Competitive Sorption of Arsenate and Phosphate on Different Clay Minerals and Soils

2002 ◽  
Vol 66 (6) ◽  
pp. 1788-1796 ◽  
Author(s):  
Antonio Violante ◽  
Massimo Pigna
Keyword(s):  
Clay Minerals ◽  
Competitive Sorption

Hydrated form of some clay minerals observed using a film sealed environmental cell

1978 ◽  
Vol 36 (1) ◽  
pp. 72-73
Author(s):  
N. Kohyama ◽  
K. Fukushima ◽  
A. Fukami
Keyword(s):  
Clay Minerals ◽  
Morphological Changes ◽  
Carbon Film ◽  
Electron Microscopic Observation ◽  
Adsorbed Water ◽  
Electron Microscopic ◽  
Hydrated Form ◽  
Thin Carbon ◽  
Environmental Cell ◽  
Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

Colloidal systems in soils

1994 ◽  
Vol 52 ◽  
pp. 64-65
Author(s):  
J. Thieme ◽  
J. Niemeyer ◽  
P. Guttman
Keyword(s):  
Clay Minerals ◽  
Polymeric Materials ◽  
Spatial Arrangement ◽  
High Specific Surface Area ◽  
Turnover Rates ◽  
Colloidal Systems ◽  
Chemical Conditions ◽  
Aggregation Phenomena ◽  
Iron And Manganese ◽  
Soil Colloids

In soil science the fraction of colloids in soils is understood as particles with diameters smaller than 2μm. Clay minerals, aquoxides of iron and manganese, humic substances, and other polymeric materials are found in this fraction. The spatial arrangement (microstructure) is controlled by the substantial structure of the colloids, by the chemical composition of the soil solution, and by thesoil biota. This microstructure determines among other things the diffusive mass flow within the soils and as a result the availability of substances for chemical and microbiological reactions. The turnover of nutrients, the adsorption of toxicants and the weathering of soil clay minerals are examples of these surface mediated reactions. Due to their high specific surface area, the soil colloids are the most reactive species in this respect. Under the chemical conditions in soils, these minerals are associated in larger aggregates. The accessibility of reactive sites for these reactions on the surface of the colloids is reduced by this aggregation. To determine the turnover rates of chemicals within these aggregates it is highly desirable to visualize directly these aggregation phenomena.

Mineral nitrogen isotope signature in clay minerals formed under high ammonium environment conditions in sediment associated with ammonium-rich sediment-hosted hydrothermal system

2018 ◽  
Vol 52 (4) ◽  
pp. 317-333 ◽  
Author(s):  
Jaeguk Jo ◽  
Toshiro Yamanaka ◽  
Tomoki Kashimura ◽  
Yusuke Okunishi ◽  
Yoshihiro Kuwahara ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Hydrothermal System ◽  
Nitrogen Isotope ◽  
Mineral Nitrogen ◽  
Isotope Signature

DISTRIBUTION OF THE CLAY MINERALS IN SURFACE SEDIMENTS OF THE SOUTH CHINA SEA AND THEIR PROVENANCE

2010 ◽  
Vol 30 (4) ◽  
pp. 57-66 ◽  
Author(s):  
Qian GE ◽  
Fengyou CHU ◽  
Jingpu LIU ◽  
Yuansheng DU ◽  
Zuo XUE ◽  
...  
Keyword(s):  
South China Sea ◽  
Clay Minerals ◽  
South China ◽  
Surface Sediments ◽  
The South China Sea ◽  
The South ◽  
China Sea

DISTRIBUTION PATTERN OF CLAY MINERALS IN SURFACE SEDIMENTS OF SOUTH YELLOW SEA AND THEIR PROVENANCE

2011 ◽  
Vol 31 (3) ◽  
pp. 11-16 ◽  
Author(s):  
Xianhong LAN ◽  
Xianjun ZHANG ◽  
Xinbo LIU ◽  
Rihui LI ◽  
Zhixun ZHANG
Keyword(s):  
Distribution Pattern ◽  
Clay Minerals ◽  
Yellow Sea ◽  
Surface Sediments ◽  
South Yellow Sea
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