level 2

What is pressure head caused by?

a. water flow

b. water elevation

c. potential energy plus water velocity

d. potential energy plus kinetic energy

water elevation

What color should the piping be that contains reclaimed water?

a. orange

b. purple

c. yellow

d. red

purple

What is the term for the height to which a column of water will rise in a well?

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a. potentiometric surface

b. unconfined level

c. piezometric surface

d. groundwater level

piezometric surface

In general, what is the maximum practical lift of pumps?

a. 10 to 15 ft

b. 15 to 25 ft

c. 25 to 30 ft

d. 30 to 35 ft

15 to 25 ft

Which one of the following valves is best to use in throttling flow situations?

a. gate

b. butterfly

c. globe

d. ball

globe

Which one of the following devices is used to measure water depths in storage facilities?

a. transducer

b. Venturi meter

c. magnetic sensor

d. thermistor

transducer

The velocity in sanitary sewers is approximately

a. 1 foot per second (ft/s)

b. 2 ft/s

c. 3 ft/s

D. 3.5 ft/s

2 ft/s

The distance between manholes ranges from

a. 300 to 500 ft

b. 500 to 600 ft

c. 750 to 1,000 ft

d. 900 to 1,200 ft

300 to 500 ft

What should the flow velocity be through a grit channel?

a. 0.5 ft/s

b. 1.0 ft/s

c. 1.5 ft/s

d. 2.0 ft/s

1\.0 ft/s

Grit washers are used to

a. remove some of the organic matter

b. remove large pieces of wood

c. remove rags and eggshells

d. remove the odors

remove some of the organic matter

The most common flow-measuring device for wastewater is

a. Parshall flume

b. magnetic flowmeter

c. weir

d. Venturi meter

Parshall flume

The detention time for primary clarifiers usually has a range of

a. 1.5 to 2 hr

b. 4 to 5 hr

c. 3 to 7 hr

d. 5 to 12 hr

a. 1.5 to 2 hr

The effluent from which process is called mixed liquor?

a. secondary clarification

b. primary clarification

c. sludge drying bed or pond

d. activated sludge

activated sludge

Aerobic ponds usually range in depth from

a. 2 to 4 ft

b. 3 to 6 ft

c. 3 to 8 ft

d. 4 to 8 ft

3 to 6 ft

Anaerobic ponds usually range in depth from

a. 4 to 8 ft

b. 6 to 12 ft

c. 8 to 12 ft

d. 10 to 14 ft

8 to 12 ft

Another name for a waste stabilization pond is

a. raw wastewater lagoon

b. facultative pond

c. anaerobic pond

d. decomposition pond

raw wastewater lagoon

Typically, what average percent of total solids in domestic wastewater, both dissolved and suspended, are organics?

a. 20%

b. 25%

c. 38%

d. 50%

50%

Typically, what average percent of total solids in domestic wastewater, both dissolved and suspended, are inorganics?

a. 25%

b. 35%

c. 45%

d. 50%

50%

Approximately what percent of the dissolved solids in wastewater are inorganics?

a. 33%

b. 50%

c. 75%

d. 87%

87%

Approximately what percent of the dissolved solids in wastewater are organics?

a. 12%

b. 20%

c. 25%

d. 36%

12%

Which type of organisms would most probably be associated with moderate sludge age and effluent water quality?

a. stalked ciliates

b. free-swimming ciliates

c. amoebas

d. rotifers

b. free-swimming ciliates

Which type of organisms would most probably be associated with high suspended solids and biochemical oxygen demand (BOD)?

a. amoebas

b. stalked ciliates

c. free-swimming ciliates

d. rotifers

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a. amoebas

High suspended solids and BOD are most probably associated with which type of organisms?

a. stalked ciliates

b. rotifers

c. free-swimming ciliates

d. flagellates

d. flagellates

Which type of organism would most likely enhance the penetration of oxygen into the activated sludge?

a. rotifers

b. flagellates

c. amoebas

d. free-swimming ciliates

a. rotifers

Chlorine gas has a specific gravity of

a. 1.5 sp gr

b. 2.0 sp gr

c. 2.5 sp gr

d. 3.0 sp gr

c. 2.5 sp gr

Proper flow velocity through a grit channel is indicated when the grit being removed contains

a. no organics

b. a little organic material

c. about half the volume as the grit being removed

d. about the same volume as the grit being removed

b. a little organic material

Surface loading and detention time in a clarifier are directly related to

a. the amount of settleable solids

b. size of the sludge hopper

c. weir length

d. flow through the clarifier

d. flow through the clarifier

What is the expected range for the removal of settleable solids from a primary clarifier?

