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1.
The concentrations and distribution of 137Cs in alluvial soils (Fluvisols) of the upper and middle reaches of the Markha River in the northwest of Yakutia and 226Ra and 238U in alluvial soils within the El’kon uranium ore deposit in the south of Yakutia have been studied. It is shown that the migration of radiocesium in the permafrost-affected soils of Yakutia owing to alluviation processes extends to more than 600 km from the source of the radioactive contamination. The migration of 137Cs with water flows is accompanied by its deposition in the buried horizons of alluvial soils during extremely high floods caused by ice jams. In the technogenic landscapes of southern Yakutia, active water migration of 238U and 226Ra from radioactive dump rocks. The leaching of 238U with surface waters from the rocks is more intense than the leaching of 226Ra. The vertical distribution patterns of 238U and 226Ra in the profiles of alluvial soils are complex. Uranium tends to accumulate in the surface humus horizon and in the buried soil horizons, whereas radium does not display any definite regularities of its distribution in the soil profiles. At present, the migration of 238U and 226Ra with river water and their accumulation in the alluvial soils extend to about 30 km from the source. 相似文献
2.
N. E. Latynova 《Eurasian Soil Science》2010,43(3):348-353
The spatial-temporal features of the radioactive contamination of terrestrial ecosystem components caused by the deterioration
of the multibarrier protection of regional radioactive waste storages of the State Research Center of the Russian Federation-Leipunskii
Institute of Physics and Power Engineering at the input of radionuclides into the soil and ground water were studied. The
composition of the radioactive contamination was determined, and the hydrological and geochemical processes resulting in the
formation of large radioactive sources were described. The natural features of the radioactive waste storage areas favoring
the entry of 90Sr, 137Cs, and 226Ra into the soils and their inclusion in the biological turnover were characterized. The directions of the horizontal migration
of 90Sr, 137Cs, and 226Ra and the sites of their accumulation within the superaquatic and aquatic landscapes of a near-terrace depression were studied;
the factors of the 90Sr accumulation in plants and cockles were calculated. The results of the studies expand the theoretical concepts of the mechanisms,
processes, and factors controlling the behavior of radionuclides at the deterioration of the multibarrier protection of radioactive
waste storages. The presented experimental data can be used for solving practical problems related to environmental protection
in the areas of industrial nuclear complexes. 相似文献
3.
4.
The accumulation and redistribution of 137Cs in natural ecosystems within the 30-km impact zone of the Smolensk nuclear power plant (SNPP) are analyzed. It is shown
that the radioactive pollution of this territory is mainly due to the Chernobyl-derived radioactive fallout. However, the
radioactive decay of 137Cs from the Chernobyl disaster is partly compensated for by the 137Cs technologic emission from the SNPP. The highest rate of the vertical migration of 137Cs is typical of the bog phytocenoses and deciduous forests. The components of biota may be ranked by their capacity for 137Cs accumulation as follows: higher fungi > mosses > herbs and shrubs > trees. The organisms and their parts that may serve
as bioindicators of the modern radioactive contamination of the territory have been identified. These are the assimilative
organs and bark of the trees, various fern species among herbs, sphagnum mosses and Pleurozium schreberi (among mosses), and Typolius felleus among higher fungi. 相似文献
5.
A. I. Scheglov O. B. Tsvetnova E. P. Popova 《Moscow University Soil Science Bulletin》2016,71(2):83-87
Accumulation and distribution of 137Cs by the root systems of forests in the radioactive contamination zone of Bryansk oblast have been discussed. It has been found that the phytomass and distribution of roots of pine and birch trees along the soil profile in the studied BGCs differ considerably. The specific activity of 137Cs in the roots changes depending on their diameter: the lowest specific activity is observed in small fractions of the roots, and the highest one in large fractions. It has been shown that the contribution of roots in the total reserves of 137Cs in the soil layer of 0–50 cm of various biogeocenoses is different: the largest contribution is characteristic for birch forests (1.66%) with variation of this parameter in separate soil layers from 1.12 to 3.53%, while the contribution for pine forests is lower (0.97%) with the variation from 0.82 to 7.5%. The contribution of roots to the overall contamination of soils in the studied plant communities increases with depth. 相似文献
6.
