traitement de l'eau (1) qualité de l'eau (1) turbidité (1) eau de surface (1) sable (1) élimination (1) ménage (1) eaux souterraines (1) gravier (1) débit (1) filtre (1) eau potable (1) Afrique (1) Afrique (1) Shigella (1) Rates (1) Salmonella typhimurium (1) Zeolites (1) Water quality (1) Groundwater (1) Water--Purification (1) Water (1) Vibrio cholerae (1) Turbidity (1) Sewage--Purification (1) Sand (1) Performance (1) Percentage (1) Pathogenic microorganisms (1) Materials (1)