Microbial treatment feasibility in drinking water treatment plants

In this study hundred water samples were collected from River Nile in Rod El-Farag region, Cairo, Egypt to make isolation and identification of some bacterial strains that have the ability to tolerate high conc. of Al, Fe and Mn metals up to 5 mg/l. The isolated bacterial strains were Pseudomonas putida biotype A, Citrobacter freundii and Aeromonas hydrophila DNA Group1.The first and second strains had the ability to tolerate up to 5 mg/l Fe, Mn and Al separately; while the last one had the ability to tolerate up to 5 mg/l Al only. The strains were identified by biochemical tests and by Biolog GEN III Microplate technique. The Nile water samples were supplemented with 2 mg/l of Fe, 2 mg/l of Mn and 2 mg/l Al metal ions together in their salt form FeCl3.6 (H2O), MnSO4.H2O and AlKO8S2.12 (H2O) respectively as a spike sample, the pH became 7.2. The conc. of Fe, Mn and Al of raw water was measured before and after the addition. The amount of dead bacterial biomass added was (15 mg / 150 ml), the shaking speed was 160 rpm and the temperature was 28 oC while, contact time was a variable factor. Pseudomonas putida dead biomass had the ability to biosorb Fe, Mn and Al metals form water.