Surface charge property governing co-transport of illite colloids and Eu(Ⅲ) in saturated porous media  

作　　者：Xiaoyan Wei Duoqiang Pan Qi Tan Xinyi Shi Junjun Hou Qingfeng Tang Zhen Xu Wangsuo Wu Bin Ma 

机构地区：[1]Frontiers Science Center for Rare Isotopes,Lanzhou University,Lanzhou 730000,China [2]Laboratory for Waste Management,Paul Scherrer Institut(PSI),CH-5232 Villigen PSI,Switzerland [3]School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China

出　　处：《Chinese Chemical Letters》2023年第11期248-254,共7页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.22176077,22006060);the Fundamental Research Funds for the Central Universities(No.lzujbky-2022-sp04);Science and Technology Program of Gansu Province,China(No.20JR10RA615).

摘　　要：The transport of colloids and radionuclides is sophisticated because of the variety of charge properties between colloidal particles and host subsurface media, which causes great difficulty in establishing a reliable model of radionuclides migration by taking the colloid phase into consideration. In this work,the co-transport of illite colloids(IC) and Eu(Ⅲ) in the quartz sand and iron-coated sand porous media was investigated by column experiments to address the predominant mechanism of charge properties on co-transport. Results showed that Eu(Ⅲ) transport was driven by the illite colloids and electrostatic interaction was critical in governing the co-transport patterns. The promotion of Eu(Ⅲ) transport by IC was attenuated in the iron-coated sand systems;more IC-Eu(Ⅲ) complexes were retained uniformly in the column. The pore throat shrinkage caused by electrostatic attachment between aggregated IC and iron oxides exacerbated the physical straining and size exclusion effect of IC-Eu(Ⅲ) complexes. An aggravated irreversible retention of IC-Eu(Ⅲ) was detected in iron-coated sand column due to the electrostatic attraction of IC-Eu(Ⅲ) to host media. The findings are essential for improving the understanding on the potential transport, retention and release risk of colloids associated radionuclides, and imply that the positively charged permeable reactive barrier is an effective strategy to reduce the transport risk of colloid associated radionuclides.

关 键 词：Illite colloids Eu(Ⅲ) Co-transport Release Charge property 

分 类 号：O61[理学—无机化学]