AWWA REUSE52103

Untreated municipal wastewater contains microorganisms of fecal origin, such as bacteria, viruses, protozoans, and helminths, which are the principal agents of infectious diseases. In the Valley of Mexico, untreated wastewater is utilized for the agricultural irrigation of 90,000 hectares located to the north of Mexico City in the Mezquital Valley. In order to meet regulations, the effluent must be treated. Although the removal of pathogenic microorganisms in conventional treatment systems has been well documented, little research has been done to determine the efficiency of Advanced Primary Treatment (APT) coupled with filtration and chlorine disinfection. This study analyzed the reduction of microorganisms in a system composed of Advanced Primary Treatment (APT), sand filtration and disinfection. The regrowth of bacteria was monitored after a prolonged period (48 hours). The measurements were undertaken in situ, in the principal sewer outlets of Mexico City in an APT pilot plant followed by a sand filter and a chlorination tank. Includes 12 references, tables, figures.