Role of micro-organisms present in diesel fuel in the microbiological corrosion of carbon steel St3S

• Published in: Desalination and water treatment 2016-01, Vol.57 (3), p.1388-1398
• Main Authors: Slomczynski, Tomasz, Lebkowska, Maria
• Format: Article
• Language: English
• Subjects: Bacteria; Bacterial corrosion; Biofilm; Carbon steel; Carbon steel St3S; Corrosion; Diesel fuels; Discs; EDS; Interphase; Low carbon steels; Microbial corrosion; Microbiological corrosion; Organisms; Scanning microscope; Steels; Storage tanks; Sulfate reduction
• ISSN: 1944-3986; 1944-3994; 1944-3986
• DOI: 10.1080/19443994.2015.1030123

This study presents the microbiological and chemical characteristics of the water taken from diesel fuel storage tanks. The growth of micro-organisms was monitored in accordance with the ASTM standard test. The observations of damage to St3S steel were made using a scanning microscope, and the composition of the formed corrosion products was determined using an energy dispersive spectroscopy analyser. Micro-organisms causing microbiological corrosion (sulphate-reducing bacteria, iron bacteria, fungi) were found to develop in the water and on the steel discs. The growth of micro-organisms was the most intense on the discs placed at the water–fuel interphase. Microscopic studies revealed that the disc fragment exposed to the organic phase (fuel) practically did not undergo any corrosion. In the water phase, corrosion was uniform, and its intensity increased with the proximity to the interphase. The highest degree of corrosion was observed on the surface of the steel in the area in which the water was in contact with the fuel. In this area, discs were subject to strong corrosion and formation of rather deep corrosion pits was observed. Gravimetric studies revealed that the corrosion weight calculated in Vm and Vp units is much higher at the water–fuel interphase than in the aqueous phase.