Effect of temperature on the efficiency of inorganic phosphate used as antiscaling inhibitors

Scaling is a very widespread and inevitable problem in systems and equipments supplied with natural waters. scale deposits are compact and adherent to the walls of water distribution piping and industrial or domestic installations causing several technical and economical problems. hamma drillings represent an important water resource which feed most of the constantine city with drinking water and also used for factory constructions and agronomic implantation. nevertheless,this water is a scale forming water because of its high hardness (59°f). the present investigation is a contribution to fight against this scaling phenomenon by inhibition process using mineral phosphates (kh2po4 and polyphosphates). scaling tests were performed using the chronoamperometric method. it was shown that the scaling power increases with temperature and decreases with the addition of low concentrations of tested inhibitors. it was also concluded that the used polyphosphate is more efficient than kh2po4. the electrode scaling is blocked for more than 30min at 30°c in presence of 2mg/l of monophosphate and only 0.5mg/l of polyphosphate. for high temperature (50°c),these two inhibitors seem also to be effective with 3 and 2mg/l for monophosphate and polyphosphate,respectively. so,scaling phenomenon generated by hamma water can be prevented using phosphate inhibitors.