In this study an abundant and a low cost natural occurring bentonite (nbentonite) and activated bentonite has been considered for the removal of cesium, cobalt, lead and cupper from liquid wastes. Nabentonite, Kbentonit e was prepared by treated with 5 % NaOH and 5% KOH for 6 hours at 70 o C while Tbentonite was heated up to 850 o C for 30 min. The chemical composition of nbentonite and activated bentonite obtained by using XRF equipment. The study has been carried out batchwise and the influence of physicochemical key parameters such as the contact time, the temperature, the adsorbate concentration, the adsorbent dosage, the solution pH has been considered. The maximum metal ions uptake were obtained at 60 min. contact time and pH 3 for Pb(II) and Cu(II) , pH 2.5 for Co(II) and Cs(I). The maximum metal ion uptake value for Pb(II), Cu(II), Co(II) and Cs(I) by using nbentonite were 85.2, 83 .4, 81.1 and 80.5 wt.% respectively, while the maximum uptake for the same metal ions by using Nabentonite were 98.7, 96, 93.5 and 90.2 wt. % respectively. It was found that the percent removal of the metals ion studied were seriated in the following order: Nabe ntonite > Kbentonite > Tbentonite > nbentonite. The Langmuir kinetic model was employe d and well represented the experimental data.

Fixation of cesium, cobalt, lead and cupper onto different cationic forms of a natural zeolite: activated bentonite

The aim of this work is to establish the optimum conditions for the removal of some radioactive elements from their waste solutions. In this respect an exploratory investigation is carried out using the clay minerals (kaolinite and vermiculite) to test the feasibility of its using for decontamination purposes and volume reduction. The different parameters affecting the sorption capacity of the radioactive elements of Cs-134, Co-60 and Eu-(152+154) by the investigated clay minerals have been studied. The uptake of the metal ion was determined for clay mineral-cation solution system as a function of contact time, pH, metal ion concentration and presence of some competing cations. Sorption data have been interpreted in term of Freundlich equation. The presence of some organic complexing agents also affect the sorption process. The desorption of the investigated metal ions was also studied using different desorption solutions. The obtained data show that the clay mineral vermiculite can be considered as an efficient sorbent for metal cations from their aqueous solutions since the uptake efficiency is more than 90% for the three elements studied.

H. Molukhia

Papers

Treatment of Radioactive Waste Solutions Using Local Clay Minerals