ABSTRACT
One of the major groups of human pathogens found in wastewater and its sludges is viruses. This chapter focuses on the inactivation of human enteric viruses during plant operations commonly used to produce and treat sludges, and the effects of more elaborate sludge disinfection processes on this group of human pathogens. Lime and other chemicals are used to remove solids from wastewater by coagulation and sedimentation, and these same chemicals can be used to stabilize sludge. The established tendency of enteric viruses to remain or become bound to the particulate matter in sewage indicates that a large percentage will eventually become ingredients of sludge during treatment plant operations. Heat is one of the most effective methods for inactivating viruses. Temperatures attained during efficient composting should cause thorough viral inactivation even though certain ingredients of sludge such as detergents can stabilize some enteric viruses against heat.
