Pa Wastewater Module 1 (Introduction To Wastewater Treatment)

Front 1

What are some examples of different interests various audiences may have?

Back 1

Officials of regulatory agencies or other operators would want to be provided with detailed

information on the operation of the plant. School classes would want to know only very basic

information. Public tours or tours of the news media may be interested in water quality, which will

help contribute to acceptance and support.

Front 2

What are some typical safety issues in a plant?

Back 2

Some typical safety issues include:

 Chlorine Safety (potentially toxic atmosphere)

 Confined space entry – Most common cause of death from an on-the job accident for

collection system operators is through asphyxiation.

 Explosions hazards – anaerobic digester producing methane gas

 Fall hazards

 Electrical Hazards

Front 3

True or False: Treatment plant operators are required to complete continuing education.

Back 3

True

Front 4

A process control decision is any action to maintain or change the ______ or _______of water being treated.

Back 4

A process control decision is any action to maintain or change the quality or quantity of water being treated.

Front 5

Which one of the following is a treatment plant operator NOT responsible for:

a. Plant tours

b. Process control decisions

c. Upgrading the electrical service panel

d. Collecting samples

Back 5

c. Upgrading the electrical service panel

Front 6

What are some examples of organic impurities from industrial contributors?

Back 6

Examples of organic impurities include:

 Chloroform from leather tanning operations and pharmaceuticals manufacturing

 Trichloroethylene from textile mills and adhesive manufacturing

 Phenols from pesticide manufacturing and from iron and steel manufacturing

 BOD and fats, oils, and greases from food processing industries

Front 7

A stream used for trout stocking is one example of a thermal sensitive stream where the stream

temperature needs to be regulated. Can anyone think of any other reasons to regulate the

temperature of discharges to the receiving stream?

Back 7

Additional reasons to regulate the temperature of discharges are:

 To prevent loss of dissolved oxygen (DO)––the amount of DO that can be dissolved into water

decreases as the temperature of the water increases, and

 To control undesirable aquatic growth such as algae, which grow faster at higher

temperatures.

Front 8

What are some communicable diseases that could be transmitted via untreated wastewater?

Back 8

Typhoid, cholera, dysentery, polio, hepatitis.

Front 9

Contaminants found in untreated wastewater may include: (Circle all that apply):

a. Pathogens

b. Ozone

c. Organic contaminants

d. Inorganic contaminants

Back 9

a. Pathogens

c. Organic contaminants

d. Inorganic contaminants

Front 10

A type of contaminant that always contains carbon and is derived from animals, plants or may be a

manufactured chemical compound is an:

a. Inorganic contaminant

b. Salt contaminant

c. Organic contaminant

d. Pathogen

Back 10

c. Organic contaminant

Front 11

Organic contaminants exert an oxygen demand, which is measured as:

Back 11

BOD

Front 12

Typical influent BOD to a wastewater plant is approximately:

a. 20 to 30 mg/L

b. 100 to 125 mg/L

c. 200 to 250 mg/L

d. 500 to 600 mg/L

Back 12

c. 200 to 250 mg/L

Front 13

Typical influent (untreated) total nitrogen concentration is approximately:

a. 0 to 5 mg/L

b. 30 to 50 mg/L

c. 100 to 125 mg/L

d. 300 to 350 mg/L

Back 13

b. 30 to 50 mg/L

Front 14

True or False: Total solids consist of dissolved solids and suspended solids.

Back 14

True

Front 15

Influent wastewater flow and temperature can increase suddenly due to which of the following:

a. Infiltration

b. Increased return activated sludge

c. Industrial waste discharges

d. Increased solids removal

Back 15

c. Industrial waste discharges

Front 16

Untreated wastewater discharge can create which of the following?

a. High chlorine levels in the receiving stream

b. Oxygen depletion in the receiving stream

c. Sludge and scum accumulations

d. Low odor production in the stream

Back 16

b. Oxygen depletion in the receiving stream

c. Sludge and scum accumulations

Front 17

Eutrophication can be defined as:

a. Lack of nutrients in a receiving stream due to chemical discharges

b. Excessive nutrient availability that results in overgrowth of aquatic plants and algae

c. Excessive growth of fish

d. Pleasing taste and odor in drinking water

Back 17

b. Excessive nutrient availability that results in overgrowth of aquatic plants and algae

Front 18

__________is the process of converting a waste to a form that resists change.

Back 18

Stabilization

Front 19

True or False: An increase in wastewater

temperature results in a decreased ability to retain dissolved oxygen.