a. 80 to 90%

b. 85 to 90%

c. 90 to 95%

d. 95 to 99%

d. 95 to 99% hmm, sacramento book is 90-95

What condition will occur if sludge is not pumped out of primary clarifiers at regular intervals?

a. broken or mechanical failure of the flights

b. clogged pump(s) when the pumps come on

c. clarifier will become septic

d. sludge will clog the sludge removal pipe

c. clarifier will become septic

Secondary clarifiers are usually located after

a. the primary clarifier

b. an anaerobic digester

c. a biological process

d. preaeration

c. a biological process

Filter sloughings are a product of

a. biological action

b. chemical action

c. physical processes

d. chemical and physical processes

a. biological action

When one liquid is dissolved in another liquid it is called

a. a colloid

b. an emulsion

c. a compound

d. floc

b. an emulsion

.What is the optimum temperature for digester substances?

a. 86°F

b. 88°F

c. 90°F

d. 95°F

90°F

Which one of the following types of wastewater ponds listed below is not classified like the other three?

a. polishing pond

b. oxidation pond

c. aerobic pond

d. raw sewage stabilization pond

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aerobic pond

What type of pond would receive wastewater from a secondary treatment system?

a. aerated pond

b. oxidation pond

c. stabilization pond

d. polishing pond

d. polishing pond

The color of the biofilm on a rotating biological contactor undergoing nitrification would appear

a. grayish green

b. grayish brown

c. greenish brown

d. reddish brown to golden

d. reddish brown to golden

The color of the biofilm on a rotating biological contactor that has high sulfur concentrations would appear

a. chalky white

b. yellowish green

c. yellow

d. golden brown

chalky white

Rotating biological contactors have all the following advantages except:

a. high sludge production

b. they can handle a large range of flows

c. power requirements are low

d. low operating costs, as they are easy to run

high sludge production

A wastewater plant has a train of three rotating biological contactor (RBC) units. The color of the first RBC is _______; the color of the second RBC is _______; and the color of the third RBC is _______.

a. (1) yellowish green; (2) green; (3) very dark green to gray

b. (1) green; (2) green; (3) golden green

c. (1) gray; (2) reddish brown; (3) reddish brown

d. (1) yellowish green; (2) green; (3) golden brown

(1) gray; (2) reddish brown; (3) reddish brown

Which one of the following activated sludge process modifications is very sensitive to bulking?

a. conventional modification

b. extended aeration activated sludge

c. complete mix aeration

d. pure oxygen

conventional modification

Which modified activated sludge process does not require primary treatment?

a. complete mix aeration

b. contact stabilization

c. tapered aeration

d. step aeration

contact stabilization

Primary treatment is not required in which modified activated sludge process?

a. step aeration

b. complete mix aeration

c. tapered aeration

d. extended aeration activated sludge

extended aeration activation sludge

Mixed liquor is a combination of the following mixture:

a. activated sludge with primary effluent mixed in a pond or clarifier

b. raw water with primary effluent and return sludge mixed in an aeration tank

c. activated sludge in an aeration tank mixed with primary effluent and return sludge or raw wastewater

d. activated sludge mixed with raw wastewat**e**r in a clarifier or aeration tank

activated sludge in an aeration tank mixed with primary effluent and return sludge or raw wastewater

In a small package wastewater treatment plant, the operator should try to keep the dissolved oxygen in the aeration tank at approximately

a. 1.0 mg/L

b. 2.0 mg/L

c. 3.0 mg/L

d. 4.0 mg/L

2\.0 mg/L

How much of the solids should be wasted each week in the summer from a package wastewater treatment plant for the best water quality?

a. 5%

b. 10%

c. 20%

d. 25%

5%

At what concentration level should dissolved oxygen be maintained during the initial startup of an oxidation ditch?

a. 0.5 mg/L

b. 1.0 mg/L

c. 1.5 mg/L

d. 2.0 mg/L

2\.0 mg/L

What should be the color of an oxidation ditch that is working properly?

a. light yellow to tan

b. tan to light brown

c. light brown to medium brown

d. medium brown to dark brown

medium brown to dark brown

Which one of the following is the least important in the successful operation of an activated sludge plant?

a. BOD

b. food entering the process (the solids)

c. sludge age

d. organisms available to treat the wastes

BOD

What is the critical factor in any method to control the aeration tank?

