Effect of biofilm on cast iron pipe corrosion in drinking water distribution system: Corrosion scales characterization and microbial community structure investigation

Effect of biofilm on corrosion scales of cast iron pipe was studied with the biofilm community structure investigated by PCR-DGGE to give an explanation to MIC from the viewpoint of microbial phase. Corrosion scales were identified with XRD and XPS. It was demonstrated that biofilm can greatly affect element composition and crystalline phase of corrosion scales. Biofilm can accelerate corrosion in 7 d, but inhibit corrosion after 7 d, which was due to iron bacteria and iron reducing bacteria (IRB), respectively. DGGE fingerprinting gave a well explanation to this transition, which might be contributed to the change of biofilm microbial diversity.