Impacts of implementing a corrosion control strategy on biofilm growth

Biofilm growth and corrosion are interrelated processes in a drinking water distribution system. The presence of corrosion tubercles alters the qualit y of the water in many ways, such as increasing the number of available att achment sites on the walls of the, pipes for bacteria. Moreover, the presen ce of corrosion by-products significantly reduces chlorine disinfection and the efficiency of biofilm control. This study is aimed at evaluating the e ffect of implementing a corrosion control program on the development of bio film on distribution system pipe walls. No impacts were found during full s cale experimentation, however the results of a pilot-scale study carried ou t with annular reactors showed that, both in the presence and. absence of c orrosion by-products, the anti-corrosion chemicals tested (orthophosphates, a blend of orthopolyphosphates, and sodium silicates) had no impact on. bi ofilm development at the concentrations tested. Higher numbers of bacteria fixed on the walls of the reactors were associated with larger corrosion de posits on the annular reactors. Removing these corrosion deposits may have a positive impact an biofilm control in a distribution system.