLL FLUORESCENCE OF ALGAE TO ASSESS THE QUALITY OF NATURAL WATERS ^{[№ 12 ' 2011]}
In article authors offer a technique of biotesting of natural waters on the basis of registration of the slowed down fluorescence of a chlorophyll of microseaweed. Results of application of this technique for various reservoirs are resulted. Theoretical positions about mechanisms of the slowed down fluorescence for the analysis of the received curves are used. Correlation dependences between parameters of the slowed down fluorescence and a chemical compound of natural waters are established.

Perekrestova E.N., Efremov I.V., Kushnareva О.Р.
ESTIMATION OF TOXIC ACTION OF HEAVY METALS ON SEEDS OF WHEAT A METHOD OF THE DELAY FLUORESCENCE ^{[№ 12 ' 2011]}
In this work and validated method for assessing biophysical toxic action of salt solutions of nickel, zinc, copper and cobalt in wheat seeds of the Orenburg region, based on recording the kinetics of delayed fluorescence. Comparing the performance curves of delayed fluorescence of the control data were obtained by the ratio, to assess the effect of cations of heavy metals on wheat seeds.

Efremov I.V., Kuzmin O.N., Kushnareva O.P., Perekrestova E.N.
INTEGRAL CHARACTERISTICS OF MIGRATION FEATURES OF SOIL-PLANTS SYSTEMS ^{[№ 12 ' 2009]}
Abstract. The article considers issues of appraisal of heavy metals migration of in soil-plant systems. The authors present the migration process of metals in soil-plant system as a stationary Markov’s process. On the basis of this approach integral indicator allowing appreciating the soil-plant system on their migratory ability is theoretically justified. The results of the integrated appraisal of soil-plant systems are given in this work.