Back 19

True. Dissolved oxygen in water is dependent on temperature.

Front 20

Important nutrients have natural “Nutrient Cycles” in the receiving stream and within the wastewater

treatment plant. Name at least 3 of these nutrients:

Back 20

Carbon

Hydrogen

Oxygen

Sulfur

Nitrogen

Phosporous

Front 21

Why should the operator be familiar with the wastewater collection and conveyance network?

Back 21

The operator should know the origin of wastes reaching the plant, the time it takes, and how the

wastes are transported (flow by gravity or by gravity and pumped). Such knowledge will help you

spot troubles and take corrective action.

Front 22

What is typically done with grit once it is removed from wastewater?

Back 22

Grit is usually taken to an approved sanitary landfill.

Front 23

Why is the Parshall Flume widely used for measuring wastewater flow? Why is the Weir not used

very frequently to measure influent?

Back 23

The parshall flume is widely used for measuring untreated wastewater flow because it creates no

obstructions to the flow of wastewater, which minimizes the chance for blockages or accumulations

that might affect the depth of flow and subsequently, the measured flow rate.

The weir is not used as frequently because solids may collect behind the weir, which could result in

inaccurate flow measurements. This collection of solids could also cause odors.

Front 24

Why is a secondary clarifier needed after a trickling filter, rotating biological contractor, or aeration

tank?

Back 24

To allow organisms in treated wastewater to be removed by settling.

Front 25

1. What are the three major components of a Wastewater System?

Back 25

1. Collection and Conveyance

2. Treatment

3. Disposal

Front 26

Name the three types of collection systems and briefly describe.

Back 26

1. Sanitary Sewer- collects commercial and household wastes.

2. Storm Sewer- Collects runoff from streets, land and roofs.

3. Combined Sewer- Collects sanitary and storm water.

Front 27

Gravity sewer system are sued when the slope is sufficient to produce __________ .

a. 1 ft/sec

b. 2 ft/sec

c. 3 ft/sec

d. 4 ft/sec

Back 27

b. 2 ft/sec

Front 28

______wastewater has a characteristic black color and is brought on by the action of anaerobic

bacteria.

Back 28

Septic

Front 29

True or False: In preliminary treatment, grit channel cleaning results in a flow velocity decrease through

the channel.

Back 29

True

Front 30

Which of following are flow control devices:

a. Weir

b. Serial Rod

c. Parshall Flume

d. Kennison Nozzle

Back 30

a. Weir

c. Parshall Flume

d. Kennison Nozzle

Front 31

In a clarifier, the sludge that forms at the bottom may be referred to as the:

a. Sludge cover

b. Sludge level

c. Sludge blanket

d. Waste sludge

Back 31

c. Sludge blanket

Front 32

What type of settling tank typically follows the biological treatment step

a. Primary clarifier

b. Secondary clarifier

c. Trickling filter

Back 32

b. Secondary clarifier

Front 33

True or False: During clarification, large amounts of sludge rising to the surface may indicate that not

enough sludge is being “wasted”.

Back 33

True

Front 34

Advanced (tertiary treatment) is primarily intended remove which two inorganic contaminants:

Back 34

a. Nitrogen

b. Phosphorous

Front 35

Describe two methods of effluent disposal.

Back 35

1. Stream discharge

2. Land disposal

Front 36

What are examples of conditions that cause violations?

Back 36

Conditions that cause violations:

 Overloading conditions that can lead to overflows, by-passes, or process upsets

 Mechanical equipment deficiencies

 Inadequate budget for maintenance or operation of the plant

Front 37

What are examples of tasks that would be candidates for a Standard Operating Procedure?

Back 37

Examples of tasks would be:

 Field measurement of pH or DO

 Calibrating field montoring instrumentation

 Rotation of duplicate pumping equipment to equalize wear, without changing pumping rates

Front 38

Preliminary Treatment

Back 38

Remove large debris by screening and degritting

Front 39

Primary Treatment

Back 39

Remove settleable solids

Front 40

Secondary Treatment

Back 40

Biological treatment that produces acceptable effluent

and/or Eliminate dissolved and nonsettleable/colloidal

organic material

Front 41

Solids Handling & Disposal

Back 41

Sludge stabilization, pathogen reduction, and land

application

Front 42

Waste Treatment Ponds

Back 42

Biological treatment that produces acceptable effluent

Front 43

Advanced/Tertiary

Treatment

Back 43

Reduce nutrient content to prevent algae growth

Front 44

Disinfection

Back 44

Inactivate pathogenic organisms