Biological Corrosion in the Sewage System and the Sewage Treatment Plant

Biological corrosion of sewers and sewage treatment plants constitutes a serious problem and its effects result in the loss of billions of dollars a year. It is generally acknowledged that corrosion of concrete caused by microorganisms is associated with their production of sulphuric acid as the main metabolic product. The activity of the bacteria leads to the formation of the sulphur cycle in the system, and consequently to the formation of sulphuric acid, whose presence causes corrosion of concrete. Moreover, the presence of other organisms, such as nitrifying bacteria, fungi and organic acids also contributes to the degradation of the concrete. This article discusses the mechanism caused by biogenic inorganic acids.