Membrane concentration procedures to assess quantitatively the effectiveness of the Tucson, Arizona pilot filter in removing enteroviruses from wastewater.

Abstract

A membrane virus concentration procedure was used to demonstrate the effectiveness of a tertiary treatment Pilot Filter in reducing the virus concentration of activated sludge effluent from the Tucson sewage treatment plant. This technique, which allows the quantitative determination of virus infective units per sample volume, showed that the Pilot Filter reduced the virus concentration by an average of 96%. No significant difference in removal of virus content was observed when the Pilot Filter was loaded from two different basins with horizontal travel distances of approximately 50 and 100 feet. For identification of virus types, a rapid and economical plastic panel micro culture technique showed an excellent correlation to the standard tube culture method in virus neutralization studies. Virus types detected during the eight month period of the study included poliovirus types 1, 2, and 3, one adenovirus, and several echovirus types. Preliminary studies were carried out to determine whether the membrane virus concentration procedure could be improved. These studies included pre-treatment of membranes with serum, use of a Dowex anion exchange column, and the investigation of an aluminum hydroxide virus adsorption method. Each of these procedures significantly improved the efficiency of virus recovery. The aluminum hydroxide method was superior to the other procedures and gave 100% recovery of virus added to wastewater samples.