C1 Ops & Maint - C. Sedimentation

Question 1

D. Filtration

Sedimentation is improved by:

A. Short-circuting

B. Reducing the detention poeiod in the basin

C. Uniform, horizontal, low velocity flow across the basin

D. A thick sludge build up st the bottom of the basin

Answer 1

C. Uniform, horizontal, low velocity flow across the basin

Question 2

D. Filtration

What is the calm area within a settling basin, necessaryfor suspended materials to settle:

A. Inlet zone

B. Outlet zone

C. Settling zone

D. Sludge zone

Answer 2

C. Settling zone

Question 3

D. Filtration

Over a period of time sludge accumulation in settling basins will usualy:

A. Result in high levels of nitrates

B. Cause alum leaching

C. Result in tastes and odors

D. Reduce the flow in the rate in the basin

Answer 3

C. Result in tastes and odors

Question 4

D. Filtration

Normal operation if a sedimentation basin would include monitoring which of the following:

A. Turbidity into and out of basin and temperature.

B. Floc paddle speed and floc cary over.

C. Turbidity out of filters and contact time.

D. Temperature and alkilinity.

Answer 4

A. Turbidity into and out of basin and temperature.

Question 5

D. Filtration

5. What happens in a treatment plant when the flow is increased?

A. High

Question 6

D. Filtration

Sample bottle/bag should be filled as follows:

A. Just at the fill line.

B.

C. As needed.

D. About one inch from the top.

E. A, B & C

D. B & D

Answer 6

F. B (Just above the fill line) & D (About one inch from the top)

Question 7

D. Filtration

Sample bottles need to be __________ by the lab & _____ for ____.

Answer 7

Sample bottles need to be sterilized by the lab & ready for use.

sterilized

ready

use

Question 8

D. Filtration

Sample bottles have ______ ___________ in them to neutralize the ________.

Answer 8

Sample bottles have Sodium Thiosulfate in them to neutralize the Chlorine.

Sodium

Thiosulfate

Chlorine

Question 9

D. Filtration

TRUE or FALSE

The purpose of the sedimentation process is to remove suspended solids that are denser than the water and reduce the load on the filters.

Answer 9

TRUE

Question 10

C. Sedimentation / D. Filtration

The term used to express the filtration rate of a filter is:

A. Gallons

B. MGD/CF

C. gpm/ft²

D. CFS

Answer 10

C. gpm/ft²

Question 11

D. Filtration

Coagulation and sedimentation alone cannot remove all of the turbidity and suspended matter in raw water.

The final step in the removal of suspended matter in water is:

A. Chlorination

B. Sterilization

C. Flocculation

D. Filtration

Answer 11

D. Filtration

Question 12

D. Filtration

Filters in a water treatment process are primarily for removing or reducing:

A. Color

B. Tastes and odors

C. Carbon dioxide

D. Turbidity

Answer 12

D. Turbidity

Question 13

D. Filtration

Which of the following is the most important mechanism involved in the filtration process?

A. Biological action

B. Straining

C. Adsorption

D. Sedimentation

Answer 13

C. Adsorption

Question 14

D. Filtration

What is the purpose of the underdrain system on a treatment plant filter?

A. To diperse surface wash flows evenly across the filter

B. To evenly collect filtered water and disperse backwash water

C. To prevent a cross cronnection from the clearwell to the sedimentation basin

D. To increase the flow rater through the filter

Answer 14

B. To evenly collect filtered water and disperse backwash water

Question 15

D. Filtration

The common types of underdrain systems include the following:

A. Pipe lateral collectors, perforated tile bottoms, “Wheeler” bottoms< porous plate bottoms, and false-floor (Be familiar with all of these tupe of underdrain systems)

Answer 15

A. Pipe lateral collectors, perforated tile bottoms, “Wheeler” bottoms< porous plate bottoms, and false-floor (Be familiar with all of these tupe of underdrain systems)

Question 16

D. Filtration

In a coventional water filtration plant, the filter surface wash system is designed to prevent:

A. Air binding

B. Coal and sand loss

C. Break through

D. Mud balls

Answer 16

D. Mud balls

Question 17

D. Filtration

What is the most important water quality indicator used to monitor the filtration process?

A. Effluent turbidity

B. pH

C.Chlorine residual

D. Backwash rate

Answer 17

A. Effluent turbidity

Question 18

D. Filtration

Which of the following could cause short filter runs?

A. Overdosing of filter aid chemicals

B. Underdosing of filter aid chemicals

C. Low water temperatue

D. Low filtration rate

Answer 18

A. Overdosing of filter aid chemicals

Question 19

D. Filtration

What valve is in the open position during the backwash mode of a gravity type filter?

A. Influent valve

B. Drain valve

C. Effluent valve

D. None of the above

Answer 19

B. Drain valve

Question 20

D. Filtration

TRUE or FALSE

Gravity type rapid sand filters use an underdrain system that serves to support the filter medium, collect filtered water and distribute backwash water.

Answer 20

TRUE