Characterization of Corrosive Bacterial Consortia Isolated from Water in a Cooling Tower

Table 4

Polarization and impedance parameters for copper in the presence/absence of bacterial isolates and biocide.

Systems	Polarization			Impedance data
	𝐸corr (mV)	𝑖corr (A/cm^2)	Corrosion rate (mm/y)	𝑅𝑠  Ω	𝑅ct  Ω	𝑅𝑝  Ω
System 1	−255	3.9×10^−9	4.5×10^−5	100	12.7	2×10^6
System 2	−225	5.5×10^−7	6.5×10^−3	148	0.01	1.4×10^3
System 3	−275	1×10^−9	1.1×10^−5	181	163	1.8×10^7

System 1: 250 mL sterilized cooling tower water with 1% of supplemented WNM medium. System 2: System 1 with 1 mL of M. timonae bacterial culture (about 10⁵ CFU/mL). System 3: Systems 1 and 2 with the addition of 5 ppm biocide (2-bromo-2-nitropropane-1, 3-diol) (bronopol).