External corrosion growth for buried steel pipeline in environment containing sulfate reducing bacteria

Abdullah, Arman

External corrosion growth for buried steel pipeline in environment containing sulfate reducing bacteria

dc.contributor.author	Abdullah, Arman
dc.date.accessioned	2024-08-21T14:49:47Z
dc.date.available	2024-08-21T14:49:47Z
dc.date.issued	2016
dc.description	Thesis (PhD. (Civil Engineering))
dc.description.abstract	Microbiological-induced corrosion (MIC) by the presence of sulfate reducing bacteria (SRB) is a serious threat to the long-term integrity of steel pipelines. Previous studies on the influence of SRB towards corrosion progress in Malaysia were focused more on marine environment. Considering that Malaysia has underground gas pipelines of about 2,500 km in length, serious efforts are needed to conduct detail investigations on the underground SRB threat. The aim of this research is to conduct an in-depth investigation on the performance of a local underground SRB strain from Sungai Ular area and benchmark this against ATCC7757TM strain in terms of bacterial growth and its influence on metal loss using derived empirical models. Two empirical models associated with MIC were derived using multilinear regression (MLR) and response surface method (RSM). The models acquired important corrosion data from field work and laboratory examination. A total of 48 steel coupons were buried at Sungai Ular site and these were retrieved every three months for a total of 18-month period. Metal loss and selected soil parameters were recorded throughout the research duration. Results have confirmed that the site was highly corrosive by referring to the established corrosion index. Analysis of the site data using Principal Component Analysis (PCA) and MLR model with high correlation, R2 of 0.86 showed that the SRBrelated parameters of pH, organic content, and sulfide have significant influences towards the corrosion rate. The field work results were later confirmed by laboratory experiments using an isolated local SRB strain from Sungai Ular based on onefactor- at-a-time-approach (OFAT) and RSM model whereby the pH was found to be the most dominant parameter that influenced bacterial growth and high corrosion rate. The DNA test of Sungai Ular SRB strain was found identical to the genus of ATCC7757TM. A comparative study has identified the Sungai Ular SRB strain as more aggressive due to the highest corrosion rate recorded at 6.2 mm/year, 11.4% higher than ATCC7757TM strain. The findings have successfully identified the SRBrelated parameters as the main contributor to the high corrosivity of Sungai Ular site using a comprehensive field work and laboratory experiment exercises. These can be highly beneficial guidelines to identify the main parameters that governed the mechanism of underground corrosion. The derived empirical models can be utilised by pipeline operators to design a better pipeline maintenance and structure integrity assessment against MIC threat
dc.description.sponsorship	Faculty of Civil Engineering
dc.identifier.uri	https://openscience.utm.my/handle/123456789/1280
dc.language.iso	en
dc.publisher	Universiti Teknologi Malaysia
dc.subject	Microbiologically influenced corrosion
dc.subject	Sulfate-reducing bacteria
dc.subject	Underground pipelines—Corrosion
dc.title	External corrosion growth for buried steel pipeline in environment containing sulfate reducing bacteria
dc.type	Thesis
dc.type	Dataset