addtitional

Question 1

44. Untreated wastewater enters a freshwater lake. Which environmental effect is most likely
    to occur first?
    a) Increased dissolved oxygen levels
    b) Increased microbial respiration in the water
    c) Decreased nutrient concentrations
    d) Reduced microbial growth
    e) Elimination of algae

Answer 1

b) Increased microbial respiration in the water

Question 2

In primary wastewater treatment, heterotrophic bacteria remove organic carbon from
wastewater primarily by:
a) Converting organic carbon into methane through fermentation
b) Oxidizing organic compounds to obtain energy
c) Using organic carbon as a terminal electron acceptor
d) Fixing CO₂ into organic carbon
e) Converting organic carbon into nitrate

Answer 2

b) Oxidizing organic compounds to obtain energy

Question 3

40. How do cyanobacteria pose a threat to drinking water quality?
    a) They cause food poisoning-like symptoms when ingested.
    b) They can produce neurotoxins that can persist in source waters.
    c) They can produce hepatotoxins that can persist in source waters.
    d) They lead to green or blue coloured drinking water, even after treatment.
    e) They can cause infections within the human body

Answer 3

b) They can produce neurotoxins that can persist in source waters.
c) They can produce hepatotoxins that can persist in source waters.

Question 4

41. How do wildfires increase the frequency of cyanobacterial blooms?
    a) The added heat from the fire promotes growth of cyanobacteria.
    b) Wildfires lead to increased input of organic matter and nutrients into watersheds.
    c) The decreased tree cover allows more access to sunlight.
    d) Wildfires kill all organisms other than cyanobacteria resulting in reduced
    competition

Answer 4

b) Wildfires lead to increased input of organic matter and nutrients into watersheds.
c) The decreased tree cover allows more access to sunlight.

Question 5

34. Main goals of secondary wastewater treatment include…
    a) Removing large debris
    b) Reducing the amount of organic carbon
    c) Reducing the amount of nitrogen
    d) Photosynthesis to produce oxygen
    e) Sterilizing the wate

Answer 5

b) Reducing the amount of organic carbon
c) Reducing the amount of nitrogen