[Effect of suspended particles on biofilms formation in simulated potable distribution]

The effluent of the granular activated carbon in the treatment process was divided into three parts, the first part through 2 microm microfiltration membrane, the second part through 8 microm micro-filtration membrane, and with the third part being remained itself as comparison. Disinfection assays were performed with chlorine (NaClO) 0.5 mg/L. Studying the biofilms formation process separately in the three parts was performed with the interesting in particles. Particles may transport bacteria which were highly resistant to disinfection by chlorine to the distribution system and became entrained in biofilms, and could make the biofilms instable and put off the maximal biomass of biofilms. During the experiment the time when the 2nd BAR reach maximal biomass of biofilms was later 4 days than that of the 1st BAR, and the time when the 3rd BAR reach maximal biomass of biofilms was later 8 days than that of the 2nd BAR. The size ranges and quantity of particles impacted the effluent biomass. The more and the bigger particles were, the more effluent biomass was.