Indicator Organisms in Wastewater Treatment Wetlands Jepson Sutton SWES 574 10-31-02.
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Transcript of Indicator Organisms in Wastewater Treatment Wetlands Jepson Sutton SWES 574 10-31-02.
Indicator Organisms in Wastewater Treatment Wetlands
Jepson Sutton
SWES 574
10-31-02
Indicator Organisms
• The detection of pathogenic organisms is a time-consuming, labor-intensive task, requiring highly trained technicians
• For this reason, scientist have identified certain organisms that, when detected, are a definitive indication of fecal contamination.
Indicator Organisms
• Indicator organisms are considered normal flora (always present) in the digestive system of all warm-blooded animals, including humans.
• The detection of indicator organisms suggests that enteric pathogenic microorganisms may also be present due to the fecal contamination.
Characteristics of an effective Indicator
• It is normal flora of warm-blooded animals • It is present when pathogens are present,
and undetected in uncontaminated samples • The indicator should be found in greater
concentrations than pathogens. • It should have a similar resistance to
environmental stress and water treatment processes as the pathogen.
Characteristics of an effective Indicator
• It must require a host for replication. (eliminates replication in the environment)
• Rapid, easy, and inexpensive detection methods
• Nonpathogenic
Types of indicator organisms
• Total coliforms – First group of indicators developed– Problematic because of the ability of some species to
replicate in the environment
• Fecal coliforms – Subgroup of Total coliforms– Restricted to fecal origins
• Fecal Streptococci – Primarily an indication of animal fecal pollution– FC/FS ratio
Types of indicator organisms
• Anaerobic bacteria – Clostridium: spore forming bacteria /
environmental resistance– Bacteroides: limited environmental resistance
• Bacteriophage – Viruses that require certain bacterial hosts for
replication– Indication of both bacterial and viral
contamination.