Exchange capacity: This is the weight of ions that can be retained per unit volume ( or sometime per unit weight ) of the exchange material concerned
Bed volume: volume per hours of liquid to be treated / volume of resin
Ion flux: Bed volume * salinity of water
Regeneration level: weight of reagent used / volume of ion exchange material
Regeneration rate: 100* (grams-equivalents of regenerating reagent)/ (grams-equivalents of the eluted ions)
Regeneration efficiency: This is the opposite ratio above
Ion leakage: This is the concentration of unwanted ion left in the treated liquid
Breakthrough: This is the maximum permissible ion leakage requiring the production cycle to be shut down.
Attrition: mechanical wear of the exchanger grains as they are being used.