Improvement of Removing Rate of Nitrate in Drinking Water with the CARIX Process
用CARIX工艺处理饮用水的研究

The paper describes treatment of drinking water using CARIX ion exchange process. The combined application of a weakacid ion exchanger in the free acid from and an anion exchanger in the bicarbonate from provides a combined removal of nitrate, sulfate and hardness from drinking water. Carbon dioxide is used for the si-multaneous regeneration of both resins. In order to improve the regeneration efficiency of nitrate, the application of additives like CaCO3 or MgO has been studied. The dosage of different quantities of MgO has been investigated with respect to an optimization. MgO should be added at the concentrations above 0.4%. Eurthermore, the usual mixed bed was compared with a compound bed, consisting of several short single beds. Under the raw water conditions of the test, over 50 BV of water could be treated, whereas regeneration required about 5 BV of water.