摘要
The physico-chemical and biological （algal and bacterial） quality of tap water in Tanta City were elucidated. Samples were collected during December 2011, covering all the water plants and the areal extension of the pipe line network in Tanta. Total dissolved solids content classifies water origin into surface water, shallow and deep groundwater. Fe, Mn and hardness in some samples of groundwater origin are obviously exceeding the WHO （World Health Organization） limit. Mostly, green algae are found （31 species）, followed by diatoms （19 species）, then blue-green algae （13 species）. CCA （Canonical Corresponding Analysis） indicates that green algae are strongly correlated with pH, NH4, alkalinity, Mn and Si; diatoms with EC （electric conductivity）, turbidity, Zn and Si and blue green algae with EC and alkalinity. 50% of samples of surface origin, 80% of samples of both deep and shallow groundwater origins crossed WHO and Egyptian guideline in their content of mean TCC （Total Coliform Count）. CCA estimates strong correlations of TCC with temperature, NH4 and PO4; E. coli with EC; heterotrophic bacteria with turbidity and NO3; Salmonella sp. with Si and SO4 and Pseudomonas aeruginosa with Mn. Finally, the water plants treatment may be not effective and pipes serve as a reservoir for pathogenic microorganisms.
