Citrobacter Freundii on Corrosion Behavior of HSn701-A in Reclaimed Water

A strain of Citrobacter freundii with sulfate-reducing function was isolated from the sticky mud at the bottom of cooling tower in a power plant. Scanning electron microscopy (SEM) was applicated to observe the cell morphology in recycled water and the medium; the sizes of cells found in reclaimed water were slightly larger than in the medium. Growth curves showed that generation of the strain were separately 3.01h and 4.39h, which means the recycled water was more suitable than the test medium for bacteria´s growth. In orthogonal experiment, the order of main factors´ influence on corrosion of HSn701-A in reclaimed water were pH>C_Cl-/C_SO42->NH₄⁺-N>COD. Results of Electrochemical impedance spectroscopy (EIS) showed that Citrobacter freundii on HSn701-A of the corrosion was closely related to the formation of microbial membranes and corrosion products membranes on the surface of alloy.