Effective and rapid adsorption of uranium via synergy of complexation and cation-π interaction

Author(s):  
Yan Wang ◽  
Xiaolin Liu ◽  
Yingrong Xie ◽  
Bowei Chen ◽  
Yong Zhang
Keyword(s):  
2021 ◽  
Vol 9 (5) ◽  
pp. 106242
Author(s):  
Rong Zhang ◽  
Yu Fan ◽  
Lijun Wang ◽  
Jie Li ◽  
Hui Li ◽  
...  

Isobars for the adsorption of O 2 , H 2 and CO on evaporated films of Rh, Mo, W and Fe, of Ch and CO on Ta, Pt and Pd, and of O 2 on Cu, Al and Zn have been obtained. On Rh, Mo and W the rapid adsorption of O 2 and H 2 at -183° C results in formation of monolayers with one atom per surface atom. On Ta, Pt, Pd, Cu, Al and Zn oxygen, and on Fe hydrogen form similar monolayers, but on Fe oxygen forms several layers of oxide. On Rh, Mo and possibly Ta the fast CO chemisorption corresponds to a two-site mechanism; on W and Fe it lies between that for a single and a two-site mechanism; on Pt and Pd single-site adsorption may take place. Kinetics of slow oxygen uptakes have been followed on Rh, Mo, W, Ta, Fe, Cu and Zn. With Rh, Mo, W, Ta and Zn it is believed that formation of the first oxide layer has been observed, and the rate expression is velocity ∝√{ p ) e -∝ v / RT , where v is the adsorbed volume and ∝ is a constant. The suggested mechanism is interchange of adsorbed oxygen atoms with underlying metal atoms, whereby metal atoms are exposed for further oxygen adsorption. On Cu and Fe formation of up to six and ten oxide layers respectively have been observed, and the rate expressions (u ∝ p 0.75 / v 2 and u ∝ p 0.2 e ∝'/ v ) have been interpreted in terms of the theory of Cabrera & Mott (1948).


Author(s):  
Lin Ren ◽  
Xudong Zhao ◽  
Baosheng Liu ◽  
Hongliang Huang

Abstract Rapid removal of radioactive strontium from nuclear wastewater is of great significance for environment safety and human health. This work reported the effective adsorption of strontium ion in a stable dual-group metal-organic framework, Zr6(OH)14(BDC-(COOH)2)4(SO4)0.75 (Zr-BDC-COOH-SO4), which contains strontium-chelating groups (-COOH and SO4) and strongly ionizable group (-COOH). Zr-BDC-COOH-SO4 exhibits very rapid adsorption kinetics (<5 min) and a maximum adsorption capacity of 67.5 mg g−1. The adsorption behaviors can be well evaluated by pseudo-second-order model and Langmuir isotherm model. Further investigations indicate that the adsorption of Sr2+ in Zr-BDC-COOH-SO4 would not be interfered by solution pH and adsorption temperature obviously. Feasible regeneration of the adsorbent was also demonstrated through a simple elution method. Mechanism investigation suggests that free -COOH contributes to the rapid adsorption based on electrostatic interaction while introduction of -SO4 can enhance the adsorption capacity largely. Thus, these results suggest that Zr-BDC-COOH-SO4 might be a potential candidate for Sr2+ removal and introducing dual groups is an effective strategy for designing high-efficiency adsorbents.


2017 ◽  
Vol 70 (17) ◽  
pp. 2940-2949 ◽  
Author(s):  
Hadi Naslhajian ◽  
Mojtaba Amini ◽  
S. Morteza F. Farnia ◽  
Ayda Sheykhi ◽  
Onur Şahin ◽  
...  

2018 ◽  
Vol 255 ◽  
pp. 160-167 ◽  
Author(s):  
Xiufang He ◽  
Zhansheng Wu ◽  
Zhonghai Sun ◽  
Xinhui Wei ◽  
Zhilin Wu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document