Corrosion Control in Sewers

Abstract

Cement concrete sewers, either cast-in-place or pre-cast(like spun pipes or hume pipes), have been used for over a century for large sewers. In the presence of high concentrations of dissolved sulphide, sewers are likely to suffer serious damage when the hydrogen sulphide generated in them is oxidised to sulphuric acid. The first indication of possible trouble to concrete structures from H2S was given by Hering in 1881. The whole process involves two biochemical and one chemical reactions wherein: (1) H2S is formed (2) soluble sulphide is oxidised to sulphuric acid, and (3) concrete is attacked by the sulphuric acid