a. BOD

b. F/M (food-to-microorganism) ratio

c. COD (chemical oxygen demand

d. DO (dissolved oxygen)

F/M (food-to-microorganism) ratio

What is the most accurate measure of the organisms present in an aerator for treating incoming wastes?

a. BOD

b. MLSS (mixed liquor suspended solids)

c. MLVSS (mixed liquor volatile suspended solids)

d. COD

MLVSS (mixed liquor volatile suspended solids)

Most algae are in the

a. plant kingdom

b. animal kingdom

c. Monera kingdom

d. Protista kingdom

Protista kingdom

Bacteria are in the

a. plant kingdom

b. animal kingdom

c. Monera kingdom

d. Protista kingdom

Monera kingdom

Grease should be cleaned from walkways with a stiff brush and

a. detergent

b. bleach

c. trisodium phosphate

d. phosphate-free surfactant

trisodium phosphate

Which one of the following types of substances is not soluble in water and has the potential of creating explosive conditions?

a. oils and greases

b. toxic gases

c. flammable oils

d. organic toxicants

flammable oils

Which one of the following types of substances can cause obstructions in the sewer system and may cause anaerobic decomposition where the substances accumulate?

a. heavy metals

b. oils and greases

c. flammable oils

d. settleable solids

. settleable solids

Which one of the following types of substances is corrosive and may interfere with biological treatment?

a. organic toxicants

b. cyanides

c. acids and alkalies

d. heavy metals

acids and alkalies

Which one of the following types of substances can be toxic to wastewater plants using biological systems and may adversely affect potable water supplies downstream?

a. heavy metals

b. toxic gases

c. cyanides

d. acids and alkalies

heavy metals

Where would toxicants least likely cause a problem for a wastewater treatment plant?

a. clarifier

b. trickling filter

c. sludge digester

d. activated sludge

clarifier

If an activated sludge plant is hit with a high organic load, what will most likely occur in the aeration tank?

a. BOD will increase

b. there will be a significant decrease in DO

c. a more turbid effluent

d. effluent will exhibit floc carry-over

there will be a significant decrease in DO

In the following list, which is the least important nutrient in wastewater treatment for microorganisms to reproduce?

a. potassium

b. nitrogen

carbon in organic matter

d. phosphorus

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potassium

Adequate BOD/nitrogen/phosphorus ratio for microorganisms to grow is usually

a. 100:2:1, respectively

b. 100:5:1, respectively

c. 100:10:3, respectively

d. 100:12:5, respectively

100:5:1, respectively

Humus sludge is biomass from

a. trickling filters

b. primary clarifiers

c. secondary clarifiers

d. primary digesters

trickling filters

Excessive slime growths on a trickling filter may cause a condition on the filter called

a. overload

b. ponding

c. clogging

d. sloughing

ponding (voids become plugged by stuff)

Another name for slime growth is

a. slag

b. zoogleal film

c. algal mat

d. humus

zoogleal film

It is not recommended to start up trickling filters in the _______ because bacteria are most often dormant at this time.

a. late fall, winter, and early spring

b. late fall and winter

c. winter and early spring

d. winter

winter

When the influent load to a wastewater treatment plant changes rapidly, the best test for control purposes is

a. total solids

b. DO

c. BOD

d. COD

COD

A problem with odors from trickling filters may be solved by

a. reducing the number of weeds

b. using masking agents

c. applying chlorine

d. flooding the filter

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using masking agents

What can be done to the trickling filter to solve high effluent suspended solids?

a. flush out distributor arms

b. decrease recirculation

c. reduce the number of weeds

d. flood the filter

decrease recirculation?? idk about this

Approximately how much surface area of a rotating biological contactor is immersed in the wastewater?

a. 40%

b. 45%

c. 50%

d. 60%

40%

How many stages are usually present in the rotating biological contactor process?

a. three stages

b. four stages

c. six stages

d. eight stages

four stages

Rotating biological contactors are adversely affected by temperatures below

a. 40°F

b. 43°F

c. 48°F

d. 55°F

55°F

How often should the oil be changed in the speed reducer of a rotating biological contactor?

a. every 2 months

b. every 3 months

c. every 6 months

d. every 12 months

every 6 months

How often should the motor bearings be greased in a rotating biological contactor unit?

a. every 2 months

b. every 3 months

c. every 6 months

d. every 12 months

every 12 months

How often should the mainshaft bearings be greased in a rotating biological contactor unit?

a. every week

b. every month

c. every 3 months

d. every 6 months

every week

How often should the drive bearings be greased in a rotating biological contactor unit?

