Chap 2 Why Treat Wastes?

Question 1

Wastes should have a pH similar to that of the receiving water before they are discharged. True or False?

Answer 1

True

Question 2

Chemical Changes in living organisms are involved in nutrient cycles. True or false?

Answer 2

True

Question 3

Fresh flowing mountain streams are always free of “impurities”. True or false?

Answer 3

False

Question 4

An operator’s best defense against infections and disease is good personal hygiene. True or false?

Answer 4

True

Question 5

Domestic wastewater contains only organic wastes. True or false?

Answer 5

False

Question 6

An indication of possible pathogenic bacterial contamination is the presence of coliform group bacteria. True or false

Answer 6

True.

Question 7

To work for their benefit in treatment plants, natural cycles are controlled and accelerated by treatment plant operators. True or false

Answer 7

True.

Question 8

Best Answer: Pathogenic organisms are commonly killed by which wastewater treatment process?

1. Activated sludge
2. Disinfection
3. Primary sedimentation
4. Sterilization

Answer 8

2. Disinfection

Question 9

Best Answer: In wastewater treatment plants, how can the sludge and scum be removed?

1. Aerobic treatment
2. Biological treatment
3. Primary treatment
4. Secondary treatment

Answer 9

3. Primary treatment

Question 10

Best Answer: Oxygen depletion in a stream is caused by what factor?

1. Aerobic bacteria feeding on oxidizable wastes
2. Chemical reactions involving oxygen
3. Loss of dissolved oxygen to the atmosphere.
4. Respiration by fish.

Answer 10

1. Aerobic bacteria feeding on oxidizable wastes

Question 11

Best Answer: Imhoff cones are used to measure which water quality indicator?

1. Dissolved solids
2. Floatable solids
3. Settleable solids
4. Suspended solids

Answer 11

3. Settleable solids

Question 12

Best Answer: Why are nutrients undesirable in treated wastewaters?

1. Create taste-and odor-producing substances.
2. Encourage excess algal and plant growth
3. Interfere with aquatic life.
4. Produce toxic substances.

Answer 12

2. Encourage excess algal and plant growth

Question 13

Best Answer: Sulfur compounds are converted to which compound when no dissolved oxygen is present in water?

1. Potential for excess algal growth
2. Presence of inadequately treated wastewater
3. Probable presence of pathogenic organisms
4. Toxic substances harmful to aquatic life

Answer 13

2. Presence of inadequately treated wastewater

Question 14

Best Answer: Floatable solids are undesirable in a plant effluent because they indicate which problem?

1. Potential of excess algal growth
2. Presence of inadequately treated wastewater.
3. Probable presence of pathogenic organisms.
4. Toxic substances harmful to aquatic life.

Answer 14

2. Presence of inadequately treated wastewater.

Question 15

Multiple Choice: major types of wastes include which of the following?
1. dilution wastes.
2. Inorganic wastes.
3 Organic wastes.
4. Radioactive wastes.
5. Thermal wastes.

Answer 15

2. Inorganic wastes.
   3 Organic wastes.
3. Radioactive wastes.
4. Thermal wastes.

Question 16

Multiple Choice: Sources of organic industrial wastes could include which of the following industries?

1. Dairy processing
2. Meat packing
3. Printed circuit board manufacturing.
4. Tanning
5. Water softening.

Answer 16

1. Dairy processing
2. Meat packing
3. Tanning

Question 17

Multiple Choice: Oxygen depletion in a steam can cause what kinds of problems?

1. Algal blooms
2. Fish kills
3. Illness
4. Odors
5. Supersaturation

Answer 17

2. Fish kills

4. Odors

Question 18

Multiple Choice: Sludge and scum must be removed from wastewater in treatment plants for which of the following reasons?

1. Are unsightly.
2. May be a source of odors
3. May cause oxygen depletion
4. Represent a loss of a valuable resource
5. Should be reclaimed and recycled

Answer 18

1. Are unsightly.
2. May be a source of odors
3. May cause oxygen depletion

Question 19

Multiple Choice: The biological activities of algae can appreciate affect which water quality indicators?

1. Alkalinity
2. Dissolved oxygen
3. Pathogens
4. pH
5. Toxicity

Answer 19

1. Alkalinity
2. Dissolved oxygen
3. pH

Question 20

Multiple Choice: Hydrogen sulfide can cause what kinds of problems?

1. Corrosion
2. Explosive mixture with air
3. Odors
4. Paralyzes respiratory system
5. Toxic gases

Answer 20

All of the answers:

1. Corrosion
2. Explosive mixture with air
3. Odors
4. Paralyzes respiratory system
5. Toxic gases

Question 21

Multiple Choice: The intent of the NPDES permit program is to make the nation’s waters suitable for which beneficial uses?

1. Amount of flow into the receiving stream.
2. Flsh life
3. Navigation
4. Swimming
5. Wildlife

Answer 21

2. Flsh life
3. Swimming
4. Wildlife

Question 22

Multiple Choice: Which of the following factors can determine whether any problems are caused in receiving waters by the discharge of treated wastewaters?

1. Amount of flow in the receiving steam.
2. Characteristics of wastewater from plant.
3. Quality of the receiving waters.
4. Size of flow from treatment plant.
5. Type of degree of treatment.

Answer 22

1. Amount of flow in the receiving steam.
2. Characteristics of wastewater from plant.
3. Quality of the receiving waters.
4. Size of flow from treatment plant.
5. Type of degree of treatment.

Question 23

Multiple choice: What should an operator do after working an arithmetic problem involving the operator’s job?

1. Check calculations.
2. Continue to operator the plant without consideration of calculations.
3. Examine answer to see if it appears reasonable.
4. Have another operator check work before making any changes.
5. Immediately make any appropriate changes.

Answer 23

1. Check calculations.
2. Examine answer to see if it appears reasonable.
3. Have another operator check work before making any changes.

Question 24

Which of the following are objectives used by operators of wastewater treatment plants to operate their plants?

1. Maintain an effective preventive maintenance program
2. Meeting NPDES permit requirements.
3. Minimizing costs.
4. Minimizing odors to avoid nuisance complaints.
5. Removing wastes from the wastewater to protect the receiving waters.

Answer 24

All the answers.

1. Maintain an effective preventive maintenance program
2. Meeting NPDES permit requirements.
3. Minimizing costs.
4. Minimizing odors to avoid nuisance complaints.
5. Removing wastes from the wastewater to protect the receiving waters.

Question 25

An NPDES permit may specify which of the following items? 1. Acceptable range of pH values. 2. Frequency of collecting samples. 3. Minimum budget for plant O&M 4. Monthly average and maximum levels of suspended solids. 5. Virtually no substances toxic to organisms.

Answer 25

1. Acceptable range of pH values. 2. Frequency of collecting samples. 4. Monthly average and maximum levels of suspended solids. 5. Virtually no substances toxic to organisms.