Uranium(VI) recovery from its leach liquor using zirconium molybdophosphate composite: kinetic, equilibrium and thermodynamic studies

Humic acid attachment on chitosan-modified silica gel as an economical, efficient, and selective adsorbent for thorium and uranium removal

A novel, low-cost adsorbent material was prepared by the immobilization of humic acid on a silica gel surface coated with cross-linked chitosan (SiChiHA). The adsorbent was developed to remove selectively of Th(IV) and U(VI) from aqueous solution, including their pre-concentration and separation from lanthanides and high salinity conditions. A simple waste-less humic acid immobilization method was shown to be successful based on FT-IR, SEM-EDS, and zeta potential characterization results. The adsorbent was found to be stable over a wide pH range, with the highest capacities obtained at pH 3.5 (Th(IV)) and pH 5 (U(VI)). Langmuir model calculations yielded a maximum capacity of 30.6 mg g^-1 and 75.4 mg g^-1 for Th(IV) and U(VI). The adsorption process was found to be rapid (half concentration was removed within 10 min) and best described by a pseudo-second order rate equation. Increasing NaCl concentration up to 2 mol L^-1 or lanthanide concentration up to 100 times did not significantly affect the removal efficiency for either Th(IV) of U(VI). Both elements could be sequentially separated by elution with ammonium citrate and nitric acid, respectively. The adsorption-desorption experiment showed that the adsorbent could be used for at least five cycles without significant capacity loss. This study provides insight into the development of low-cost adsorbent with practical functionality, including separation and regeneration ability, the advantageous properties scarcely reported in low-cost adsorbent literature.

The influence of cobalt manganese ferrite nanoparticles (Co0.5Mn0.5Fe2O4) on reduction of hazardous effects of vanadate in adult rats

Effect of cobalt manganese ferrite nanoparticles (M-NPs) (Co0.5Mn0.5Fe2O4) on vanadium hazards was assessment in the present study. Four groups of adult male albino rats [control group and three variably treated groups with ammonium metavanadate accompanied with or without cobalt M-NPs] were studied. The oral administration of ammonium metavanadate (Am.V) (20 mg/kg b.wt.) demonstrated the facility of vanadium to distribute and accumulate in the distinctive body organs and ordered as kidney > liver > lung > brain > spleen. Also, Am.V administration induce a significant disturbance in many physiological parameters (RBS, cholesterol, triglyceride, aspartate transaminase, alanine transaminase, Alb., bilirubin, Alk.Ph., urea, creat., Hb%, red blood cell count and packed cell volume) which might be expected to the liberation of free radicals according to the vanadium intoxication or its ability to disturb many body metabolisms. On the other hand, the intraperitoneal administration of 5% M-NPs in parallel with Am.V orally administration showed the ability of M-NPs to reduce Am.V dangerous impacts, which might be resulted from the essentiality of M-NPs metals to the body metabolism and to its free radicals scavenging properties. So, M-NPs could reduce Am.V hazardous effects.