Adsorption and desorption of uranium on nano goethite and nano alumina

Abstract

The nano goethite and nano alumina were synthesized to investigate the effect of nanoscale size on adsorption-desorption of U(VI) from aqueous solution. It was determined that the site densities of nanoparticles are higher than a-alumina and goethite, whereas slight effect of carbonate on adsorption of U(VI) onto nanoparticles was observed. The maximum adsorption capacities of nano alumina and nano goethite were *151 and 79 mg/g, respectively. The batch desorption indicated stronger binding affinity of U(VI) for nanoparticles as compared to non-nanoparticles, which were consistent with the results of surface complexation modeling assuming weak and strong sites for nanoparticles while weak sites for a-alumina and goethite.

Kinetics of Uranyl Peroxide Nanocluster (U60) Sorption to Goethite

“…The behavior of U 60 at the goethite-water interface is similar to that of discrete U(VI) but is governed by different sorption mechanisms and reaction kinetics. While U(VI) forms inner-sphere complexes with goethite 21,40 and is characterized by fast sorption kinetics (i.e., minutes-hours), 41,42 we hypothesize that U 60 behavior is dominated by outer-sphere interactions due to the unreactive '-yl' oxygens and full coordination in the equatorial plane or perhaps a K + -bridged ternary complex and demonstrate that steady-state is achieved within a longer time frame (i.e., days). These different sorption mechanisms are also manifested in different desorption behaviors.…”

Removal of uranium(VI) from aqueous solution using nanoscale zero-valent iron supported on activated charcoal

“…and UO 2 (OH) 2 [16], the presence of these complexes would inhibit the adsorption, reduction and precipitation of uranium(VI). Therefore, it was not favorable for the removal of uranium(VI) under higher or lower pH, when pH was 5-6, the removal effect was higher than the one of nZVI that Yuan [17] reported.…”

Study on adsorption characteristics of uranyl ions from aqueous solutions using zirconium hydroxide

“…4 The proposed schematic diagram of adsorption mechanism of uranyl ion by ZH Table 1 Comparison of the q max for different adsorbents Adsorbents Conditions q max (mg g -1 ) Reference Zeolite Ph 6.0 T = 293 K 11.1 [11] Humic acid-immobilized zirconium-pillared clay pH 6.0 T = 303 K 132.7 [13] Natural diatomite pH 5 T = 294 K 6.1 [38] Fe 3 O 4 @SiO 2 pH 6.0 T = 298 K 52 [39] TiO 2 pH 4.5 T = 318 K 36.1 [40] Geothite pH 5.0 T = 298 K 28.2 [41] Nano alumina pH 5.0 T = 298 K 151.5 [41] Graphene oxide/polypyrrole pH 5.0 T = 298 K 147.1 [42] Amidoxime modified Fe 3 O 4 @SiO 2 pH 5.0 T = 298 K 105 [43] Cyclodextrin-modified graphene oxide nanosheets pH 5.0 T = 288 K 97.3 [44] Functionalized graphene oxide pH 4.0 T = 293 K 138.9 [45] Fe/Fe 3 C@porous carbon sheets pH 4 T = 298 K About 2300 [46] Poly(amidoxime)-reduced graphene oxide pH 4.0 T = 293 K 872 [47] ZH pH 5.0 T = 303 K 451.7 This work J Radioanal Nucl Chem illustrate the proposed adsorption mechanism. In Fig.…”