Basic Wastewater Operations- Chapter 3 Test Questions with Verified Answers Latest Update 2024
( Graded A+)
T/F: Because wastewater is mostly water, it weighs 8.34 lbs/gal. - Answers True
T/F: Labs report many characteristics of wastewater as milliliters per Liter (mL/L) - Answers False; It is
reported in milligrams per Liter (mg/L).
T/F: Wastewater characteristics are divided into three primary groups: bacteriological, physical, and
chemical. - Answers False; There are four primary groupings, the fourth category being radiological.
T/F: Bacteria are seen with a telescope and are present in soil, water, air, decaying organic matter, and
intestinal tract of humans and animals. - Answers False; Bacteria are visible when using a microscope.
T/F: Some bacteria cause disease and are called pathogens. - Answers True
T/F: One way to classify bacteria is by their oxygen use: aerobic, facultative, and anaerobic. - Answers
True
T/F: Aerobic bacteria require dissolved, uncombined (free) nitrogen. - Answers False; Aerobic bacteria
need dissolved, uncombined oxygen.
T/F: Anaerobic bacteria cannot live when chemically combined oxygen is present. - Answers False;
Chemically combined oxygen is necessary for anaerobic bacteria.
T/F: Facultative bacteria live with free oxygen or chemically combined oxygen. - Answers True
T/F: Fresh domestic wastewater contains dissolved oxygen. - Answers True
T/F: Septic wastewater is dark, has agreeable odor, and contains dissolved oxygen. - Answers False;
Septic wastewater has an unpleasant odor and no dissolved oxygen.
T/F: Septic wastewater contains fragrant gases produced by bacteria. - Answers False; Odorous gases
T/F: Some chemical characteristics of wastewater include solids, grease, DO, pH, and gases. - Answers
True
T/F: Solids include total, suspended, dissolved, settleable, inorganic, organic, and soft and hard solids. -
Answers False; Doesn't include soft and hard solids.
T/F: Suspended solids can be filtered out, and dissolved solids pass through a filter. - Answers True
T/F: Settleable solids are dissolved solids of sufficient weight to settle when left standing for a time. -
Answers False; They are suspended solids.
T/F: Inorganic material, suspended or dissolved, is sand, grit, and minerals. - Answers True
T/F: Two other classifications of solids are inorganic (ash) and organic (volatile). - Answers True
, T/F: Examples of organics are sugar, butter, leather, paper, and iron. - Answers False; Iron is not an
organic solid
T/F: Organic solids are volatile, combustible solids found by burning the residue from the total solid test
or the filter from the TSS test. - Answers True
T/F: The ash (fixed solids) left after burning consists of inorganic solids. - Answers True
The three primary types of organics are __________________, proteins, and grease.
A. Minerals
B. Leather
C. Carbohydrates
D. Paper - Answers C. Carbohydrates
_______________ in raw wastewater comes from the water supply.
A. Facultative bacteria
B. Dissolved oxygen
C. Organic solids
D. Inorganic grease - Answers B. Dissolved oxygen
When dissolved oxygen is present, it indicates the wastewater is _______________.
A. Septic
B. Odorous
C. Anaerobic
D. Fresh - Answers Fresh
As the water temperature rises, the DO saturation level will ____________.
A. Decrease
B. Increase
C. Not change
D. None of the above - Answers A. Decrease
The dissolved oxygen test must be performed as soon as a sample is taken because the oxygen levels
can ____________ change.
( Graded A+)
T/F: Because wastewater is mostly water, it weighs 8.34 lbs/gal. - Answers True
T/F: Labs report many characteristics of wastewater as milliliters per Liter (mL/L) - Answers False; It is
reported in milligrams per Liter (mg/L).
T/F: Wastewater characteristics are divided into three primary groups: bacteriological, physical, and
chemical. - Answers False; There are four primary groupings, the fourth category being radiological.
T/F: Bacteria are seen with a telescope and are present in soil, water, air, decaying organic matter, and
intestinal tract of humans and animals. - Answers False; Bacteria are visible when using a microscope.
T/F: Some bacteria cause disease and are called pathogens. - Answers True
T/F: One way to classify bacteria is by their oxygen use: aerobic, facultative, and anaerobic. - Answers
True
T/F: Aerobic bacteria require dissolved, uncombined (free) nitrogen. - Answers False; Aerobic bacteria
need dissolved, uncombined oxygen.
T/F: Anaerobic bacteria cannot live when chemically combined oxygen is present. - Answers False;
Chemically combined oxygen is necessary for anaerobic bacteria.
T/F: Facultative bacteria live with free oxygen or chemically combined oxygen. - Answers True
T/F: Fresh domestic wastewater contains dissolved oxygen. - Answers True
T/F: Septic wastewater is dark, has agreeable odor, and contains dissolved oxygen. - Answers False;
Septic wastewater has an unpleasant odor and no dissolved oxygen.
T/F: Septic wastewater contains fragrant gases produced by bacteria. - Answers False; Odorous gases
T/F: Some chemical characteristics of wastewater include solids, grease, DO, pH, and gases. - Answers
True
T/F: Solids include total, suspended, dissolved, settleable, inorganic, organic, and soft and hard solids. -
Answers False; Doesn't include soft and hard solids.
T/F: Suspended solids can be filtered out, and dissolved solids pass through a filter. - Answers True
T/F: Settleable solids are dissolved solids of sufficient weight to settle when left standing for a time. -
Answers False; They are suspended solids.
T/F: Inorganic material, suspended or dissolved, is sand, grit, and minerals. - Answers True
T/F: Two other classifications of solids are inorganic (ash) and organic (volatile). - Answers True
, T/F: Examples of organics are sugar, butter, leather, paper, and iron. - Answers False; Iron is not an
organic solid
T/F: Organic solids are volatile, combustible solids found by burning the residue from the total solid test
or the filter from the TSS test. - Answers True
T/F: The ash (fixed solids) left after burning consists of inorganic solids. - Answers True
The three primary types of organics are __________________, proteins, and grease.
A. Minerals
B. Leather
C. Carbohydrates
D. Paper - Answers C. Carbohydrates
_______________ in raw wastewater comes from the water supply.
A. Facultative bacteria
B. Dissolved oxygen
C. Organic solids
D. Inorganic grease - Answers B. Dissolved oxygen
When dissolved oxygen is present, it indicates the wastewater is _______________.
A. Septic
B. Odorous
C. Anaerobic
D. Fresh - Answers Fresh
As the water temperature rises, the DO saturation level will ____________.
A. Decrease
B. Increase
C. Not change
D. None of the above - Answers A. Decrease
The dissolved oxygen test must be performed as soon as a sample is taken because the oxygen levels
can ____________ change.
