IRON RELEASE FROM CORRODED IRON PIPES IN DRINKING WATER DISTRIBUTION SYSTEMS: EFFECT OF DISSOLVED OXYGEN

Study of the effect of dissolved oxygen on iron release from old corroded iron pipes in drinking water distribution. Corrosion scales from 70-years-old galvanised iron pipes were characterized as porous deposits of Fe (III). The iron release studies confirmed that iron was released from corroded pipes primaly in the ferrous form. It was found that increasing the dissolved oxygen concentration in water reduced amount of iron release during stagnation. The dissolution of corrosion scales is an important method of iron release from corroded metal pipes. Both the composition and structure of the corrosion scales can influence the amount of iron released to the solution.