a. every week

b. every month

c. every 3 months

d. every 6 months

every week

How often should the oil in the chain casing be changed RBC?

a. every 2 months

b. every 3 months

c. every 6 months

d. every 12 months

every 3 months

Ponds used in series after a trickling filter are sometimes called

a. polishing ponds

b. oxidation ponds

c. secondary treatment ponds

d. tertiary treatment ponds

polishing ponds

A pond that contains algae and requires the use of compressors is classified as

a. an anaerobic pond

b. an aerobic pond

c. a facultative pond

d. an oxidation pond

an aerobic pond

A pond that depends on fermentation, is odorous, and is used mainly for processing industrial wastes is classified as

a. an anaerobic pond

b. an aerobic pond

c. a facultative pond

d. a oxidation pond

. an anaerobic pond

A pond that contains oxygen in its upper layers and lacks oxygen in the bottom layer is classified as

a. an anaerobic pond

b. an aerobic pond

c. a facultative pond

d. an oxidation pond

a facultative pond

When is the pH in a waste pond the lowest?

a. sunrise

b. sunset

c. around noon

d. around 4:00 pm

sunrise

When is the pH in a waste pond the highest?

a. sunrise

b. sunset

c. around noon

d. around 4:00 pm

around 4:00 pm

When is the dissolved oxygen in a waste pond the highest?

a. sunrise

b. sunset

c. around noon

d. around 4:00 pm

around 4:00 pm

Regarding waste pond lab sampling, which one of the following parameters is sampled at the influent of the pond?

a. pH

b. BOD

c. DO

d. temperature

. BOD

How far out from the water’s edge should waste pond samples be collected?

a. 6 ft

b. 8 ft

c. 10 ft

d. 15 ft

8 ft

At what depth should samples be collected from a waste pond?

a. 1 ft

b. 1.5 ft

c. 2.0 ft

d. 2.5 ft

1 ft

The recommended minimum depth for a waste pond is

a. 2.0 ft

b. 2.5 ft

c. 3.0 ft

d. 3.5 ft

3\.0 ft

Saprophytic microorganisms are also called

a. acid formers

b. methane fermenter

s c. alcohol fermenters

d. facultative fermenters

acid formers

Microorganisms that are methane fermenters will only produce in the pH range of

a. 5.8 to 6.5

b. 6.1 to 7.0

c. 6.6 to 7.6

d. 6.8 to 8.3

6\.6 to 7.6

Digestion is working properly if the volatile solids content of the raw sludge has been reduced by

a. 40 to 60%

b. 50 to 60%

c. 55 to 65%

d. 60 to 75%

50 to 60%

An anaerobic sludge digester should be operated such that

a. acid formation is greater than methane formation

b. acid formation is equal to methane formation

c. acid formation is less than methane formation

d. acid formation is less than alkaline formation

acid formation is equal to methane formation

The most common imbalance in the operation of an anaerobic sludge digester is

a. excess acid fermentation

b. excess methane fermentation

c. insufficient mixing

d. pH becomes too alkaline

excess acid fermentation

The most important factor in the high-rate process of anaerobic digestion is

a. DO

b. COD

c. F/M ratio

d. mixing

mixing

Operators should, as a rule, never change the temperature in an anaerobic digester by more than

a. 1°F/day

b. 2°F/day

c. 3°F/day

d. 4°F/day

1°F/day

What is the optimum temperature range of mesophilic bacteria in anaerobic digestion?

a. 68 to 80°F

b. 80 to 100°F

c. 85 to 100°F

d. 88 to 105°F

85 to 100°F

What is the purpose of a draft tube in an anaerobic sludge digester?

a. removes methane gas from the digester tank

b. directs raw and digested sludge mixture to a heating area

c. removes sludge to be used as seed sludge

d. collects supernatant for moving to the primary clarifier or headworks

directs raw and digested sludge mixture to a heating area

How often should the liquid level be checked on a digester to prevent overfilling?

a. once/day

b. two times/day

c. three times/day

d. four times/day

once/day

Typically, an anaerobic digester will produce about 30% to 35% by volume of which particular gas from the following list?

a. CO2

b. H2

CH4

d. N2

CO2

How often should flame arresters be serviced on anaerobic digesters?

a. every 3 months

b. every 6 months

c. once/year

d. every 2 years

every 3 months

How often should the thermal valves be dismantled for service?

a. every 3 months

b. every 6 months

c. once/year

d. every 2 years

once/year