Table 6: Iron oxide minerals detected by XRD.

Pipe Solution Inner face Outer face 1 Static tap water Fe(OH)3 Fe3+O(OH) Aerated tap water Fe3+O(OH), Ca(CO3) Fe3+O(OH) Aerated solution of 3.5% NaCl FeO(OH) FeOOH 2 Static tap water Fe3O4, FeO(OH), CaO Fe3+O(OH) Aerated tap water Fe3+O(OH), Ca(CO3) Fe3+O(OH) Ca(CO3) Aerated solution of 3.5% NaCl FeO, Fe3+O(OH), Ca3Fe15O25 Fe(OH)3 3 Static tap water Fe3+O(OH), FeOOH Fe3+O(OH) Aerated tap water FeOOH, FeCl2 Fe3+O(OH) Aerated solution of 3.5% NaCl Fe3+O(OH), FeCl3 Fe3+O(OH)