Occurrence of Pathogens in Municipal Wastewater and their Survival during Wastewater Treatment

Pathogens can enter municipal wastewaters from several sources including homes, hospitals and slaughter houses. They are identified, typical levels found in sludges are given along with infectious doses, and their survival on crops and in the soil presented. As wastewater is cleansed, organisms present are concentrated in the sludge. Recent data indicates that the numbers of pathogens appearing in sludges are decreasing. The United States' regulations for the management of sewage sludge were designed to protect human health by minimizing the contact of humans with pathogenic microorganisms. Processes like pasteurization are employed to reduce pathogens below their analytical detection limits, while processes like anaerobic digestion are combined with access restrictions to reduce pathogens. Issues with the present disinfection alternatives such as their only being concerned with the presence or absence of certain pathogens like enteric viruses or Ascaris sp. are discussed and remedies suggested. Innovative and alternative methods for disinfection are frequently proposed, some are discussed here, and it is important to understand how the stressors employed by the process contribute to its reduction of pathogenic bacteria, viruses, protozoa and parasites.