Pits of sandy alluvial soils were studied in different parts of the floodplains of the Iput River and its tributary the Buldynka River near the settlement of Starye Bobovichi (Bryansk oblast). The 137Cs content in the soil horizons varied from 0.01 to 31.2 Bq/g reaching the maximum in the initially polluted layers buried at depths of 6 to 40 cm. Radiocesium was found in all the particle-size fractions with its predominate concentration in the finest fractions. The specific 137Cs activity in the fractions of <1, 1–5, 5–10, and >10 μm comprised 44.1 ± 11.5; 33.3 ± 7.6, 20.9 ± 4.9, and 2.4 ± 0.6 Bq/g of soil. However, the contribution of the coarse (>10 μm) fractions to the total radiocesium pool in the soils (19–60%, or 34 ± 2% on the average) was comparable with that of the clay fraction (16–71%, or 38 ± 3% on the average), because of the predominance of the sand-size fractions in the soils. The highest coefficient of variation with respect to the relative contribution of particular fractions to the total soil pool of 137Cs was characteristic of the fraction of 5–10 μm; in the other fractions, it varied from 31 to 41%. The portion of 137Cs bound with the finest fractions increased in the deeper layers. The total 137Cs activity in the polluted horizons of the soils was mainly determined by its concentration in the clay fraction (Spearman’s coefficient of rank correlation (r) for the moderately polluted horizons comprised 0.926 at n = 14). It was experimentally proved that clay particles, upon the destruction of organic films on their surface, could readsorb the released radiocesium for a second time. 相似文献
7.
A close negative correlation between the biological availability of 90Sr and 137Cs for agricultural crops and the content of exchangeable calcium in soils has been revealed in a field experiment performed for soddy-podzolic loamy sandy soil. The efficiency of soil saturation with exchangeable calcium regarding 90Sr discrimination is much higher in soils with a low supply of plants with this nutrient. For the bulk of the studied crops, the minimal biological availability of 90Sr is registered at 1200–1400 mg/kg (6.0–7.0 mg-equiv./100 g) of the exchangeable calcium content in the soil and that of 137Cs is registered at 1000–1100 mg/kg (5.0–5.5 mg-equiv./100 g). The crop productivity varies significantly depending on the exchangeable calcium content in the soil. 相似文献
8.
A. S. Tulina V. M. Semenov N. N. Tsybul’ka T. P. Shapsheeva A. A. Zaitsev T. V. Arastovich 《Eurasian Soil Science》2010,43(10):1109-1119
The role of mineralization of soil organic matter (SOM) in the mobilization of 137Cs was estimated on the basis of data on the biokinetic fractionation of the organic matter of soddy-podzolic sandy-loam and
peat bog soils and on the coefficients of the soil-to-plant transfer of radiocesium under field conditions. The peat bog soils
were richer than the soddy-podzolic soils in the total organic carbon (by 7.9–23.8 times), the potentially mineralizable carbon
(by 2.4–6.5 times), and the carbon of the microbial biomass (by 2.9–4.6 times). The agricultural use of the soddy-podzolic
and peat bog soils led to a decrease in the SOM mineralization capacity by 1.1–1.8 and 1.4–2.0 times, respectively. Simultaneously,
the portions of the easily, moderately, and difficultly mineralizable fraction of the SOM active pool changed. The coefficients
of the 137Cs transfer from the peat bog soils to plants were 3.3–17.6 times higher than those for the soddy-podzolic soils. The content
of 137Cs in plants grown on the peat bog soils was 2–65 times higher than that in the mobile (salt-extractable) soil pool by the
beginning of the growing season. Strong positive linear correlations were found between the coefficients of the soil-to-plant
transfer of 137Cs and the total content of the SOM, the content of the microbial biomass, the content of the potentially mineralizable carbon,
and the intensity of its mineralization. It was concluded that the decisive factors controlling the intensity of the 137Cs transfer from mineral and organic soils into plants are the SOM content and its mineralization potential. The mineralization
of the SOM is accompanied by the release of both 137Cs and mineral nitrogen; the latter facilitates the transfer of radiocesium into plants. 相似文献
9.
