Abstract: A process is provided for selectively removing nitrate ions from solutions containing one or more additional ions, especially at high concentrations, by contacting the solution with amine-group-containing material under conditions of high kinetics. The process is particularly suitable for stripping nitrate from solutions which have been used to regenerate anion exchange resins loaded with nitrate ions.

Abstract: Powdered synthetic polymeric resin is produced by swelling or shrinking resin particles by contact with water or an organic solvent to introduce strain within the particles and comminuting the swollen or shrunk particles by grinding them in a rotary attrition mill. This process is particularly useful for the production of powdered resins for oral consumption, for example powdered cholestyramine resin, since particle sizes such that 90% by weight and/or number is below 30 microns in average particle diameter in the wet swollen state may be achieved.