What 3 factors affect the selectivity of ion exchangers?
Substances
- Ion Exchange Resins.
- Ions.
- Solvents. Water.
How do you choose resin for ion exchange?
(4) a resin shall be chosen according to the ingredients of the impurities in the original water. Such as more organic substances in the original water, or removal of the radius of the ion, should choose the larger diameter of the resin. Try to choose high-strength porous resin.
What are the properties of ion exchange resin?
Ion exchange resin properties
- Particle size.
- Capacity.
- Moisture.
- Dry matter.
- Specific gravity.
- Bulk density.
- Effect of bed compression.
- Optical aspect.
What is breakthrough capacity of ion exchange resin?
The average breakthrough capacity was found to be 2.17 mg NH4 per gram for the resin.
What is resin selectivity?
The selectivity coefficient of resins is defined in the ion exchange reactions page. The affinity of the resin for an ion is governed by the size of its hydrated form as well as its charge. The larger the ion, the more the resin bead must expand to accommodate it in the structure.
Why resin is used in ion exchange chromatography?
Ion exchange resins are used to soften water by replacing the cations with sodium ions (and possibly the anions with chloride ions) of sodium chloride. They may also be used to demineralize water where the cations are replaced by H+ ions and the anions are replaced by OH− ions.
What will be the order of selectivity of ion?
Selectivity coefficients can also be used to determine the order of elution in column operation. In a demineralizer (H-cycle operation), sodium with a relative affinity of 1.56 will elute before ammonium with an affinity of 2.01, which is followed by potassium, with an affinity of 2.28.
What are the characteristics of a good ion exchanger?
Basic Characteristics of Ion Exchange Resins
- Appearance.
- Particle Size.
- Reversible Swelling.
- Moisture.
- Density.
- Total capacity.
What is resin in ion exchange?
ion-exchange resin, any of a wide variety of organic compounds synthetically polymerized and containing positively or negatively charged sites that can attract an ion of opposite charge from a surrounding solution.
How is resin capacity determined?
Total capacity is actually determined on a dry-resin basis as meq/dry gm and converted to wet values (meq/mL) based on moisture content of the resin. Tests are typically run with H+/Na+ exchange rather than Ca++/Na for cation. Ion exchange systems work by exchanging ions on a one-for-one equivalency basis.
How do you calculate resin capacity?
How do you calculate resin capacity?
- Convert water hardness from ppm to grains per US gallon. Total Hardness (ppm) = Total Hardness (gpg) Example: 118 ppm TH = 6.9 gpg;
- Calculate softener capacity in grains.
- Calculate softener capacity in gallons.
- Table One: Tank Size and Resin Volume.
What is a selectivity coefficient?
A selectivity coefficient is the equilibrium constant for the reaction of displacement by one ligand of another ligand in a complex with the substrate. Binding selectivity is of major importance in biochemistry and in chemical separation processes.
What is the selectivity coefficient of resin?
Effectively, these selectivity coefficients are a measurement of a resins preference for an ion. The greater the selectivity coefficient, the greater the preference for the ion. For example, a strong acid cation resin with 8% crosslink has a selectivity coefficient for sodium vs. hydrogen of 1. 56, while the selectivity coefficient for calcium vs.
How to determine the interdiffusion coefficient of ion exchange resin?
One piece of information needed is the interdiffusion coefficient that describes the rate of exchange within the ion ex change resin bead. This parameter Is determined in the laboratory by obtain ing exchange rate data for the particular system desired. This work is a study of this experimentally determined interdiffusion coefficient.
What is ion exchange resin?
Ion exchange resin is a cross-linked porous polymer substance containing functional (ionogenic) groups with mobile ions, which may be replaced with ions of the same charge dissolved in the surrounding liquid media. Structure of ion exchange resins
How to determine the resin concentration of the entering ion?
Graphical integrating the rough reactor data of the exchange flux allows determination of the resin concentration of the entering ion, , with time. As was pointed out in Section A of Chapter IV, the rate of flow past the resin beads must be increased until the condition of particle diffusion is controlling.