Authors:Omar Abderrahim, Nacer Ferrah, Mohamed Didi, and Didier Villemin
A new chelating polymeric sorbent has been developed using polystyrene resin grafted with phosphonic acid. After characterization
by FTIR and elementary analysis, the new resin has been investigated in liquid–solid extraction of europium(III). The results
indicated that phosphonic resin could adsorb Eu(III) ion effectively from aqueous solution. The adsorption was strongly dependent
on pH of the medium with enhanced adsorption as the pH value of 6.5. The influence of other analytical parameters including
contact time, amount of resin, metal ion concentration, and ionic strength were investigated. The maximum uptake capacity
of Eu(III) ions was 122.6 mg/g grafted resin at ambient temperature, at an initial pH value of 6.50. The overall adsorption
process was best described by pseudo first-order kinetic. When Freundlich and Langmuir isotherms were tested, the latter had
a better fit with the experimental data. Furthermore, Eu(III) could be eluted by using 1.0 mol/L H2SO4 solution and the grafted resin could be regenerated and reused.
Authors:Nacer Ferrah, Omar Abderrahim, Mohamed Didi, and Didier Villemin
A novel sorbent resin consisting of a Phosphonic Acid grafted on Merrifield Resin (PA-MR) for the extraction of uranyl from
nitrate media is described. The sorption behaviour of uranyl cation on PA-MR was investigated using batch equilibrium technique.
The effects of parameters such as shaking speed, pH levels, contact time, metal concentrations, ionic strength and temperature
were reported. The results show that the sorption capacity increases with increasing both initial uranyl ion concentration
and temperature and decreases with increasing ionic strength. Therefore, the optimum condition for the present study should
be using 6.6 mg adsorbent per 1.0 mg uranyl in solution with pH 3.6 and shaking at 250 rpm for 180 min. The adsorption behavior
of the system was also investigated and found to be in line with Langmuir isotherm. The kinetic data was well described by
the pseudo second-order. Thermodynamics data leads to endothermic process ∆H = + 31.03 kJ−1 mol−1, ∆S = + 146.64 J mol−1 K−1 and ∆G = −11.96 kJ mol−1 at 20 K. ∆G decreased to negatives values with increasing temperature indicating that the process was more favoured at high temperature.