Investigation on corrosion control of mild steel buried in soil by spent FCC catalyst coating

Effects of aerobic and anaerobic bacteria on corrosion behaviour of mild steel coated with modified spent FCC catalyst have been examined in soil extract solutions (SES) and that buried in soil. Coating of modified spent FCC catalyst was found to inhibit the growth of bacterial isolates from the soil which is represented as zone of inhibition. Efficacy of spent FCC catalyst was studied for the coated coupons immersed in SES. Cracks and interstices were found on uncoated coupons due to corrosion whereas coated surface remained unaffected. This is confirmed by the SEM analysis. It was also seen that coated coupon was undamaged under buried-in-soil conditions for 30 days.