Abstract |
The relative efficiencies of a buffered beef extract solution, sewage secondary effluent, and distilled water, were compared in a study designed to simulate leaching of indigenous enteric viruses from raw primary sewage sludge. The initial sludge liquid fractions, termed sludge liquor, and leachates from five successive washings with one of the three test fluids were removed from the sludge samples by vacuum filtration through stainless steel mesh screens. The highest calculated efficiency for virus leaching was 2.8 + or - 1.4 percent obtained with the beef extract solution. This indicated leaching to be a very inefficient process and may suggest that viruses present in sewage sludges will remain highly solids-associated following land disposal. |