Microbiological Induced Corrosion A Cited Case in Ohaaki Geothermal Power Station

Abstract

Most of the corrosion on the materials comprising the circulating water (CW] gcitea in Ohaaki are microbiologicallv induced. Sulfur, nitrogen and slime producing bacteria are recognised in the deterioration of the materials since they produced strong acids @.e. HSOJ during metabolism. The main defence wherein corrosion is controlled is by dosing a biocide in the circulating water, and coating the inner wall of the cooling tower which is ôout of the reach ÆÆ of biocide. A spray gun was installed in order to reach the vapour zone S wall with biocide treated circulating water. Therefore, the case of microbiologically induced corrosion cited in Ohaaki reduces the efficiency and qrraliQ of the materials making the CTY systeui, thus increases maintenance costs.