Olive mill wastewater (OMW) as corrosion inhibitor for copper in NaCl solution

Omw is greatly enriched in hydroxytyrosol (ht) and slightly in tyrosol. this compound acts as mixed-type corrosion inhibitor for copper in 3 % nacl solution. the molecules of this inhibitor physically adsorbed onto both anodic and cathodic sites of the copper surface. adsorption of this inhibitor on the copper surface obeys the langmuir adsorption isotherm. the free energy of adsorption (-30.50kj mol-1) reveals a strong physical adsorption of the ht on the metal surface. the exceptional effect of this inhibitor is above ecorr. the passivation range greatly increases upon addition of inhibitor and increases further with increasing ht concentration.