Phosphites compound: Novel corrosion inhibitor for radioactive waste container (carbon steel) in simulated Callovo-Oxfordian (COx) groundwater

Abstract NaNi(H 2 PO 3 ) 3 ·H 2 O (NaNiPh) has been evaluated as a new inorganic inhibitor for radioactive waste container (carbon steel) corrosion in the Callovo-Oxfordian (COx) groundwater using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The experimental findings were supported using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) investigations. The value of the inhibition efficiency obtained from polarization curves is 96.7% at 100 ppm concentration, which is in good agreement with the data obtained from EIS (93.7%). Based on polarization data, NaNiPh can be classified as mixed inhibitor. The corrosion process is inhibited by physical adsorption of NaNiPh on carbon steel surface and the adsorption process follows Langmuir isotherm model. The activation parameters were calculated and corroborate the proposed inhibition mechanism.