Investigation Of The Microbial-Induced Corrosion Potential Of Soils In Southern Ijaw Lga In Niger Delta, Nigeria

Abstract

Investigation of sulphate-reducing bacteria induced corrosion potential of soils along 18-inch 45km Tebidaba/Brass underground oil pipeline in Southern Ijaw LGA of Bayelsa State, Nigeria, is carried out experimentally. The analysis involves determination of some physico-chemical parameters of soils in the pipeline route, and testing corrosion products formed on the surfaces of X60 steel coupon buried in the soils for one year. It is shown that the soils are clayey in nature and highly corrosive with high population of sulphate-reducing bacteria (104 – 106 cfu/g). The ranges of other measured properties of the soils (pH (4.8 – 5.2), temperature (17 – 21oC), water content (79 – 89 %), organic matter (10.7 – 15.6 % dry wt), redox potential (–79 to –95mV), sulphate (0.8 – 13.6mg/l)) favour growth of sulphate-reducing bacteria. Black deposits on the surfaces of the buried coupons are iron sulphide resulting from attack on the metal by sulphate-reducing bacteria in the soils.

Keywords: sulphate-reducing bacteria; soil; corrosion; pipeline; crude oil

Global Journal of Pure and Applied Sciences Vol. 14 (3) 2008: pp. 325-330