CALCIUM REMOVAL FROM SEA WATER BY FIXED-BED ION EXCHANGE

Calcium removal from sea water prior to evaporation permits increased temperature and concentration during evaporation. The results of laboratory studies on calcium removal by fixed-bed ion exchange are reported. Synthetic regenerants were employed, simulating in composition and total amount the waste brine from the evaporator. In actual practice, use of this brine eliminates the need to purchase regenerant chemicals. Commercial polystyrene sulfonate resins were used at room temperature, employing downflow for the softening step, and upflow for regeneration, without rinse. In multicyclic operation, the effects of particle size, bed depth, flow rate, and regenerant concentration on the degree of calcium removal have been studied. Relations for predicting resin volume and cycle time under given operating conditions are presented as an aid in calculations leading to economic optimization of the process. © 1968.