During treatment of water to make it potable, about 90% of the microbes are removed
A: by preliminary fermentation
B: in the sedimentation step
C: by
... [Show More] treatment biosensors
D: by treatment with chlorine or ozone
E: in the filtration step - correct answer E
Potable water is water that
A: is considered safe to drink because it is completely sterile
B: contains biosensors
C: contains a dangerous number of microorganisms
D: is transferred from one place to another
E: Contains low amounts of microorganisms and is considered safe to drink - correct answer E
Which of the following is added during water or sewage treatment to promote flocculation
A: sludge
B: PHA
C: BOD
D: Alum - correct answer D
During chemical treatment of drinking water and wastewater, which of the following microbes are LEAST LIKELY to be INACTIVATED OR KILLED
A: algae
B: viruses
C: fungal spores
D: bacteria - correct answer B
In which step is the MOST of the organic content of sewage removed
A: primary treatment
B: secondary treatment
C: tertiary treatment
D: sludge treatment - correct answer B
Ultraviolet light (or chlorinated) treated water contains
A: no viruses
B: no bacteria at all
C: no endospores
D: no cysts
E: a decreased microbial load - correct answer E
Which of the following microorganisms is the most commonly used indicator organism for water quality testing?
A: Eschericha coli
B: Salmonella spp.
C. Shigella spp.
D: Streptococcus thermophilus
E. Hepatitis A virus - correct answer A
Which of the following statements concerning the biochemical oxygen demand (BOD) is correct
A: it is a measure of the amount of oxygen in water
B: it is proportional to how potable water is
C: it is used as a bioreceptor index
D: it is a measurement of the amount of oxygen that aerobic bacteria require to fully metabolize organic wastes in water
E: It is a filter system to purify drinking water - correct answer D
Nitrogen fixation is performed by which of the following microbes?
A: algae
B: fungi
C: protists
D: bacteria - correct answer D
City of Santa Rosa water treatment facility diverts their solids to a land application program. In order to render the bio-solids a class A product which is non-pathogenic, what is done?
A: Bio-solids are passed through activated charcoal and passed through ultraviolet light
B: After dewatering the anaerobic digest the bio-solids are hauled to landfills
C: combine bio-solids with curbside green waste
D: 30 days active compositing, allowing temperature to spike up to 150F for 3 consequential days - correct answer D
Nematodes
A: stalked ciliates
B: free-swimming ciliates
C: filamentous bacteria - correct answer B
Nocardia
A: stalked ciliates
B: free-swimming ciliates
C: filamentous bacteria - correct answer C [Show Less]