Search results
Results from the WOW.Com Content Network
Cation-exchange capacity is measured by displacing all the bound cations with a concentrated solution of another cation, and then measuring either the displaced cations or the amount of added cation that is retained. [1] Barium (Ba 2+) and ammonium (NH 4 +) are frequently used as exchanger cations, although many other methods are available. [4] [5]
Using methods developed by Frank Spedding in the 1940s, ... In soil science, cation-exchange capacity is the ion-exchange capacity of soil for positively charged ions ...
Ion Exchange Resins(IER) have been widely used especially in medicines due to its high capacity and the uncomplicated system of the separation process. One of the synthetic uses is to use Ion Exchange Resins for kidney dialysis. This method is used to separate the blood elements by using the cellulose membraned artificial kidney. [56]
Cation exchange capacity is the soil's ability to remove cations from the soil water solution and sequester those to be exchanged later as the plant roots release hydrogen ions to the solution. [103] CEC is the amount of exchangeable hydrogen cations (H + ) that will combine with 100 grams dry weight of soil and whose measure is one ...
Ion-exchange resin beads. An ion-exchange resin or ion-exchange polymer is a resin or polymer that acts as a medium for ion exchange, that is also known as an ionex. [1] It is an insoluble matrix (or support structure) normally in the form of small (0.25–1.43 mm radius) microbeads, usually white or yellowish, fabricated from an organic polymer substrate.
The cation exchange principle was discovered by Thomas Way and John Bennet Lawes at Rothamsted Experimental Station in the 19th century. In 1892 Oscar Loew observed that both calcium and magnesium can be toxic to plants when there is an excess of one and a deficiency of the other, thus suggesting there may be an optimal Ca:Mg ratio.
The degree to which a given amount of lime per unit of soil volume will increase soil pH depends on the buffer capacity of the soil (this is generally related to soil cation exchange capacity or CEC). Most acid soils are saturated with aluminum rather than hydrogen ions. Soil acidity generally results from hydrolysis of aluminum. [4]
Montmorillonite is a subclass of smectite, a 2:1 phyllosilicate mineral characterized as having greater than 50% octahedral charge; its cation exchange capacity is due to isomorphous substitution of Mg for Al in the central alumina plane. The substitution of lower valence cations in such instances leaves the nearby oxygen atoms with a net ...