Abstract
The present article provides an overview of the effect of hydrogen sulphide (H2S) on corrosion in polluted waters, including sea, river, brackish, geothermal and sewage waters. H2S is a weak, reducing acid which originates from sulphide minerals by natural acidification and/or from sulphur – bearing, decaying organic matter by bacterial action. Human and industrial activities increase the generation of corrosive gases, dissolved in water: CO2, H2S and NH3. Carbon steel, stainless steel, aluminium alloys and copper base alloys are corroded by H2S, producing metallic, non-stable sulphide films. The H2S content in various waters, the electrode potential pH (Pourbaix) diagrams for Fe and Cu in H2S containing systems, and the electrochemical and corrosion performance of steel in oxygen depleted, H2S polluted waters, which indicate active corrosion behaviour, are presented and discussed.