The Water distribution of the town of Constantine resulting from the water Hamma resources is supersaturated with calcium carbonate, salt not very soluble and is the predominant component of scales deposited from natural water. This water has a hardness of 59 °F. During their movement, these waters give rise to the phenomenon of scaling which lead to economical problems because of the low thermal conductivity of the solid layer. This decreases the operating efficiency in heat transfer exchangers and can even cause serious failures of industrial facility. Also, the increase of this layer involves decrease of flow and can cause the seizing of the valves and taps. In this work we studied the effect of the temperature and concentration of two scale inhibitors K2HPO 4 and K3PO 4 to reduce the scaling power for Hamma hard water. Calcium carbonate was deposited by electrochemical reduction of oxygen at negative potential (-1 V) and studied on metal electrode by chronoamperometry technique. The study of the curve of chronoamperometry showed that, for the water of Hamma, the time of scaling is 13.7 minutes at 30 °C. Furthermore, the increase of temperature decreases the value of time of scaling. The addition of 3 mg/L of K2HPO4 and 2.5 mg/L of K3PO4,the resulting curve becomes a right and prevent of scaling.