B. F. Aparin E. V. Mingareeva N. I. Sanzharova E. Yu. Sukhacheva 《Eurasian Soil Science》2017,50(12):1395-1405
Data on the concentrations of natural (226Ra, 232Th and 40K) and artificial (137Cs) radionuclides and on the physicochemical properties of chernozems sampled in different years are presented. In 1952, upon the creation of the Penza-Kamensk state shelterbelt, three deep (up to 3 m) soil pits were examined within the former arable field under two-year-old plantations of ash and maple along the transect crossing the territory of the Beloprudskaya Experimental Station of the USSR Academy of Sciences in Volgograd oblast. The samples from these pits were included into the collection of dated soil samples of the Dokuchaev Central Soil Science Museum. Five pits were examined along the same transect in 2009: three pits under shelterbelts (analogues of the pits studied in 1952) and two pits on arable fields between the shelterbelts. In the past 57 years, certain changes took place in the soil structure, bulk density, and the content and composition of humus. The salt profile of soils changed significantly under the forests. The comparison of distribution patterns of natural soil radionuclides in 1952 and 2009 demonstrated their higher contents at the depth of 10–20 cm in 2009 (except for the western shelterbelt). Background concentrations of natural radionuclides in parent materials and relationships between their distributions and the salt profiles of soils have been determined; they are most clearly observed is the soils under shelterbelts. Insignificant contamination with 137Cs (up to 34 Bq/kg) has been found in the samples of 2009 from the upper (0–20 cm) horizon. The activity of 137Cs regularly decreases from the east to the west; the highest concentrations of this radionuclide are found in the topmost 10 cm. This allows us to suppose that 137Cs was brought with aerial dust by eastern winds, and the shelterbelts served as barriers to the wind flow. 相似文献
10.
A. D. Fokin S. P. Torshin Yu. M. Bebneva R. A. Gadzhiagaeva L. G. Taldykina 《Eurasian Soil Science》2016,49(4):412-421
The increased concentration of an element in plant biomass compared to the soil mass is an essential condition for the differentiated spatial distribution and status of the element on the aggregate level. Two forms of this differentiation have been revealed for 137Cs and 90Sr. Transfer of 137Cs from plant roots and concentration on the surface of soil aggregates have been established experimentally. Indirect data also point to the potential localization of 137Cs on the surface of intraaggregate pores. The effect of radionuclide concentrating on the outer and inner surfaces of aggregates is due to the rapid and strong fixation of cesium microamounts by mineral soil components. 137Cs from the surface of aggregates is more available for the repeated uptake by plant roots than from the intraped mass. The distortion of this spatial differentiation mainly occurs during the reaggregation of soil mass, which in turn decreases the availability of the radionuclide to plants. For 90Sr, its elevated concentration in the form of organic residues has been revealed in the inter- and intraaggregate pore space. However, due to the high diffusion rate, 90Sr is relatively rapidly (during several months under pot experimental conditions) redistributed throughout the entire volume of soil aggregates and its major part gradually passes into the phase of humic compounds, to which the radionuclide is bound by exchange sorption. The high level of the next root uptake (higher than for 137Cs by one to two orders of magnitude) favors the permanent renewal of loci with increased 90Sr concentrations in the inter- and intraaggregate pore space in the form of plant residues. 相似文献
11.
