Author/Authors :
Sahrani, Fathul Karim Universiti Kebangsaan Malaysia - School of Environment and Natural Resource Sciences,Faculty of Science and Technology, Malaysia , Ibrahim, Zaharah Universiti Kebangsaan Malaysia - School of Environment and Natural Resource Sciences,Faculty of Science and Technology, Malaysia , Aziz, Madzlan Universiti Kebangsaan Malaysia - School of Environment and Natural Resource Sciences,Faculty of Science and Technology, Malaysia , Yahya, Adibah Universiti Kebangsaan Malaysia - School of Environment and Natural Resource Science,Faculty of Science and Technology, Malaysia
Abstract :
Corrosion caused by sulphate-reducing bacteria (SRB) isolated from seawater nearby to Pasir Gudang has been studied. The test coupon was a AISI 304 stainless steel. Potential and corrosion rate measurements were carried out in various types of culturing solutions, with SRB1, SRB2, combination of SRB1 SRB2 and without SRBs inoculated (sterilized). From Tafel plots a higher corrosion rate has been found in medium inoculated with SRBs than that of the sterilized medium (control). When SRBs were present in the medium, the Tafel plot shifted towards more negative values (Ecorr was shifted to much less anodic values) and increase in current density compared to that of the sterilized medium (control). Localized corrosion was observed on the metal surface, and it was associated to the SRB activity. X-ray analysis (EDAX) showed that the corrosion product has higher content of sulphur for medium containing SRBs than that of the sterilized medium. X-Ray Diffraction analysis carried out on corrosion products which showed the presence of iron sulphide. This indicates the influence of the presence of SRB in corrosion process
Keywords :
sulphate , reducing bacteria , stainless steel , electrochemical test
