Abstract:
The effect of microbial corrosion on pipeline using different soil media was investigated. The soil samples utilized in this experiment included clay, sandy and loamy. These samples were obtained from Oba Ile and Oke Aro all within Akure metropolis. The soil samples (clay, sandy and loamy) each weighed at 8kg were poured into a mini-bucket. Control samples was set up from each soil sample and to the control samples, water without activator (H2SO4) was added. To the other soil samples was added different molarity of an already prepared hydrogen tetraoxosulphate (VI) acid (H2SO4) which serves as an activator. This set up was left for periods of two weeks to prevent eat up of the substrates by the acid. The substrates were obtained from a cylindrical metal pipe of known composition with a diameter of 40 mm and length 50 mm. These substrates were immersed in the soil samples. The corrosion potential of the immersed substrates was taken daily using an oscilloscope while the pH of the soil in which the substrates were immersed was measured daily using the digital pH meter. It was discovered that both corrosion and passivation took place as a result of increase and decrease in the corrosion potential of the substrates. Microbial growth also took place within the pH range of 4 and 7. From all the setups, it was discovered that microbial corrosion took place in substrates immersed in soil with acidic molarity of 0.02 as there was no appreciable change in pH after 96hours of exposure time. A model was developed from the readings obtained from one of the samples which helped in predicting the pH of soil samples in years to come.
