Inhibition Effect of Exopolysaccharide ofVibrio Neocaledonicus sp. on Q235 Carbon Steel in Sulphuric Acid Solution

The inhibition effect of exopolysaccharide (EPS) extracted from Vibrio neocaledonicus sp. on carbon steel Q235 has been studied by means of potentiodynamic polarization, electrochemi- cal impedance spectroscopy (EIS) and scanning electronic microscopy (SEM). The results showed that EPS could inhibit effectively the corrosion for Q235 steel in solution of 0.5 mol/L H2SO4 be- cause of that a film of Fe-EPS could formed on carbon steel during the corrosion process. The inhi- bition efficiency reached the maximum when the concentration of EPS was 1.0 g/L. The absorption of EPS on Q235 steel was chemisorption and obeyed the Langmuir adsorption isotherm. The com- position of EPS was identified by using FTIR.