Synergistic Effect of Carbamide and Sulfate Reducing Bacteria on Corrosion Behavior of Carbon Steel in Soil

Abstract

Synergistic effect of carbamide and sulfate reducing bacteria (SRB) on corrosion behavior of carbon steel was studied in soils with moisture of 20% and 30%, by soil properties measurement, weight loss, polarization curve, and electrochemical impedance spectroscopy. The results show that carbamide decreased the soil redox potential and increased soil pH. In soil without SRB, carbamide made corrosion potential of Q235 steel much more positive and then inhibited corrosion. Meanwhile, in soil with SRB, 0.5 wt% carbamide restrained SRB growth and inhibited biocorrosion of Q235 steel. Corrosion rate of carbon steel decreased in soil with 30% moisture compared with that with 20% moisture.