本文是一系列文章中的第二篇，重点介绍伊利诺伊州莱蒙市地下水中镭离子交换过程的台架和中试研究结果。（该系列的第一篇文章“评估从地下水中去除镭的各种吸附剂和膜”，发表在1988年7月的AWWA杂志上。）批次和柱研究表明，与普通阳离子相比，树脂对镭的选择性非常高。对各种树脂的衰竭再生研究表明，标准凝胶型强酸阳离子交换剂最适合循环操作中的镭去除。由于采用离子交换软化工艺，操作后硬度突破（300- 360床层体积（BV），去除镭，但不能充分利用树脂容量，循环运行时，树脂耗尽至镭穿透（2500-3000 BV），并用钠盐和钙盐再生。但由于耗尽树脂的镭再生能力较差，在钠循环的后续耗尽运行期间，镭和硬度同时突破，钙循环中观察到高镭泄漏。使用非常高的再生剂剂量（高达20倍化学计量比）可以解吸75-90%的吸附镭。钠离子交换软化工艺（在不重复使用再生剂的情况下达到硬度突破）仍然是去除镭的合适技术。 包括29个参考文献、表格和图表。

This article, the second in a series, focuses on the results of bench- and pilot-scale studies of ion exchange processes for radium removal from groundwater in Lemont, Ill. (The first article in the series, "Evaluating Various Adsorbents and Membranes for Removing Radium from Groundwater," appeared in the July 1988 issue of Journal AWWA.) Batch and column studies indicated a very high resin selectivity for radium compared with common cations. Exhaustion-regeneration studies with a variety of resins showed that a standard gel-type strongacid cation exchanger is most suitable for radium removal in cyclic operation. Because the ion exchange softening process, operated to hardness breakthrough (300-360 bed volumes (BV)), removes radium but does not fully utilize the resin capacity, cyclic runs were made with resins exhausted to radium breakthrough (2,500-3,000 BV) and regenerated with sodium and calcium salts. But because of the poor radium regenerability of the exhausted resins, simultaneous breakthrough of radium and hardness occurred during the subsequent exhaustion run of the sodium cycle, and high radium leakage was observed on the calcium cycle. Use of very high regenerant dosages (up to 20 times stoichiometric) could desorb 75-90 percent of the adsorbed radium. The sodium ion exchange softening process (operated to hardness breakthrough without regenerant reuse) continues to be an appropriate technology for the removal of radium. Includes 29 references, tables, figures.