chlorination on surface passivation of CUNI70/30 condenser tubes Cristiani Pierangela*, Giorgio Perboni** EUROCORR 2009 The European Corrosion Congress Nice, France, 6-10 Settembre 2009 * ERSE SpA ** CESI SpA The monitoring of corrosion behavior of CuNi 70/30 condenser tubes in sea water, performed in several industrial cooling systems, shows that the passivation of this alloy is strongly affected by the presence of biologically active slime. The results obtained confirm the relevant role played by biofouling deposition against the formation of protective oxide layers on the exposed surfaces of the copper alloy to seawater and the positive influence exercised by chlorination treatments based on short, intermittent and low level dosages. In the present paper, the innovative specific integrated equipment specifically set for industrial application and suitable to monitor electrochemically the corrosion (by Linear Polarization Resistance technique), the biofilm growth (by the BIOX electrochemical probe), the chlorination treatment (by electrochemical and colorimetric methods) and other physical-chemical parameters of the water is described in detail and commented.