Preparation of Two Novel Stable Silica-Based Adsorbents for Selective Separation of Sr from Concentrated Nitric Acid Solution
Chang Liu,
Shichang Zhang,
Xinpeng Wang,
Lifeng Chen,
Xiangbiao Yin,
Mohammed F. Hamza,
Yuezhou Wei,
Shunyan Ning
Affiliations
Chang Liu
State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures, MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
Shichang Zhang
School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026, China
Xinpeng Wang
State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures, MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
Lifeng Chen
School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, China
Xiangbiao Yin
School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, China
Mohammed F. Hamza
School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, China
Yuezhou Wei
School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, China
Shunyan Ning
School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang 421001, China
Crown ethers are famous for the highly selectively grab Sr(II) from concentrated nitric acid solution due to the size match, but they suffer from the high leakage into the liquid phase caused by the presence of a large number of hydrophilic groups. To reduce their leakage, two novel porous silica-based adsorbents, (DtBuCH18C6 + Dodec)/SiAaC-g-ABSA and (DtBuCH18C6 + Dodec)/SiAaC-g-3-ABSA, were prepared by vacuum impregnation with organic contents of about 55.9 wt.% and 56.1 wt.%, respectively. The two adsorbents have good reusability and structural stability, and the total organic carbon leakage rates in 2 M HNO3 solution are lower than 0.56 wt.% and 0.29 wt.%, respectively. Batch adsorption experiments revealed that the two adsorbents possessed good adsorption selectivity towards Sr, with SFSr/M over 40, except that of SFSr/Ba in 2 M HNO3 solution. The adsorption equilibrium of Sr in 2 M HNO3 solution was reached within 1 h, with saturated adsorption capacities of 36.9 mg/g and 37.5 mg/g, respectively. Furthermore, the XPS results indicate that the adsorption mechanism is the coordination of the crown ether ring with Sr. This work not only develops two novel adsorbents for the separation of Sr in nitric acid environments; it also provides a method for effectively reducing the water solubility of crown ethers.
