P. P. Krechetov

Ion chromatography as a tool for the investigation of unsymmetrical hydrazine degradation in soils

A new procedure for the determination of 1,1-dimethylhydrazine (UDMH) in soil samples was developed. This involves the distillation of UDMH from an alkaline suspension of soil and ion chromatographic analysis of the distillate. The separation was performed on a silica cation-exchanger column with ammonium acetate buffer solution as mobile phase and amperometric detection at +1.2 V. Hydrazine (Hy) and methylhydrazine (MH), which are decomposition products of UDMH, can be determined simultaneously. The limits of detection in aqueous solutions were 0.2, 0.5 and 1 µg L−1 for Hy, MH and UDMH, respectively. The developed technique was used for investigating the behaviour of UDMH in spills of rocket fuels on soils. It was found that the addition of 4 kg m−2 UDMH resulted in a 0.02% residue one year after the soil treatment. The vertical migration of UDMH in soil was less than 50 cm.

Transformation of unsymmetrical dimethylhydrazine in soils

The transformation of unsymmetrical dimethylhydrazine (UDMH, a propellant component) applied at a rate of 240 g/kg to different soils was studied. The kinetic regularities of a decrease in the UDMH concentration and the accumulation of its transformation products leached out from dry and wet soils were investigated 3, 10, 30, and 90 days after its application. As the UDMH enters the soil, it vaporizes, and the elevated moisture of the soils promotes an increase in the pollutant’s concentration at the initial moment; then, the concentration differences become leveled to the end of observation. It was also shown that the higher the organic matter content in the soil, the higher the UDMH concentration. However, at the end of the observations, on the 90th day, the total UDMH concentration did not exceed 0.5% of its initial content. In order to explain the UDMH behavior in the soils, one should take into account the existence of different forms of this substance and the changes in their ratios with time. The main portion of UDMH retained by the soil in the free form is transformed during the first few days. The products of the UDMH transformation, such as 1-methyl-1,2,4-triazole, formic acid dimethylhydrazide, dimethylguanidine, and dimethylamine are formed in considerable amounts, and their concentrations should be controlled in places of UDMH spills on soils.

Soil and geochemical characteristics of mountain and tundra landscapes in impact zones used for landing separated parts of launch vehicles

To properly evaluate the data received during the ecological monitoring of space-rocket activities, it is necessary to make allowance for the natural variability of the chemical properties of soils that are common for the territories used for landing separated parts of launch vehicles. This paper presents the results of the soil and geochemical studies in mountain and tundra landscapes in the Republic of Altai in the impact zone where the second stages of launch vehicles fall. Based on the obtained results and data from laboratory experimental investigations, the ecological soil buffer capacity in relation to rocket fuel is quantified for one of the monitored sites.

Soil-geochemical factors of rocket fuel migration in the landscape

The effect of different soil-geochemical factors on the migration of asymmetric dimethylhydrazine (UDMH) in the landscape has been studied. Experimental studies have been performed on soil and rock samples with specified parameters of the material composition. The effect of organic matter, acid–base properties, particle size distribution, and mineralogy on the decrease in the concentration of UDMH in equilibrium solutions has been studied. It has been found that the soil-geochemical factors are arranged in the following series according to the effect on UDMH mobility: acid–base properties > organic matter content > clay fraction mineralogy > particle size distribution.

Revegetation of areas disturbed by rocket impact in Central Kazakhstan

ABSTRACT Rocket launches are a source of anthropogenic disturbance to Central Kazakhstan ecosystems. Multistage launch vehicles (LV) are used for orbit insertion of different spacecrafts from the Baikonur cosmodrome (Republic of Kazakhstan). The launch consists of stages during which the rocket separates successively, with pieces falling to the ground along the flight route of the LV. Regions of first stage falling located in Central Kazakhstan endure the most intensive impact. First stage fallings lead to mechanical and pyrogenic disturbance and pollution by fuel components. We characterized vegetation changes at the first stage falling sites of ‘Proton-M’ rocket carriers during two growing seasons. Spontaneous revegetation by ruderal plant communities occurs after falling. First stage falling sites have lower vegetation cover and species diversity. Ceratocarpus arenarius is a dominant species in plant communities at the sites that have been affected by first stage falling. After winter rocket launches vegetation is less deteriorated at the falling sites than after spring and summer launches. The recovery process in plant communities is considerably faster at falling sites corresponding to winter rocket launches. Nomenclature: S.K. Cherepanov (1995).

Contemporary state of vegetation in Baikonur Cosmodrome and estimate of its potential resistance to impact of space-rocket activities

The actual vegetation in the territory of the Baikonur Cosmodrome (the Republic of Kazakhstan) has been mapped for the first time. The potential resistance of edificators and plant associations to the impact of space-rocket activities has been estimated based on this. Weakly and moderately resistant phytocenoses, comparatively resistant phytocenoses, and resistant ones have been ascertained to occupy 43, 18.5, and 38% of the cosmodrome’s territory.

Temperature conditions in soils as an ecological factor of ecosystem evolution

Criteria of ecological estimation of temperature conditions for functioning of land ecosystems are examined in this work. It has been shown that soil climate has a key influence on the spatial distribution of phytocenosises of the East European Plain. To characterize the temperature regime of soils, it is proposed, together with active temperatures (>10°C), to use ecologically sufficient (5–10°C) and ecologically optimal (10–22°C) temperatures. Some parameters concerning the different depths of the root layer (20 cm, 40 cm, 80 cm, 160 cm, and 320 cm) are proposed for use as the criteria of ecological estimation of the temperature regime. On the basis of the mentioned criteria, the main regularities of the temperature regime of East European Plain soils have been examined.