错流超滤技术在海水胶体态铀、钍、镭同位素和有机碳研究中的应用

陈敏; 郭劳动; 黄奕普; 高众勇; 蔡毅华; 蔡明刚

错流超滤技术在海水胶体态铀、钍、镭同位素和有机碳研究中的应用

1.
厦门大学海洋系, 厦门 361005
2.
Department of Oceanography, Texas A & M University, 5007 Avenue U, Galveston, TX 77551, USA

基金项目: 国家自然科学基金资助项目(编号:49706069);国家自然科学基金委员会国际合作基金资助项目(98-美014).

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出版历程
- 收稿日期: 1999-05-10
- 修回日期: 2000-03-24

Application of the cross-flow ultrafiltration technique to the study of colloidal uranium, thorium, radium isotopes and organic carbon in seawater

1.
Department of Oceanography, Xiamen University, Xiamen 361005
2.
Department of Oceanography, Texas A & M University, 5007 Avenue U, Galveston, TX 77551, USA

摘要

摘要: 建立了由预过滤装置、蠕动泵、中空纤维超滤膜(AmiconH10P10-20,标称截留分子量10KDa)和连接管组成的错流超滤系统,利用荧光标记的40KDa葡聚糖和已知放射性活度的²³⁴Th示踪剂评估了超滤膜的截留和吸附性质,探讨了²³⁴Th在超滤过程中的渗透行为,考查了该系统用于实际海水样品时铀、钍、镭同位素和有机碳的质量平衡状况.结果表明,10Kda中空纤维超滤膜对40Kda葡聚糖具有良好的截留效率(85%),而吸附损失率为18%.铀、钍、镭同位素和有机碳在超滤过程中均达到极佳的质量平衡,回收率R=95%～98%,优于大多数文献报道的值.²³⁴Th在超滤过程中的渗透行为可以很好地用渗透模型加以描述.研究组分胶体态含量占“溶解”态含量的份额大小顺序如下:钍同位素、有机碳、镭同位素约等于铀同位素,这与钍为强颗粒活性元素、铀和镭为水溶性元素的地球化学性质相吻合.
- 错流超滤技术 /
- 海洋胶体 /
- 铀、钍同位素 /
- 镭同位素 /
- 有机碳
Abstract: A ctnss-flow ultrafiltration system,including a prefilter (0.22 μm),a Masterflex pump and a polysulfone hollow fiber 10 KDa ultrafiltration membrane (Amicon H10P10-20),is evaluated for its feasibility in sampling colloidal uranium,thorium,radium isotopes and organic carbon (0C) in seawater.The retention characteristics and sorptive potential of the 10 KDa ultrafilter are examined through laboratory experiments using a 40 KDa fluoresceintagged dextran and standard ²³⁴Th as tracers.The mass balance of ²³⁴U,²³⁸U,²³⁴Th,²²⁴Ra,²²⁶Ra and OC during ultrafiltration is also evaluated.The results show that the 10 KDa ultrafiltration membrane can indeed tetain the 40 KDa dextran with a retention coficient of 0.85.However,sorptive loss of the 40 KDa dextran to the system is 18%.Mass balance of uranium,thorium,radium isotopes and OC are excellent,with recoveries ranging from 95% to 98%,indicating that losses or contamination problems during ultrafiltration are minimal.The concentration of ²³⁴Th in the permeate,when plotted as a function of concentration factor,is found to fit an ultrafiltration permeation model.Percentage of colloids in the dissolved phase decreases as follows:thorium isotopes,organic carbon,radium isotopes about equaling uranium isotopes,which is consistent with their geochemical properties,i.e.,thorium is a particle-reactive nuclide while uranium and radium are more soluble in seawater.
- Cross-flow ultrafiltration /
- marine colloids /
- thorium isotopes /
- urariium isotopes /
- radium isotopes

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参考文献(19)

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