specific analyses applicable to resins

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granulometry

A resin’s granulometry is determined on the wet resin, using a sifter working under water.

50 or 100 mL of resin are placed on the top screen. The protocol specified under material properties can be applied provided measurements taken for each screen are expressed in volume for the purpose of calculating percentages.

resin capacities

cations – measurement of total capacity

for low acidity cationic resins

A sample of resin that has been regenerated by saturating with hydrochloric acid is rinsed and brought into contact with a known quantity of sodium hydroxide. The excess sodium hydroxide is then titrated and the volume of resin precisely measured. The sodium hydroxide is compared with this volume to provide total capacity.

for high acidity cationic resins

A sample of resin that has been regenerated by saturating with hydrochloric acid is rinsed.

An NaCℓ solution is then percolated until it shows up as neutral on a pH paper. The displaced acidity is titrated in the effluent and the volume of resin measured precisely. The acidity released compared with this volume provides the total capacity sometimes termed, in this case, the salt-splitting capacity.

anions – measurement of salt-splitting capacity and of total capacity

low alkalinity and high alkalinity anionic resins

A sample of resin that has been regenerated by saturating with sodium hydroxide is rinsed. An NaCℓ solution is then percolated until it shows up as neutral on a pH paper. The displaced alkalinity is titrated in the effluent; compared against the volume of resin, it provides the salt-splitting capacity. This same sample of resin is then put in contact with a known amount of HCℓ. The excess acid is then titrated; the fraction consumed represents the resin’s low capacity. Total capacity is obtained by adding together the salt-splitting and low capacities thus measured.

resin pollution

organic matter

A volume of resin is brought into contact with a known volume of a solution of NaCℓ (100 g · L-1) and NaOH (20 g · L-1) for 12 hours. The TOC or permanganate oxidability of this effluent has then to be measured; compared with the volume of resin, these measurements provide the quantity of organic matter eluted, expressed as a mass of oxygen or mass of organic carbon per litre of resin.

iron

A known volume of resin is brought into contact with a known volume of hydrochloric acid and maintained at a temperature of 80 to 90° C for 30 minutes. The iron measured in this effluent is used to calculate the mass of iron eluted per litre of resin.

silica

A known volume of resin is brought into contact with a known volume of soda lye and maintained at a temperature of 80° C. The silica measured in this effluent is used to calculate the mass of silica eluted per litre of resin.