How is ion exchange calculated?

The IEC is defined as the milliequivalent of ion-exchange groups included in a 1-g dry membrane (meq (g dry membrane)− 1). The concentration of ion-exchange groups is obtained by dividing the IEC with the water content in a 1-g dry membrane (meq (g H2O)− 1).

What is the charge of the resin in cation exchange?

negatively charged
In a cation-exchange resin all the sites are negatively charged, so that only positive ions can be separated; an anion-exchange resin has positively charged sites. Ion-exchange chromatography has become one of the most important methods for separating proteins and small oligonucleotides.

How do you calculate the ionic load of a DM plant?

A. To calculate the ionic load of water, first check the total dissolved solids, and then calculate resin proportionally. If your ionic load is less then the time of design , then you can take more water for demineralisation but you cannot change the rate of input or rate of output.

How do you calculate resin ion exchange volume?

A kilograin is equal to 1,000 grains. If you divide the capacity value by the challenge hardness, you get the number of gallons representing the throughput capacity (operating capacity). Example: 24,000 grains capacity per cubic foot challenged with 20 grains per gallon feed: (24,000/20 =) 1,200 gallons.

How do you calculate resin capacity?

The softener capacity is calculated in three simple steps:

  1. Convert water hardness from ppm to grains per US gallon. Total Hardness (ppm) = Total Hardness (gpg) Example: 118 ppm TH = 6.9 gpg;
  2. Calculate softener capacity in grains.
  3. Calculate softener capacity in gallons.
  4. Table One: Tank Size and Resin Volume.

What is cation exchange resin used for?

Cation-exchange resins are used to treat hyperkalaemia by accelerating potassium loss through the gut, especially in the context of poor urine output or before dialysis (the most effective means of treating hyperkalaemia).

What is meant by cation exchange resin and anion exchange resin?

Ion exchange resins consists of two main types, i.e., cation exchange resins, that exchange positively charged ions, such as sodium, for calcium, and anion exchange resins, that exchange negatively charged ions, such as chloride, for arsenic.

Which is the cation exchanger?

The most prevalent cation exchangers are strongly acidic resins with sulfonic acid groups (–SO3H) and weakly acidic resins with carboxylic acid groups (–COOH). In both the resins, hydrogen ions serve as exchangeable ions with metal cations.

What is capacity of ion exchange resin?

In general terms, the capacity of an ion exchange resin can be expressed as the quantity of ions that can be taken up by a specific volume of the resin. A measured quantity of caustic (NaOH) is then passed through the resin so as to totally exhaust the resin.

How do you calculate ionic load?

Calculate the ionic load per cycle in eq (concentration in meq/L times throughput in m3): Cation load [eq] = Cc · Q. Anion load [eq] = Ca · Q.

How do you calculate resin?

For a round surface, you will need to measure the diameter. Divide the diameter by 2 to calculate the radius. To calculate volume in cubic inches: (radius squared) X pi (or, 3.14159265) x (desired epoxy coating thickness). Divide by 1.805 to convert cubic inch volume to US fluid ounces.

What is the ion exchange capacity of resin?

Each litre of ion exchange resin will thus be able to treat 1100 / 4.4 = 250 litres of the hard water before having to be regenerated. In ion exchange jargon, this means that the throughput is 250 bed volumes….Operating capacity in practice.

Resin type* Total capacity Operating capacity
SBA 0.9 to 1.4 [1.2] 0.4 to 0.9

How are cation exchange resins replaced in water?

At this stage, the resin will be replaced by a fresh resin, or regenerated. If you replace all cations dissolved in water by H+ ions and all anions by OH– ions, these will recombine and form new molecules of water. To do this, you need a cation exchange resin in the H form and an anion exchange resin in the OH form.

How is the ion exchange capacity of resin expressed?

The ion exchange capacity is expressed as eq/L(equivalents per litre of resin). The unit of mole should be avoidedaltogether in ion exchange, as it does not take valence into account and brings only confusion. For reference: 1 eq = 1 mole / valence.

What kind of resin bind one type of cation?

Exchangers bind one type of cation but, when presented with a second type of cation, it may displace, and/or exchange with, the first. These resins are called cation-exchange resins. Anion-exchange resins are positively charged and bind and/or exchange negatively charged ions (anions).

How is the hardness of cation resin determined?

Hardness is given in grains/gallon or in ppm as CaCO 3. The reduction is directly related to the amount of cations present in raw water and the amount of salt used to regenerate the resin bed. Typically, 6 lb of NaCl/ft 3 (9 kg/m 3) of resin is used for regenerating strong acid cation resins.