Adsorption treatment residues as novel ecological corrosion inhibitors applied to mild steel in a molar hydrochloric acid medium: Experimental studies and surface characterization

Abstract

An experimental investigation into the corrosion inhibition properties of spent coffee grounds (I), activated carbon (CAP) elaborated from spent coffee grounds and two additional residues (CAPBM) and (CAPRhB) derived from methylene blue and rhodamine B dyed wastewater treatment by adsorption on CAP was conducted in 1 M HCl acid medium on mild steel (MS). Experimental methods (polarization curves and electrochemical impedance spectroscopy (EIS)) as mild steel (MS) corrosion inhibitors in a molar hydrochloric acid solution. Then, they were studied by Fourier transform infrared spectroscopy (FTIR). Furthermore, the adsorption process is confirmed by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and UV–visible analyses have been carried. The impedance and inhibition efficiency parameters are found to grow with the concentration of the inhibitors. Hence, it is significant that the maximum inhibition efficiencies are around 90%, 89%, 88%, and 78% for CAPBM, CAPRhB, I, and CAP respectively for the optimum concentration of 1 g/L.