- Scenario A Graduate Student Went To A Wastewater Treatment Plant To Collect Untreated Wastewater Samples For His Resear 1 (256.7 KiB) Viewed 48 times
Scenario: A graduate student went to a wastewater treatment plant to collect untreated wastewater samples for his resear
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Scenario: A graduate student went to a wastewater treatment plant to collect untreated wastewater samples for his resear
Scenario: A graduate student went to a wastewater treatment plant to collect untreated wastewater samples for his research. During sampling, 1 mL of raw sewage splashed onto his bare hands. He washed his hands afterward using an antibiotic soap, which claims to kill 99% of bacteria. Estimate how many fecal coliforms (note that fecal coliforms are a class of “indicator organisms”) are still on his hands after washing. . How much reduction is required to reduce the fecal coliform level to less than 1 CFU on the hands? Table 2. Microorganism concentrations in untreated municipal wastewater Microorganisms Concentrations (100 mL-') Fecal coliforms 105-107 Fecal streptococci 104-106 Clostridium perfringens 103-105 Salmonella 102-104 Shigella 1-103 Pseudomonas aeruginosa 103-104 Enteric viruses 103-104 Helminth ova 1-103 Giardia lamblia cysts 10-104 Cryptosporidium oocysts 10-10 Entamoeba histolytica cysts 102-105 Source: National Resource Council 1996