The impact of additional nitrates in mild steel corrosion in a seawater/sediment system

• A significant increase in weight loss of the coupons with nitrate treatment.
• An increase in sulphate reduction bacteria in coupons with nitrate treatment.
• Biofilm/corrosion products were more evident in coupons with nitrate treatment.
• Increases in organic, decreases in Fe contents in coupons during incubation.

This paper investigates the impact of additional nitrate sources on mild steel coupon corrosion in a seawater/sediment system. The results show that addition of 5 mM of nitrate sources significantly increased the weight loss of coupons after 20 weeks. SEM results indicate increase in microbial populations and corrosive products in the non-autoclaved and the nitrate-treated environments. EDX analyses revealed an increase in contents of carbon, calcium, magnesium, phosphorus and sodium with the exception of iron with an increase in incubation time.