Virus Removal by Diatomaceous Earth Filtration

An investigation was made to determine the removal of bacteria viruses, T4 and MS2, by filtration through uncoated and polyelectrolyte coated diatomaceous earth (DE). Using a bench scale continuous-flow filtration apparatus, it was found that there was little, if any, removal of the viruses by uncoated filter media. However, filtration through diatomaceous earth coated with cationic polyelectrolyte resulted in significant virus removal. In studying the removal of viruses from a natural ground-water source, it was observed that organic matter in the ground water interfered with virus removal. The efficiency of virus removal, using both coated and uncoated DE, was also evaluated with respect to several physical and chemical variables, including pH, filtration rate, type of DE filter medium, and turbidity. All of these variables were found to affect the removal of viruses to some degree.