Comparison of removal characteristics of suspended particles in sulfonic and carboxylic cation exchange resins

The effect of deposited small particles on the removal characteristics of suspended corrosion products in sulfonic and carboxylic acid cation exchange resins and styrene divinyl benzene beads (S.D.B.) was studied. The surface conductivity of the resin beads was determined by measuring the impedance response with frequency for a mixture of resin beads and suspended particles. The removal performance of the resin beads at a feed linear velocity of 2.8 cm/s was in the order: sulfonic acid resins < S.D.B. < carboxylic acid resins. The removal performance of cation exchange resins depended on the kinds of ions released from resins while their counter ions were exchaged. The surface conductivity of the resin beads was in the order: sulfonic acid resins > carboxylic acid resins > S.D.B. The variations in removal characteristics in the different kind of resin beads were explained by (i) charge repellence due to deposited particles, and (ii) a decline in the effect of surface charge due to the surface conductivity of resin beads. (author)