Investigation of Pathogen Removal by Anaerobic Sludge Digestion

The constituents removed in wastewater treatment plants include screenings, grit, scum, solids and biosolids. The solids and biosolids(formerly collectively called sludge) resulting from wastewater treatment operations are processes are usually in form of a liquid or semisolids liquid, which typically contains from 0.25 to 12 percent solids by weight, depending on the operations and processes used. Nowadays cost of treatment of biosolids(sludge) is about 60-70% cost of building wastewater treatment plant. In raw sludges and in mesophilically and thermophilically digested anaerobic sludges, large variations in numbers of viruses occurred over narrow ranges of numbers of fecal coliforms, total coliforms, and fecal streptococci, and Salmonella spp demonstrating that the bacteria were poor quantitative reflectors of the numbers of the viruses detected. Mesophilic and thermophilic digestion of anaerobic sludges destroyed all three indicator bacteria more rapidly than such digestion destroyed the viruses. This investigate potential of anaerobic sludge digestion to remove pathogens

Keywords:

Sludge , mesophilic , thermophilic , digestion