King Abdulaziz City for Science and Technology, P.O. Box 6086, Riyadh 11442, Saudi Arabia.
Water Res. 2010 Jan;44(1):177-84. doi: 10.1016/j.watres.2009.09.031. Epub 2009 Oct 1.
Pilot studies were undertaken to quantify the total activity of radon that is eluted following no-flow periods from several Ra-226 adsorbents loaded to near exhaustion. The adsorbents studied included two types of barium sulphate impregnated alumina (ABA-8000 and F-1) and Dowex MSC-1 resin treated by either barium hydroxide or barium chloride. In parallel, radium loaded plain activated aluminas and Dowex MSC-1 resin were similarly investigated. The results revealed that radon was quantitatively eluted during the first few bed volumes of column operation after no-flow periods. Although similar radon elution profiles were obtained, the position of the radon peak was found to vary and depended on the adsorbent type. Radon levels up to 24 and 14 kBq dm(-3) were measured after a rest period of 72h from radium exhausted Dowex MSC-1 treated with barium chloride and F-1 impregnated alumina with barium sulphate, respectively. The eluted radon values measured experimentally were compared to those calculated theoretically from accumulated radium quantities for the different media. For plain adsorbents, an agreement better than 10% was obtained. For treated resin-types a consistency within 30% but for impregnated alumina-types high discrepancy between respective values were obtained.
开展了初步研究，以定量测定从接近耗尽的放射性镭-226 负载的几种吸附剂在无流动期间洗脱的氡总活度。所研究的吸附剂包括两种类型的硫酸钡浸渍氧化铝（ABA-8000 和 F-1）和用氢氧化钡或氯化钡处理的 Dowex MSC-1 树脂。同时，类似地研究了负载镭的普通活性氧化铝和 Dowex MSC-1 树脂。结果表明，在无流动期间后，柱操作的最初几个床体积中氡被定量洗脱。尽管获得了相似的氡洗脱曲线，但发现氡峰的位置有所变化，取决于吸附剂的类型。在镭耗尽的 Dowex MSC-1 用氯化钡处理和 F-1 浸渍的硫酸钡氧化铝处理后，分别经过 72 小时的休息期，测量到高达 24 和 14 kBq dm(-3)的氡水平。实验测量的洗脱氡值与不同介质中累积镭量计算的理论值进行了比较。对于普通吸附剂，获得了优于 10%的一致性。对于处理后的树脂类型，一致性在 30%以内，但对于浸渍的氧化铝类型，各自的值之间存在很大的差异。
