Chapter 2- Why Treat Wastes?

Question 1

True or false

All organic materials have one thing in common— they all contain basic minerals.

Answer 1

False.
Pg 18

They all contain carbon.

Question 2

True or false

Most living creatures need oxygen to survive, including fish and other aquatic life.

Answer 2

True.

Pg 19

Question 3

True or false

Initial efforts to control human wastes evolved from the need to prevent the spread of diseases.

Answer 3

True.

Pg 20

Question 4

True or false

The bacteria that grow in the intestinal tract of diseased humans find the environment in the wastewater treatment plant or receiving waters favorable for their growth and reproduction.

Answer 4

False.

Pg 20

Question 5

True or false

One of the primary functions of a treatment plant is the removal of solids from wastewater.

Answer 5

True.

Pg 21

Question 6

True or false

Operators try to kill or inactivate pathogenic organisms by disinfection.

Answer 6

True.

Pg 6

Question 7

True or false

The weight of non-settleable solids may be calculated by subtracting the weight of dissolved and total solids from the weight of settleable solids.

Answer 7

False.
Pg 21

You may calculate the weight of non-settleable solids by subtracting the weight of DISSOLVED and SETTLEABLE solids from the weight of TOTAL solids.

Question 8

True or false

The organic portion of the total solids can be very harmful to receiving waters.

Answer 8

True.

Pg 21

Question 9

True or false

Operators should use a standard method for the measurement and evaluation of floatable solids.

Answer 9

True. ?
Pg 21

There is no standard method for the measurement and evaluation of floatable solids.

Question 10

True or false

Nutrient cycles are very complex and involve chemical changes in living organisms.

Answer 10

True.

Pg 23

Question 11

What is the definition of pollution?

Answer 11

The impairment (reduction) of water quality by agricultural, domestic, or industrial wastes (including thermal and radioactive wastes) to a degree that the natural water quality is changed to hinder any beneficial use of the water or render it offensive to the senses of sight, taste, or smell or when sufficient amounts of wastes create or pose a potential threat to human health or the environment.
Pg 16

Question 12

What is organic waste?

Answer 12

Waste material that may come from animal or plant sources. Natural organic wastes generally can be consumed by bacteria and other small organisms. Manufactured or synthetic organic wastes from metal finishing, chemical manufacturing, and petroleum industries may not normally be consumed by bacteria and other organisms.
Pg 16, 18

Question 13

What is Inorganic waste?

Answer 13

Waste material such as sand, salt, iron, calcium, and other mineral materials that are only slightly affected by the action of organisms. Inorganic wastes are chemical substances of mineral origin.
Pg 16, 18

Question 14

What happens to fish in receiving waters when bacteria use the entire supply of oxygen from the stream faster that’s it can be replenished by natural diffusion from the atmosphere?

Answer 14

When this happens, fish and most other in the stream that require dissolved oxygen die.
Pg 19

Question 15

The stabilization of a waste means which of the following?

Answer 15

Conversion to a form that resists change. Organic material is stabilized by bacteria that convert the material to gases and other relatively inert substances. Stabilized material generally will not give off obnoxious odors.
Pg 19

Question 16

Many serious outbreaks of communicable diseases have been traced to which problem?

Answer 16

Direct contamination of drinking water or food supplies by the body wastes from a human disease carrier.
Pg 20

Question 17

What is an operator’s best defense against infections and diseases?

Answer 17

Good personal hygiene.

Pg 20

Question 18

What is the objection to treated wastewaters containing nutrients?

Answer 18

Nutrients are capable of encouraging excess algae and plant growth in receiving waters.
Pg 21

Question 19

Why are floatable solids undesirable in the plant effluent?

Answer 19

Because the sight of floatables in receiving waters indicates the presence of inadequately treated wastewater.
Pg 21

Question 20

Why are ammonia and hydrogen sulfide undesirable in receiving waters?

Answer 20

They are odorous gases that make water look terrible.

Pg 23

Question 21

Substantial amounts of organic industrial waste come from which industries?

Answer 21

Dairy processing, meat packing, tanning, vegetable and fruit packing.
Pg 18

Question 22

Waste discharges may contain what types of toxic substances?

Answer 22

Heavy metals (lead, mercury, cadmium, and chromium) cyanide and chlorine residual.
Pg 20

Question 23

Which substances are objectionable in treated wastewater discharges?

Answer 23

Color producing substances, highly acid or alkaline (basic) substances, taste and odor producing or toxic substances.
Pg 20

Question 24

Whether any problems are caused by the discharge of treated wastewater in the receiving waters depends on which factors?

Answer 24

1. Amount of flow in the receiving stream or volume of receiving lake that can be used for dilution.
2. Quality of the receiving waters.
3. Size of flow from the treatment plant.
4. Type or degree of treatment.
5. Uses of the receiving waters.
   Pg 22

Question 25

Why do operators need to know how to control nutrient cycles?

Answer 25

To control odors, treat wastes, and to protect receiving waters.
Pg 23

Question 26

Vocab

Aerobic bacteria

Answer 26

Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration, namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules, cannot be used for respiration by aerobic bacteria.
Pg 15