Influence of clay mineral type and organic matter content on the uptake of239Pu and241Am by plants

1981 ◽  
Vol 59 (1) ◽  
pp. 75-82 ◽  
Author(s):  
B. N. Vyas ◽  
K. B. Mistry
1958 ◽  
Vol 38 (2) ◽  
pp. 173-188 ◽  
Author(s):  
J. E. Brydon ◽  
H. Heystek

Six profiles taken from the dikeland areas of Nova Scotia were examined chemically and mineralogically. The mineralogy of the various layers was similar within and between profiles, except that the reddish layers contained goethite while the grey layers did not. The latter were very strongly acidic and had an unusually high organic matter content due to burial of undecomposed vegetation by tidal sediments. While they contained no goethite, they had a significant amount of "free iron". It is proposed that where sufficient organic matter was available the grey layers were produced by anaerobic bacterial reduction of the reddish iron oxides.Quartz was the predominant non-clay mineral associated with mica, feldspar and chlorite. The clay fraction consisted of illite with characteristics of muscovite, chlorite similar to "swelling" chlorite, kaolinite and montmorillonite.


2016 ◽  
Vol 95 (3) ◽  
pp. 269-281 ◽  
Author(s):  
M. Koenen ◽  
J. Griffioen

AbstractSamples from Rupel Clay across the Netherlands were analysed for the assessment of its heterogeneity in geochemistry and mineralogy. X-ray fluorescence (XRF) and bulk and clay fraction X-ray diffraction (XRD) analyses of 152 samples from 17 different cores are presented and statistically interpreted. The results show a wide variation in the quartz, feldspar, clay mineral and carbonate content between the different samples. Factor analysis showed that the main variance between the samples can be explained by the clay mineral and quartz concentration, the carbonate content and pyrite plus organic matter. In the south of the Netherlands, the Rupel Clay is more quartz-rich and coarse grained. In addition, the clay is heterogeneous, varying with location and depth, consistent with observations for Belgium Boom Clay. Towards the north, the Rupel Clay becomes more clay-rich, finer grained and more homogeneous, both laterally and with depth. In addition, the clay has a relatively high carbonate and organic matter content. The pyrite content does not show any trends with location and depth. The differences between north and south are explained by the variations in depositional setting within the southern North Sea Basin.


2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaohua Jiang ◽  
Songtao Wu ◽  
Lianhua Hou ◽  
Jinyou Zhang ◽  
Modi Guan ◽  
...  

Pore structure is a major factor affecting the storage space and oil-bearing properties of shales. Mineralogy, organic matter content, and thermal evolution complicate the pore structures of lacustrine shales. In this study, the porosity evolution of organic-matter-rich shales from the Cretaceous Nenjiang Formation in the Songliao Basin, Northeast China, are investigated using thermal simulation experiments and in-situ scanning electron microscope analysis. Three findings were obtained as follows: 1) The pore system of shales from the Nenjiang Formation is dominated by inter-granular dissolution pores of plagioclase and intra-granular pores of illite-smectite mixed layers. Few organic-matter pores are observed. 2) New pores developing during thermal evolution are primarily organic matter pores and clay mineral pores, with diameters greater than 18 nm. Clay mineral pores with diameters of 18–50 nm are the principal contributors to porosity at temperatures between the low maturity stage and the oil-generation window, and organic matter pores with diameters of greater than 50 nm comprise the majority of pores generated between the gas-generation window and the high-/over-mature stages. 3) Porosity increases continuously with maturity, and the pore system varies at different maturity stages. Porosity evolution is controlled by illite content and organic matter abundance. Total pore volume correlates positively with illite content but negatively with organic matter abundance. These findings could provide guidance on shale oil evaluation in the Songliao Basin and assist in the ‘sweet-spotting’ of lacustrine shale systems across China.


Author(s):  
O. A. Lipatnikova

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.


Author(s):  
Amita M Watkar ◽  

Soil, itself means Soul of Infinite Life. Soil is the naturally occurring unconsolidated or loose covering on the earth’s surface. Physical properties depend upon the amount, size, shape, arrangement, and mineral composition of soil particles. It also depends on the organic matter content and pore spaces. Chemical properties depend on the Inorganic and organic matter present in the soil. Soils are the essential components of the environment and foundation resources for nearly all types of land use, besides being the most important component of sustainable agriculture. Therefore, assessment of soil quality and its direction of change with time is an ideal and primary indicator of sustainable agricultural land management. Soil quality indicators refer to measurable soil attributes that influence the capacity of a soil to function, within the limits imposed by the ecosystem, to preserve biological productivity and environmental quality and promote plant, animal and human health. The present study is to assess these soil attributes such as physical and chemical properties season-wise.


2020 ◽  
Vol 117 (3) ◽  
pp. 351-365
Author(s):  
J. Pijlman ◽  
G. Holshof ◽  
W. van den Berg ◽  
G. H. Ros ◽  
J. W. Erisman ◽  
...  

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1326
Author(s):  
Calvin F. Glaspie ◽  
Eric A. L. Jones ◽  
Donald Penner ◽  
John A. Pawlak ◽  
Wesley J. Everman

Greenhouse studies were conducted to evaluate the effects of soil organic matter content and soil pH on initial and residual weed control with flumioxazin by planting selected weed species in various lab-made and field soils. Initial control was determined by planting weed seeds into various lab-made and field soils treated with flumioxazin (71 g ha−1). Seeds of Echinochloa crus-galli (barnyard grass), Setaria faberi (giant foxtail), Amaranthus retroflexus (redroot pigweed), and Abutilon theophrasti (velvetleaf) were incorporated into the top 1.3 cm of each soil at a density of 100 seeds per pot, respectively. Emerged plants were counted and removed in both treated and non-treated pots two weeks after planting and each following week for six weeks. Flumioxazin control was evaluated by calculating percent emergence of weeds in treated soils compared to the emergence of weeds in non-treated soils. Clay content was not found to affect initial flumioxazin control of any tested weed species. Control of A. theophrasti, E. crus-galli, and S. faberi was reduced as soil organic matter content increased. The control of A. retroflexus was not affected by organic matter. Soil pH below 6 reduced flumioxazin control of A. theophrasti, and S. faberi but did not affect the control of A. retroflexus and E. crus-galli. Flumioxazin residual control was determined by planting selected weed species in various lab-made and field soils 0, 2, 4, 6, and 8 weeks after treatment. Eight weeks after treatment, flumioxazin gave 0% control of A. theophrasti and S. faberi in all soils tested. Control of A. retroflexus and Chenopodium album (common lambsquarters) was 100% for the duration of the experiment, except when soil organic matter content was greater than 3% or the soil pH 7. Eight weeks after treatment, 0% control was only observed for common A. retroflexus and C. album in organic soil (soil organic matter > 80%) or when soil pH was above 7. Control of A. theophrasti and S. faberi decreased as soil organic matter content and soil pH increased. Similar results were observed when comparing lab-made soils to field soils; however, differences in control were observed between lab-made organic matter soils and field organic matter soils. Results indicate that flumioxazin can provide control ranging from 75–100% for two to six weeks on common weed species.


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