Removal of bacterial indicators and pathogens from dairy wastewater by a treatment system

Abstract

An integrated wastewater treatment facility at a dairy in Glendale, Arizona, consisting of an upper subsystem (solids separators, anaerobic lagoons, and aerobic ponds) and lower subsystem (wetland subsystems) has been proven to be successful in reducing indicator organisms and potential pathogens (bacteria, enteric viruses, and parasites). The collection sump of the new integrated system collects all dairy wastewater and pumps it to solid separators, which then flows by gravity to anaerobic lagoons and aerobic ponds. The upper subsystem achieved significant microbial reductions of >98 percent for total coliform, >91 percent for coliphage, >95 percent for enterococci, >91 percent for Listeria monocytogenes, and >99.9 percent for Cryptosporidium . Additional reductions although limited were observed in the outflow from the wetland cells.