SARAVANAN SANKARAN AND KARTHIKEYAN RAMALINGAM
Abstract
Water pipeline contains enormous diversity of microorganisms which straightly or obliquely stimulate the rust. Mostly anaerobic sulfate-reducing bacteria forever coexists offender alone. However, in this study a facultative anaerobic SRB strain of Citrobacter freundii was isolated from corroded pipeline sample and confirmed through 16S rRNA gene sequence. Its corrosion role on ApI-5L X60 carbon steel was 1.98 mg weight loss and corrosion rate was 0.2535 mm/year. SEM analysis also confirmed their Biofilm formation and pitting corrosion ability which ultimately lead to its assertive corrosion performance. Tetrakis-hydroxymethyl phosphonium sulfate was used to control the MIC, the corrosion inhibition efficiency was about 84%. The corrosion rate was reduced tenfold and optimum corrosion inhibition concentration remained 75ppm and the same to control the aerobic biofilms too. The corrosion though this novel strain and its inhibition phenomenon is valuable in water pipeline industries.