O. B. Tsvetnova D. N. Lipatov A. I. Shcheglov 《Moscow University Soil Science Bulletin》2007,62(1):29-35
Structural changes in the 137Cs contamination fields in natural and agroecosystems of the northern forest steppe (the remote zone of the Chernobyl accident) were studied. It was shown that the lateral and vertical distribution of 137Cs in soils of different biogeocenoses depends on the features of functioning biogeocenoses and the spatial variation of the initial fallout. The effect of biogeocenosis on the spatial variation of the contaminant distribution increases with time. At present, the variation of primary distribution in soils of agrocenoses is changing. The soils of forest biogeocenoses have retained the features of primary distribution, particularly in the upper 0-to 5-cm sublitter layer. The 137Cs penetration depth is greatest in the soils of layland and functioning agrocenosis and least in the soils of forest biogeocenoses. 相似文献
12.
A. I. Shcheglov O. B. Tsvetnova A. A. Kasatskii 《Moscow University Soil Science Bulletin》2011,66(3):123-128
The features of the biological cycle of 137Cs and 39K in the remote period after Chernobyl fallouts are considered on the example of forest ecosystems of Bryansk woodland. It
is demonstrated that the maximum amount of 137Cs in the total phytomass is concentrated in wood, the minimum amount of 137Cs, in the external bark layers; for the annual production, in assimilating organs and the external bark layers, respectively.
The distribution of 39K in the total phytomass and the annual production is almost identical to that of 137Cs. The arrival of 137Cs to the soil with litter in pine and birch forests has recently been equal approximately to 50% of the capacity of the biological
cycle. It mostly arrives with the assimilating organs (needles and leaves). In pine forests the return of 39K into the soil with litter is closest to that observed for 137Cs. 相似文献
13.
Motohiko Kondo Hideo Maeda Akitoshi Goto Hiroshi Nakano Nobuharu Kiho Tomoyuki Makino 《Soil Science and Plant Nutrition》2013,59(1):133-143
Pot and field experiments were conducted to clarify the effect of soil exchangeable potassium (K) and cesium-137 (137Cs) on 137Cs accumulation and to establish soil index in rice (Oryza sativa L.). Four paddy soils in Fukushima Prefecture, Japan, showing different transfer factors for radioactive Cs derived from the accident of Fukushima Daiichi Nuclear Power Station in the field were compared in terms of 137Cs accumulation in rice in a pot experiment. 137Cs accumulation in shoots and brown rice widely varied among soils with the transfer factor ranging from 0.018 to 0.068 for shoots and 0.004 to 0.065 for brown rice. 137Cs concentration in brown rice and shoots tended to decrease with higher levels of soil exchangeable K, and they were more closely related to the exchangeable Cs/K ratio. Similar relationships between the Cs/K ratio and Cs accumulation in plants were obtained for the stable isotope cesium-133 (133Cs). The distributions of 137Cs and 133Cs in grains were also similar and variable among soils. The transfer factors obtained in pot experiments mostly agreed with field observations. The results imply that the exchangeable 137Cs/K can be a potential soil index to estimate 137Cs accumulation in rice. 相似文献
14.
A. V. Panov R. M. Aleksakhin P. V. Prudnikov A. A. Novikov A. A. Muzalevskaya 《Eurasian Soil Science》2009,42(4):445-457
The dynamics of 137Cs uptake by crops and the influence of rehabilitation measures on the accumulation of this radionuclide in agricultural products have been estimated by the example of southwestern regions of Bryansk oblast. In 20 yr after the Chernobyl NPP accident, three stages of a decrease in the concentration of 137Cs in the crops can be distinguished. At present (in 15–20 yr after the accident), the rate of the decrease in the concentration of 137Cs in some crops corresponds to the half-decay period of this radionuclide. 相似文献
15.
