No abstract

No abstract

No abstract

The aim of this work is to study the zinc removal possibility by adsorption on a bentonite of Mostaganem (Algeria) and kaolin, and determine various reaction parameter effects on the process. Experiments were carried out with synthetic distilled water solutions. The kinetics of adsorption results showed that zinc removal is max with 89.8 ℅ efficiency for bentonite after 20 min and 45.48℅ efficiency for kaolin after 60 min of contact time. Increasing in adsorbent dose (0.5 to 8 g/l) improves zinc removal efficiency for 5mg/l like an initial concentration. Zinc removal efficiency by the two adsorbent decreases with the initial zinc concentration increasing (2 to 20 mg/l). pH of treatment considerably affects the zinc retention rate. Zn removal efficiencies are noticeable at basic pH. Whatever reaction parameter tested, it seems that bentonite is more effective than kaolin.

Calcium treated bentonite clay (CTBC) was prepared by CaCl 2 impregnation of Algerian bentonite clay. The prepared adsorbent was characterized and successfully used to remove Cu (II) ions from aqueous solutions at different conditions (pH, stirring time and initial copper concentration). Results showed that the raw bentonite was changed completely into Ca-bentonite, which exhibits a high adsorption capacity (qt=19.98 mg g −1 ) at pH=5.0. It appeared that the sorption mechanisms are simultaneous and strongly depend on pH value. In the pH range from 3-10, the removal of copper occurs mainly by ion exchange, surface metal complexation and precipitation of Cu (OH) 2 . It was also found that the experimental data of kinetic adsorption are well fitted by the pseudo-first order model. Equilibrium data obeyed the Langmuir isotherm with maximum adsorption capacity of 55.48 mg g −1 .The mean adsorption energy predicted by Dubinin-Radushkevich model (E=1.55 Kj/mol) shows the physical nature of the adsorption interactions. Results of this study suggest the potential of the prepared CTBC which can be used easily for fast decontamination of wastewater containing toxic metal ions.