Microbiologically influenced corrosion of mild steel in some water environments

Usman, Muhammad Tukur; Bishir, Usman

Algerian Journal of Materials Chemistry
Volume 3, Numéro 1, Pages 1-10
2020-01-07

Microbiologically Influenced Corrosion Of Mild Steel In Some Water Environments

Authors : Usman Muhammad Tukur . Bishir Usman .

Abstract

Microbiologically influence corrosion of mild steel in effluent, Seawater and fresh water investigated using Weight loss, Culturing technique, Fourier Transforming Inferred Spectroscopic (FTIR), Scanning Electron Microscope (SEM) and X-ray florescence (XRF) methods. Weight loss was used to observed change in weight on metal surface due to accumulations of corrosion products. Culturing technique was used to identify the presences of microorganisms such as bacteria and fungi nutrient agar and potato dextrose agar (PDA) responsible for changes in weights of water environments thrive and produce acidic by products. Effluent was found to contains Escherichia coli (E. coli) bacterial species with average populations of 3.25 x 10-3cfu/ml and 3.28 x 10-3cfu/ml, Sea water was found to contains Streptococcus pneumonia bacterial species with average populations of 1.40 x 10-3cfu/ml and 2.53 x 10-3cfu/ml and Staphylococci aureus bacterial species was found in Fresh water with average populations of 1.07 x 10-3cfu/ml and 2.33 x 10-3cfu/ml before and after immersion of metal coupons respectively. Similarly, same fungal species identified in both effluent and Fresh water, that is Mucormycosis species with average populations of 9.01 x 10-3cfu/ml and 7.22 x 10-3cfu/ml respectively, and Rhizopus species with average populations of 2.98 x10-3cfu/ml was found in Seawater after immersion of carbon coupons. XRF and Atomic Absorption Spectroscopy (AAS) results confirmed the presence of elements in the water environments such asFe, Ni, Zn, Cu, Mn, Pb, Cr, Co, Nb, Mo, Sn and Cs in effluent, Fe, Ni, Zn, Cu, Mn, Pb, Cr, Co, Br, Sn, Nb, Mo, Cd, Ba and La in seawater while Fe, Ni, Zn, Cu, Mn, Pb, Cr, Co, Nb, Mo, Ba and La in fresh water. FTIR results confirmed the presence of functional groups such as amines, amides, Imines, aldehydes which are found in metabolites produced by microorganisms and some of these metabolites produced have a great impact, while some are said to be as waste end products as corrosion products. SEM shows the metal surface microgram. These changes in compositions of elements and weight of mild steel is due to the presences of extensive micro pitting on the surface.