Effect of concentration on virus removal for ultrafiltration membrane in drinking water production

Removal of pathogenic microorganisms as viruses during drinking water production was evaluated by ultrafiltration. Two enteric viruses (ADV 41 and CV-B5) were compared to the MS2 bacteriophage, largely used in literature and by membrane producers as enteric virus surrogate. The effect of feed concentration of viruses on the ultrafiltration efficiency has been assessed. For the three viruses, low retentions about 1 log were observed at the lowest concentrations. At higher concentrations, an increase of removal up to 3.0 log for CV-B5 and MS2 phage and 3.5 log for ADV 41 was observed. These results highlight the potential overestimation of UF efficiency during laboratory experiments realized at high concentrations, compared to low concentrations found in environmental resources used for drinking water production. Virus removals with Evian water and real groundwater were compared and groundwater achieved similar or slightly higher removals for the three viruses. Finally, impact of membrane ageing after chlorine exposure was checked. It was observed that membrane degradations, visible by a water permeability increase with exposure dose did not affect the removal of viruses at low feed concentrations.