ETUDE DU POUVOIR ADSORBANT DU CHARBON ACTIF EN POUDRE POUR L’ELIMINATION DES PHOSPHATES DES EAUX NATURELLES

Abstract

The aim of this study is to test the efficiency of removal of phosphate in natural waters by adsorption on powdered activated carbon (PAC). The treated solutions are synthetic phosphate solutions in distilled water and ground waters in the region of Biskra. Phosphate adsorption tests have shown that the retention of phosphate on the PAC is a reversible phenomenon. The equilibrium time is less in mineralized water (30 seconds) then in distilled water (3 hours). Removal rate are improved with the increase of the dose of the adsorbent (0,1 to 4 g/l). Adsorption of phosphate follows the two models of Langmuir and Freundlich. The process is influenced by the pH of treatment. In synthetic solutions of distilled water, removal rate decrease with the increase of the initial phosphate content (1 to 20 mg/l) in contrast in synthetic solutions of mineralized water the opposite occurs. This is a result of unlike the removal mechanisms of phosphate in the two media of different mineralization