Processing procedures for recovering enteric viruses from wastewater sludges

A powdered beef extract specially formulated for recovering viruses from environmental samples and designated as beef extract V was evaluated using indigenous and viral seeded wastewater sludge samples. When beef extract V was used to process activated and aerobically digested sludge solids, virus recoveries were shown to be similar to other methods that used commercially available supplemented beef extract. When used to process other sludge solids (primary and activated without primary clarification), cytotoxicity resulted in the BGM cell line used for virus assay. When these sludge solids were processed with the supplemented commercially marketed beef extract cell toxicity did not occur. Metal concentrations in the processed sewage sludge eluates were analyzed, but based on the levels observed they could not be shown as the source of the cytotoxicity. This did not exclude possible synergistic cytotoxic effects or organometal complexes. The commercially marketed beef extract was supplemented with either a floccing aid (FeCl3), a filter aid (Celite) or a floc prepared from paste beef extract. The paste beef floc supplement proved to be the most useful and reliable method for processing for viruses from wastewater sludge solids.