The following tests are mainly required for closed industrial water systems such as Chilled Water and LPHW circuits where the bacteria described can cause large amounts of corrosion if left untreated.
These bacteria are capable of breaking down sulphate to sulphide with the resulting problems of formation of hydrogen sulphide. Hydrogen sulphide is a toxic gas in large quantities and will also contribute to corrosion of pipework in a closed system.
Organisms in this group are capable of using nitrate and nitrite containing compounds as an energy source, which in turn produces nitrogen gas. Again the action of these organisms can cause problems such as corrosion in a closed industrial system.