The Disinfection Efficacy of Chlorine on Sulfate-reducing Bacteria and Iron Bacteria in Water Supply Systems

Abstract

Sulfate reducing bacteria (SRB) and iron reducing bacteria (IRB) that widely exist in water supply networks are the main microorganisms leading to metal corrosion in pipelines. Chlorine is widely used in drinking water supply systems for sterilization. Since the supply system is complex, the concentration of chlorine varies in different sections. The concentration of chlorine with SRB declined rapidly after 10 mins and reached 0 mg/L finally whereas it decreased more slowly with IRB. If the concentration of chlorine is lower than 0.2mg/L, IRB cannot be sterilized. It indicates that at the end of water pipes where the concentration of chlorine is required to be 0.05mg/L there will be accumulated with IRB which can cause corrosion to penetrate deeply. Chlorine will not be effective since the concentration is below the minimum requirement of removing IRB.