The role of the mineralogy of the clay fraction and the physicochemical properties of alluvial soils in the floodplain of the Iput River and its tributary the Buldynka River (in the region of the settlement of Starye Bobovichi in Bryansk oblast) in the distribution and immobilization of radioactive isotope 137Cs from the atmospheric fallout after the Chernobyl accident was studied. The soils had a sandy texture; a significant variation in the content of amorphous iron oxides (0.1–0.77%) and labile manganese (11.2–193 mg/kg), the cation exchange capacity (6.1–54.2 meq/100 g soil), and the base saturation (29–100%) was common; an appreciable content of X-ray amorphous mineral substances in the clay fraction (<1 μm) enriched with organic carbon (7.7–13.1%); the predominance of trioctahedral hydromicas (Me=50%) in the clay fraction; and the presence of fine-disperse quartz and lepidocrocite. The specific activity of the 137Cs in the clay fraction of the moderately and strongly contaminated layers increased with the increasing portion of smectite formations and (or) hydromicas. On the whole, the presence of the clay fraction favored a decrease in the 137Cs mobility (the correlation between its content and that of exchangeable cesium was r=?0.608, n=17). However, the portion of exchangeable radiocesium (extracted with 1 M CH3COONH4, 1:10) had a tendency toward an increase with increasing content of hydromicas in the clay fraction. Thus, the minerals of this group were a potential source of exchangeable 137Cs in the soils. The significant role of amorphous and mobile iron forms in the immobilization and migration of radiocesium in the secondary contaminated horizons of the alluvial soils was revealed. 相似文献
16.
《CATENA》2004,57(1):15-34
Concentrations in the soil of anthropogenic and natural radionuclides have been investigated in order to assess the applicability of the 137Cs technique in an area of typical Mediterranean steep slopes. This technique can be used to estimate net soil redistribution rates but its potential in areas with shallow and stony soils on hard rock lithology have not been evaluated so far. In this research, the validity of using this technique in stony shallow soils at very steep slopes is discussed together with the relations between radionuclide concentrations and other soil properties, lithology, slope morphology and land use in a Mediterranean environment. Both natural Potassium-40 (40K), Uranium-238 (238U), Thorium-232 (232Th) and anthropogenic Caesium-137 (137Cs) radionuclides have been determined in samples taken along slope transects on uncultivated serpentinite soils and cultivated gneiss soils. In addition to the radionuclide concentrations, parameters such as slope position, slope angle, aspect, soil depth, surface stone cover, moss, litter, vegetation cover, soil crust, stone content and bulk density have been quantified.All the natural radionuclides 40K, 238U, 232Th show significantly higher concentrations in the gneiss than in the serpentinite soils, opposed to the 137Cs concentration, which is found significantly higher in the serpentinite soils probably because of the difference in clay mineralogy. The exponential decreasing depth distribution of 137Cs and its homogeneous spatial distribution emphasise the applicability of the 137Cs technique in this ecosystem.Lithology determines the concentration of natural and anthropogenic radionuclides. Land use determines the relations between 137Cs concentration/inventory and some soil characteristics. Higher 137Cs concentration and inventory are associated with higher percentages of vegetation cover, higher percentage of stones in the soil and higher values of soil bulk density in cultivated gneiss soils. Slope morphology and land use influence the soil redistribution at slope scale. The gneiss slopes show a zonation of four to five areas of differential erosion/accumulation processes corresponding with more regular slopes and soil redistribution due to water erosion and to tillage translocation and erosion. The serpentinites, as an example of a more unstable slope type, show more erosion areas with less accumulation downslope and soil redistribution due to water erosion. 相似文献
17.
The dynamic method was proposed for studying the kinetics of 137Cs selective sorption by the measurement of the 137Cs activity directly in the sorbent solid phase. A thin layer of the sorbent in a disposable syringe membrane filter (MF)
was eluted with a 137Cs solution containing K+ and Ca2+ ions with a gradual decrease in the solution flow rate from 6 to 0.2 cm3/min. The activity of the sorbed 137Cs was determined periodically by placing the same MF in the detector well of a Wizard 1480 gamma counter. It was shown that
the masses of the sorbent and water in the MF had no effect on the efficiency of the 137Cs measurement. A linear relationship between the RIP(K) value and the square root of the time for the period between 4 and
30 days was revealed using this method. The relative increase in the RIP(K) with time changed by 6 times (from 0.034 to 0.208
days−0.5) for the soils and by 20 times (from 0.008 to 0.153 days−0.5) for the mineral sorbents. The RIP(K) values measured for the interaction of soddy-podzolic soils with 137Cs during 24 hours using the standard limited volume method were lower than the values determined by the proposed dynamic
method for the interaction period of 30 days by 50–100%. 相似文献
18.
