Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

WW3-BurnsBook > Define > Flashcards

Define Flashcards

1
Q

Define SVI

A

The volume in milliliter (mL) occupied by one gram (g) of activated sludge mixed liquor after 30 minutes of settling.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

For an Activated sludge plant to be considered operating well. It will have an SVI range of?

A

80-120mL/g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens when the SVI goes gown?

A

Settling too fast and get pin flock which can go through the filters.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens when the SVI is too high. ?

A

The sludge isn’t settling well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

This chemical is frequently used to raise the pH of either wastewater or provide alkalinity for “sour” anaerobic digester.

A

Lime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Hydrated Lime

A

Calcium hydroxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Chemical used as a flocculent to improve suspended solids removal in a primary clarifier.

A

Ferric chloride.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Chemical added to anaerobic digesters to control the concentration of sulfur (Hydrogen Sulfide) in the digester gas.

A

Ferrous chloride.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Chemical used primarily as a coagulant in CEPT and to precipitate phosphorous in primary, secondary or tertiary treatment.

A

Aluminum sulfate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Also known as “Bioxide”. Commonly added in collection systems or at the influent structure in order to reduce or eliminate the production of hydrogen sulfide.

A

Calcium Nitrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

This chemical is an alkaline liquid solution commonly called “bleach”. 14% chlorine.

A

Sodium hypochlorite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

White crystalline material which contains approximately 70% available chlorine. Used in small scales. Due to high costs.

A

Calcium Hypochlorite.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

DAFT operational controls

A

Air/solids ratio - provides enough air to float the solids influent to the unit.
Range: .03-.05 lb air/lb TS

Solids loading. 3-5 lb TSS/hr•ft2
Typical range. 1-2 lb TSS/ he •ft2

Sludge Conditioning. - polymer added. 5-15 lb dry polymer/ton of TSS

Flight speed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Belt Filter Press (BFP) operational controls

A

Belt speed: 2-5 feet/min.

Ideal is slowest possible without causing “washout”.

Hydraulic Loading: flow rate applied to the belt per foot of belt width.
Recommended: 10-25 gal/min •ft

Sludge conditioning. : polymer necessary.

Feed sludge: primary only.

Belt tension: increased tension = more water being squeezed from the cake. (Higher TSS%).

Belt porosity: proper cleaning and tension.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

BFP solid washout problem. What’s the cause and the corrective steps. ?

A

Cause: insufficient polymer
Hydraulic loading too high
Belt speed too low
Belt binding.

Solutions :
Increase polymer
Lower fees rate
Increase belt speed 
Increase washwater flow.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

BFP Poor filtrate problem.

A

Cause: solids washout
High Belt Porosity

Solutions decrease belt tension. 
Properly wash belt 
Increase belt speed. 
Lower fees rate
Increase polymer
17
Q

BFP wet cake problem.

Cause and solution.

A

Cause
Belt speed too high
Belt tension too low

Solution.
Rescue belt speed.
Increase belt tension.

18
Q

Centrifuge operational controls.

A

Bowl speed:
Typically bowl turns 800-2,800 rpm producing 500-3,000 “Gs”
The higher the speed the dryer the cake.

Differential Scroll Speed.
Controls how fast cake is moved out of the bowl.
Higher differential = wetter cake

Pool Depth.
Greater pool depth reduces the time solids spend in the beach resulting in wetter cake.

Sludge Conditioning
Add appropriate amount of polymer.

Feed sludge:

19
Q

Gravity Thickener operational controls:

A

Sludge blanket thickness :
5-8 feet thick.

SVR - Sludge Volume Ratio
The detention time of solids in the thickener

Feed sludge: separated primary with secondary.

Temperature: cooler temps

Sludge age: with high-MCRT

Hydraulics loading.
Primary - 400-800 gal/d •ft2

Solids loading:

Primary sludge: 20-30 lbTS(S)/d•ft2
Trickling filter: 8-10  lbTS(S)/d•ft2
WAS.             : 5-8  lbTS(S)/d•ft2
Primary sludge+trickling filter humus:
             10-20  lbTS(S)/d•ft2
Primary sludge + WAS : 
              6-12  lbTS(S)/d•ft2
20
Q

Types of ponds

A

Stabilization
Oxidation
Polishing

21
Q

Waste treated in a stabilization pond?

A

Raw

22
Q

Waste water treated in an Oxidation pond?

A

Primary effluent

23
Q

What type of wastewater is treated in a polishing pond?

A

Secondary effluent.

24
Q

Pond that has an aerobic and anaerobic layer.

A

Stabilization. Or called facultative.

WW3-BurnsBook (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions