Chemical composition of pollen with particular reference to cation exchange capacity and uronic acid content

1972 ◽  
Vol 23 (3) ◽  
pp. 263-274 ◽  
Author(s):  
A. H. Knight ◽  
W. M. Crooke ◽  
H. Shepherd
Clay Minerals ◽  
1976 ◽  
Vol 11 (2) ◽  
pp. 137-146 ◽  
Author(s):  
G. S. R. Krishna Murti ◽  
V. A. K. Sarma ◽  
P. Rengasamy

AbstractThe amorphous mineral selectively dissolved from the clay (<2 μm) fractions of twenty-six ferruginous soils contains considerable iron in addition to silicon and aluminium. SiO2/Al2O3 and SiO2/R2O3 molar ratios are between 2·03-3·52 and 1·72-2·95 respectively. The model of the amorphous ferri-aluminosilicate (AFAS) consists mainly of negatively charged tetrahedrally coordinated silica-alumina phase Si3AlO6(OH)4 containing domains of neutral FeOOH, with an outer positively charged hydroxyaluminium polymeric component [Al(OH)2.5]n.The calculated hydroxyl water content of the AFAS averages 17·8%; cation exchange capacity varies from 48·6 to 112·0 mEq/100 g and shows a negative correlation with the outer hydroxyaluminium octahedral component and a positive correlation with the ratio of the tetrahedral Si-Al component to the octahedral hydroxyaluminium component. The K-fixation capacity (1·9-6·1 mEq/100 g) of the AFAS does not appear to be related to the chemical composition. The genesis of the amorphous mineral is discussed.


2018 ◽  
Vol 3 (1) ◽  
pp. 721
Author(s):  
Dr. Cecilio Hernández B. ◽  
M.Sc. Jorge Olmos ◽  
Licda. Yahaira Espinosa

The initial results of the properties that have been determined to a sample of natural zeolite, coming from areas of volcanic activity of Panama, and that has been identified with potential for its industrial explotation, are presented. Some physicochemical properties, chemical composition and morphology were determined. A natural zeolite with an intermediate level of Si/Al (2.62), low levels of dissolved salts and a morphology with pores-shaped channels with a diameter of 5 mm are observed.Keywords: natural zeolites, chemisorption, morphology, macropores, cation exchange capacity


2010 ◽  
Vol 13 (1) ◽  
pp. 17-21
Author(s):  
Mai Thi Hoang Vo ◽  
Thach Ngoc Le

Montmorillonite is a "green" solid catalyst and support used in many organic reations. In this paper, we describe the method to prepare two acid-activated montmorillonites from Binh Thuan and Lam Dong clays. We still prepared some cation exchanged montmorillonites as Fe3+ Zn 2+ and Al 3+. The Vietnamese montmorillonites and K-10, KSF (two commercial Fluka montmorillonites) were determinated simultanneously on some physicochemical properties such as crystalline structure, chemical composition, cation exchange capacity, adsorption capacity, porisity, surface area and acidity. The results shows that the quality of Vietnamese montmorillonites are equivalent with K-10 and KSF.


2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Mardi Wibowo

Since year 1977 until 2005, PT. ANTAM has been exploited nickel ore resources at Gebe Island – Center ofHalmahera District – North Maluku Province. Mining activity, beside give economically advantages also causedegradation of environment quality espicially land quality. Therefore, it need evaluation activity for change ofland quality at Gebe Island after mining activity.From chemical rehabilitation aspect, post mining land and rehabilitation land indacate very lack and lackfertility (base saturated 45,87 – 99,6%; cation exchange capacity 9,43 – 12,43%; Organic Carbon 1,12 –2,31%). From availability of nutrirnt element aspect, post mining land and rehabilitation land indicate verylack and lack fertility (nitrogen 0,1 – 1,19%). Base on that data, it can be concluded that land reclamationactivity not yet achieve standart condition of chemical land.Key words : land quality, post mining lan


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