Elena M. Korobova Vitaly G. Linnik Justin Brown 《Journal of Soils and Sediments》2016,16(4):1279-1287
Purpose
The purpose of this study was to compare the distribution of the most significant medium and long-lived radioisotopes, i.e., 60Co, 137Cs, and 152Eu, in granulometric and organic fractions of alluvial soils downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC), Russia, to reveal natural patterns of their behavior and accumulation.Materials and methods
Soil samples collected at different elevations and depths in a floodplain of the Yenisey River downstream from the KMCC (20–250 km) were subjected to granulometric analysis by dry screening and a modified Petelin method. Fractions <0.05 mm were collected by a pipette method. Radionuclide activity in the different soil layers and in their fractions was determined using a spectrometer equipped with an HPGe detector. Concentration of total C (Ctot) and C of carbonates (Ccarb) was determined using a CHN analyzer before and after elimination of carbonates, organic C (Corg) being calculated as the difference between the obtained values. Organic fractions were separated by saturation of the air-dry sample with 0.1 M NaOH and further precipitation of humic acid from filtrate by 1 M HCl at pH 1. The separation resulted in three fractions of the fulvic acids, humic acids, and the residue containing the denuded mineral phase and the refractory organic residue. The selected bulk samples and fractions were analyzed for radionuclide activity.Results and discussion
Based on earlier results, the distribution of the pelite (<0.01 mm) and aleurite (0.01–0.1 mm) fractions in alluvium and soil samples have been analyzed to evaluate the grain-size contribution to radionuclide fixation. A positive correlation between radionuclide activity and the portion of pelite fraction was established for 60Co and 152Eu, while 137Cs accumulation was not related with this fraction. In organic matter (OM) extracts, more than 90 % of 137Cs, at proportions similar to those attributable to 238Th and 40K, were associated with the residue fraction, while 72 % of 152Eu and 46 % of 60Co were found in the mobile fraction of the low molecular fulvic acids. In successive layers of the soil vertical profile, approximately 94 % of the 152Eu variation may be explained by a linear model with Corg and Ccarb values as independent variables.Conclusions
Different associations of 137Cs, 60Co, and 152 Eu with particulate and organic fractions in river sediments and floodplain soils could be explained by the dominating discharge form (water soluble or particulate), affinity to organic substances of different mobility, sorption by minerals and their aggregates, and chemisorption.19.
K. M. Mehta H. S. Shankaranarayana C. J. Jaisinghani 《Soil Science and Plant Nutrition》2013,59(5):32-38
The soils of Rajasthan vary from desert sand to heavy clay with all intermediate stages like sandy loam, loam and clay loam. The last two textural groups are more prevalant on the eastern, northeastern and southeastern part of the Aravallies which run almost in the middle of the State from southeast to northeast. The latter groups of soils have more potential from the point of agricultural development in the State. These soils are widely termed as alluvial soils which is a general term to indicate the nontaxonomic group of soils that have parent material of alluvial origin, Riecken 17, Kelloog 8 has referred to the soils developed from the alluvium as classified under variety of world soil groups. In our country many of the alluvial soils have not yet been studied from the soil genesis point of view as a measure to classify the soils under taxonomic groups. Ray Chawdhary and Mukerji 15, concluded that the alluvial soil groups of our country are ill defined and the classification of these soils need more study. Basu 3 was able to distinguish the genetic characteristics of the soils of Deccan. Agrawal and Mukherji 1) established that distinct genetic soil types have come into expression under Gangetic alluvium. Agarwal 2 has concluded about the three types of soils in the toposequence with precipitated calcium throughout, zone of calcium accumulation in the bottom of the profile and soils free of calcium, and suggests that the soils of Gangetic plain be called as derived from alluvium. A process of reclassifying the alluvial soil series into taxonomic groups is a common trend in the United States since the last two decades. 相似文献