Abc Water Operator 3

Front 1

What is the primary drawback for facilities that use ultraviolet light to disinfect water?

Back 1

There is a potential for the light bulbs to be coated with light-obscuring material, preventing the UV light from killing microorganisms.

Front 2

Potassium permanganate is most effective in __________.

Back 2

Removing Iron.

Front 3

Chlorine is advantageous over chloramines in that chlorine _________.

Back 3

is a much stronger oxidant.

Front 4

Which oxidant has the potential of producing the Chlorate Ion, CIO3 by-products?

Back 4

Chlorine dioxide

Front 5

How thick should the layer of sodium fluoride crystals be maintained in a saturator tank for flows of less than 100 gpm?

Back 5

6 inches

Front 6

How much alkalinity as CaCO3 will dry-basis alum consume?

Back 6

0.5 mg/L

Front 7

Natural zeolites used for softening that have become exhausted with use are regenerated by immersing them in a strong solution of which chemical?

Back 7

NaCI

Front 8

The zeta potential on a particular sample of water is -2. The degree of coagulation is best described as ________.

Back 8

Excellent.

Front 9

What is a disadvantage of using static mixers?

Back 9

They increase head loss.

Front 10

What is the usual effective pH range of iron salt coagulants?

Back 10

3.5 to 9.0

Front 11

What determines whether or not colloidal-sized particles in suspension repel each other, stay in suspension, or agglomerate and eventually settle?

Back 11

Magnitude of the charges.

Front 12

If the sludge in a sedimentation basin becomes too thick, what could happen?

Back 12

Solids can become resuspended or taste and odors can develop.

Front 13

In basins using tube and plate settlers, what parameter must be much better that conventional treatment basins?

Back 13

Floc must have good settling characteristics.

Front 14

What type of sedimentation basin have the flow of water admitted at an angle?

Back 14

Spiral-flow basins

Front 15

At what minimum angle must self-cleaning tube settlers be placed?

Back 15

50 degrees

Front 16

If crustaceans have clogged the water treatment plant's filters, what is the most probable solution?

Back 16

Use a disinfectant that targets the specific organisms in question.

Front 17

What organism can escape coagulation and thus pass through a granular filter?

Back 17

Cryptosporidium

Front 18

Reverse osmosis membranes will compact faster with ________?

Back 18

Higher pressure.

Front 19

What would immediately occur if newly installed manganese greensand was not skimmed of the fines after backwashing and stratification steps were completed?

Back 19

Shorter filter runs.

Front 20

When a filter is operated at normal flow rates, its ability to trap flocculated particles in suspension is a function of ________?

Back 20

Media depth and media size.

Front 21

What is the total concentration of dissolved solids in the wastewater from the regeneration of ion exchange units?

Back 21

35,000 to 45,000 mg/L

Front 22

What is the usual range of percent sludge solids, if the sludge is allowed to accumulate and compact at the bottom of a sedimentation basin?

Back 22

2-4%

Front 23

What should be determined first before an in-ground sedimentation tank is drained?

Back 23

The water table level.

Front 24

What sludge dewatering process is best for alum sludges (which are difficult to dewater) when the cakes are very dry, filtrate is clear, and solids capture is very high?

Back 24

Filter press

Front 25

What sludge dewatering process requires a precoat of diatomaceous earth and its use has declined due to other newer methods?

Back 25

Vacuum filters

Front 26

It is impossible to produce waters with a hardness of less than ____ when using the lime-soda ash process.

Back 26

25 mg/L

Front 27

When added to water for softening purposes, soda ash will do what?

Back 27

Disinfect the water and kill the vast majority of protozoans, viruses, bacteria, and other multicellular organisms.

Front 28

Magnetic ion exchange resin has been developed to remove ___________.

Back 28

Total organic carbon.

Front 29

Approximately how much carbon is lost during the reactivation process for granular activated carbon?

Back 29

5%

Front 30

What is the most advantageous application point for powdered activated carbon?

Back 30

Raw water intake.

Front 31

Water that is to be analyzed for inorganic metals should be acidified with ____________.

Back 31

Concentrated nitric acid.

Front 32

A solution used to determine the concentration of another solution is called a ______________.

Back 32

standardized solution.

Front 33

What method would you use to concentrate and retrieve low numbers of bacteria from a large quantity of water?

Back 33

Membrane filtration

Front 34

A typical coliform colony in the membrane filter method has what characteristics?

Back 34

Pink to dark red with green metallic surface sheen

Front 35

In the presumptive phase of the Most Probable Number Test, how long does it take for the coliforms to produce gas?

Back 35

24-48 hours

Front 36

If a water system collects at least 40 samples per month for the analyses of total coliforms, which percent of total coliform positive samples are acceptable for the system to remain in compliance with the maximum contaminant level for total coliforms?

Back 36

No more than 5%

Front 37

Water systems are required to achieve at least _______ removal and/or inactivation of viruses between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer.

Back 37

4 log

Front 38

Where are the sampling points located for required sampling of organics (except trihalomethanes) in a community water system?

Back 38

Entry points into the distribution system

Front 39

Where are the sampling point(s) located for required sampling of natural radionuclides in a community water system?

Back 39

Each entry point to the system

Front 40

Continuous chlorine residual monitoring is required where the water enters the distribution system under the Surface Water Treatment Rule when the _____________.

Back 40

population served is >3300 people

Front 41

A single chlorine cylinder is delivering 48 lb/d of chlorine to the water process, causing the cylinder to form a little frost. What would be the best solution to this problem?

Back 41

Add another cylinder and feed from both.

Front 42

The pressure-reducing and shutoff valve on a vaporizer will shut off when there is a/an ______________.

Back 42

loss of electrical power.

Front 43

Particle counters use the principle of light __________.

Back 43

blockage

Front 44

How much time does it usually take to slake lime in the detention-time lime slaker?

Back 44

20 - 30 minutes

Front 45

At which temperature should the slaking process be maintained?

Back 45

160 degrees F or higher

Front 46

Water treatment personnel should only use self-contained breathing apparatus equipment that has been approved by ________.

Back 46

The National Institute of Occupational Safety and Health (NIOSH)

Front 47

If a substantial chlorine leak incident occurs, which agency should be called for actual hands-on assistance?

Back 47

The Chemical Transportation Emergency Center

Front 48

In regards to safety, wet activated carbon will remove __________ from the air.

Back 48

Oxygen

Front 49

An employee's average airborne exposure in any 8-hour shift in a 40-hour workweek that should not be exceeded is called _____________.

Back 49

Time-Weighted Average (TWA)

Front 50

Sites are required to do a site assessment under the process safety management (PSM) regulations (OSSA) if the facility in a single process has more than how many pounds of chlorine?

Back 50

1,500 lbs

Front 51

When water freezes it expands by _________ of its original volume.

Back 51

one-ninth

Front 52

Which type of polar bonds are between the hydrogen atoms and the oxygen atom in water?

Back 52

Covalent

Front 53

Which would be the most probable solution to control algae in the source water if the algae were clogging filters at the water plant?

Back 53

Control nutrients

Front 54

Total dissolved minerals in rainwater are typically close to _________.

Back 54

10.00 mg/L

Front 55

Because manganese is only slightly soluble, it is rarely found in surface waters above a concentration of ___________.

Back 55

1.0 mg/L