FILTRES A SABLE IMMERGE A ALIMENTATION INTERMITTENTE: EFFET DE LA HAUTEUR DE SABLE SUR L'ELIMINATION DES PARAMETRES PHYSICO-CHIMIQUES [ BIOSAND FILTER: IMPACT OF SAND DEPTH IN PHYSICO-CHEMICALS PARAMETERS REMOVAL ]

Four biosand filters were used for treatment of Banco river source water, to investigate the effects of sand depth (30, 50, 70 and 90 cm) on the removal of suspended solids, nitrogen and oxidized forms of the chemical demand oxygen and their effect on the pH. The results showed that the filter of 90 cm of sand was the most efficient. However, the purification yields between filters 50, 70 and 90 cm of sand showed no significant difference, and the treated water met the drinking water standards of the world health organization. Therefore, sand depth between 50 and 90 cm can be used in biosand filter to treat water.