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I N THIS study Acrylic acid/ Carboxymethylcellulose/Titanium dioxide (AAc/CMC-TiO 2) hydrogel nanocomposite was synthesized by free-radical crosslinking copolymerization via gamma irradiation. It was characterized using FT-IR and swelling properties. The swelling percentage increases with increasing time until reaches a certain limiting value after 6h. The synthesized nanocomposite was used as an adsorbent for remediation of Cd(II), Zn(II) and Pb(II) from aqueous solutions by the static adsorption technique. It was found that the optimum pH for the adsorption is 5 and the sorption process is carried out at fast operating time, 30-40 min, for all investigated metal ions. It was also found that the metal ions sorption capacity decreases with increasing the dosage of AAc/CMC-TiO 2 from 5 to 150 mg. A progressive increase in the metal ions sorption capacity was obtained with increasing the initial metal ion concentration from 0.01 to 0.05 mol L-1 and the saturation of the sorbent active sites was done at initial metal ions concentration at 0.1 mol L-1. No significant interference on the removal of Pb (II) in the presence of NaCl, Na-acetate, KCl, KNO 3 and NH 4 Cl ions while a slight decrease in removal of Cd (II)and Zn(II) was done. The pseudo-second order kinetic model and Freundlich adsorption model describe well the kinetic and isotherm, respectively, of the adsorption process of the investigated ions.

Nano magnesium aluminum layered double hydroxide (nano MgAl LDH) sorbent, prepared via autocombustion route, was used as a base material for chromatographic 99 Mo/ 99m Tc column generator. The acid-base titration curve proved the amphoteric nature of the prepared MgAl LDH (with a point of zero charge at pH 6.5). The sorbent, prepared at the optimum conditions, was characterized by IR spectroscopy and XRD. The Mo(VI) breakthrough capacity was found to be 6.5410 -2 mmol Mo(VI)/g, i.e., 6.27 mg Mo(VI)/g. The prepared 99 Mo/ 99m Tc chromatographic column generator showed a good performance. The 99m Tc elution yield was found to be 75.0 % at flow rate of 1 ml/min, pH of the eluate ranged from 5.5 to7.5, the radionuclidic purity of the eluted 99m Tc was > 99.99 % and Al 3+ content in the eluate was < 5 ppm. The peaks that appeared in the XRD pattern resembled those in the XRD pattern of MgAl LDH, Mg6Al2(OH)16 2+ , and α-Al2O3 phases. The FT-IR spectrum showed the band at 681 cm -1 which may be attributed to the translational mode of the Al-OH bond being characteristic of LDH's. In conclusion Nano magnesium aluminum layered double hydroxide (MgAl LDH) sorbent was well synthesized and characterized and used as a base material for 99 Mo/ 99m Tc column generator achieving higher loading capacities than that of alumina.