The propagation cycle that occurs in acid mine drainage is caused by
A) reduction of Fe3+ by sulfuric acid.
B) the oxidation of sulfide to sulfuric acid by microbial oxidation of iron (Fe3+).
C) microbial sulfate reduction.
D) low pH and high oxygen concentrations.
Which of the following is the first, or initiator, reaction in acid mine drainage and leaching?
A) oxidation of reduced sulfides to sulfate and the release of reduced iron (Fe2+)
B) rapid spontaneous reduction of oxidized iron (Fe3+)
C) rapid oxidation of sulfides to sulfate by oxidized iron (Fe3+)
D) microbial sulfate reduction
Treatment of drinking water by UV irradiation is effective at ________, but it does NOT remove ________.
A) killing bacteria and eukaryotic pathogens / odor- and taste- altering organic compounds
B) killing viruses / bacteria and eukaryotic pathogens
C) removing order- and taste- altering organic compounds / viruses
D) killing bacteria / viruses and eukaryotic pathogens
The goal of tertiary wastewater treatment is to sharply reduce the levels of ________ from the final effluent.
A) organic compounds
B) heavy metals
C) methane
D) inorganic nutrients
Water distribution systems contain
A) very few bacteria or other microorganisms.
B) biofilms that may harbor opportunistic pathogens.
C) numerous grazing protists that consume bacteria.
D) biofilms that may harbor opportunistic pathogens and numerous grazing protists that consume bacteria.