Investigations of Microbiologically Influenced Corrosion (MIC) of Submerged Steel and Wooden Ship Wrecks and the Role that Bio-Concretions Play in these Degenerative Processes

摘要

Traditionally microbiologically influenced corrosion [MIC] processes have been linked to the activities of the sulfate reducing bacteria (SRB). Here the major daughter product is hydrogen sulfide (H_2S) which then triggers electrolytic corrosion. Corrosion can be initiated when H_2S gas comes into contact with the surfaces of steels. Microbiological investigations of MIC have been found to involve a sequence of events including: Biomass attaching to surfaces, growth activities, impacts on the supporting matrices below the attachment surfaces, and then corrosion of the matrices commonly leading to structural collapse. From the studies primarily on mild steels, but also including concrete and wood, a pattern of microbiological activity has been observed that commonly occurs when corrosion risks are significant. These include the physical and chemical nature of the surface to which the biomass attaches and grows; the nature of the environment at the surface interface; the form of biomass growth; interactive nature of the biomass with the matrix; and the final states of stabilization or destruction of the matrix and associated biomass. Critical to the MIC corrosive process is the form and function of the associated attached active biomass interacting with the surfaces of the potentially vulnerable matrix.