Wastewater Treatment Study Guide

Front 1

When water comes into a unit or tank?

Back 1

Influent

Front 2

When water leaves a unit or tank?

Back 2

Effluent

Front 3

Where does effluent go after treatment?

Back 3

Receiving water

Front 4

B.O.D.

(Define)

Back 4

Biochemical Oxygen Demand.

"Strength" of the wastewater.

Front 5

C.O.D.

(Define)

Back 5

Chemical Oxygen Demand

Front 6

BOD Test

Back 6

Five days at 20*C

Front 7

Samples should be stored at what Temp?

Back 7

4*C

Front 8

TSS

Back 8

Total Suspended Solids

Front 9

Examples of waterborne diseases

Back 9

Typhoid, Cholera, Dysentery, and Hep

Front 10

Waster water is __% Solids and ___% water?

Back 10

0.1% Solids

99.9 Water

Front 11

What percentage of solids are dissolved and suspended?

Back 11

80% Dissolved

20% Suspended

Front 12

Organic materials contain?

Back 12

Carbon

Front 13

Examples of Inorganic Material

Back 13

Sand, egg shell, Metals

Front 14

THREE types of Preliminary Treatment (SSG):

Back 14

Screening

Shredding

Grit Chamber

Front 15

Bar Screen v Bar Rack

Back 15

Bar Screen= 3/8-2in space

Bar Rack = 3-4in gap

Front 16

How are screenings properly disposed of?

Back 16

Burning or Burial

Front 17

How is Grit properly disposed?

Back 17

Burial at a properly permitted facility

Front 18

Two ways to measure flow/use?

Back 18

Flume or a Weir

Front 19

Self-Scouring velocity in gravity sewer:

Back 19

2 fps

Front 20

Grit Chambers ideal water velocity:

Back 20

1 fps (0.7-1.4 fps)

Front 21

Typical Clarifier velocity range:

Back 21

1-2 fps

Front 22

Primary Treatment removes ________ and _____?

Back 22

Settable and Suspended

Front 23

Primary Treatment is normally a Physical or Biological process?

Back 23

Physical

Front 24

Primary Clarifier Detention Time

Back 24

1-2 Hours

Front 25

Secondary Clarifier Detention Time

Back 25

2-3 Hours

Front 26

Primary sludge is usually ____ dense than secondary and ____ in color.

Back 26

More

Dark

Front 27

Secondary sludge is usually ____ dense than primary and is _____ in color.

Back 27

Less

Lighter

Front 28

Secondary clarifiers are always required to follow a secondary treatment process in order to remove the excess microbes coming from the process. T/F?

Back 28

True

Front 29

Water in sludge should be ______ when pumping?

Back 29

Minimized

Front 30

Sludge should be pumped often enough to prevent...

Back 30

Septic Sludge

Front 31

Sludge should be withdrawn ______....

Back 31

Slowly

Front 32

Coning occurs when an operator draws sludge.....

Back 32

Too Quickly

Front 33

What type of disk can be used to check water clarity?

Back 33

Sekke Disk

Front 34

Effluent from clarifier passes over what?

Back 34

Weir

Front 35

Clarifiers can be sized or rated by three methods:

Back 35

Detention Time (Hours)

Weir Overflow Rate (GPD/ft)

Surface Loading Rate (GPD/ft^2)

Front 36

Primary Clarifiers are not normally used with which Secondary Treatment methods?

Back 36

Package Plant

Oxidation Ditch

Oxidation Pond

Front 37

FOUR main parts of a Trickling Filter

Back 37

1. Under-Drain System

2. Retaining Wall

3. Media

4. Distribution System

Front 38

Trickling Filters depend on a straining action for the treatment: T/F

Back 38

False

Front 39

Examples of Trickling Filter media:

Back 39

Rock, plastic, red wood

Front 40

Trickling Filter media is a consistent size for good air flow through the media: T/F

Back 40

True

Front 41

What grows on Trickling Filter media?

Back 41

Zoogleal Film

Front 42

What process is a Trickling Filter?

Back 42

Aerobic

Front 43

How can you increase efficiency of a Trickling Filter plant?

Back 43

Add Recirculation

Front 44

Shock Loads are handled better by Activated Sludge or Trickling Filters?

Back 44

Trickinly Filters

Front 45

What causes Shock Loads?

Back 45

High Flow or High Organic Loads

Front 46

The Distributor Arm dispenses the water through?

Back 46

Orifices

Front 47

What powers the Distributor Arm?

Back 47

Jet action through orifices

Front 48

What is the purpose of a Turnbuckle?

Back 48

Level the Distribution Arm

Front 49

Name some problems with a Trickling Filter:

Back 49

Ponding

Odors

Filter Flies

Poor Effluent Quality

Freezing

Sloughing

Front 50

Trickling Filters should remove ___% of BOD.

Back 50

75%

Front 51

Trickling Filter effluent is slightly ____ and _____ than Activated Sludge.

Back 51

Turbid

Less quality

Front 52

In the Activated Sludge process the microbes grow _____ in the water column.

Back 52

Suspended

Front 53

Activated Sludge must have a DO above what?

Back 53

2-4 ppm

Front 54

What organisms are indicators of good, healthy sludge culture?

Back 54

Rotifers

Front 55

Mixed Liquor

Back 55

Contents of the aeration tank that contains: wastewater, activated sludge, and air.

Front 56

MLSS stands for

Back 56

Mixed Liquor Suspended Solids

Front 57

Typical MLSS range

Back 57

1000 to 2000 ppm

Front 58

Color of Activated Sludge should be medium to rich _____ ______.

Back 58

Dark Brown.

Front 59

Activated Sludge should remove what percentage of BOD?

Back 59

90-95%.

Front 60

What is the term for the amount of time sludge in the system before it is waste?

Back 60

Sludge Age.

Front 61

Typical Sludge Age for Activated Sludge

Back 61

3.5-7.0 Days

Front 62

F/M Ratio

Back 62

Food to Microorganism Ratio.

Front 63

The "Y-Wall" promotes...

Back 63

Good movement mixing in the aeration tank.

Front 64

Two basic types of sludge Digesters.

Back 64

1. Aerobic

2. Anaerobic

Front 65

Normal temperature of an unheated anaerobic digester?

Back 65

95*F (Near Body Temp)

Front 66

Anaerobic digesters produce what two gases?

Back 66

Methane and Carbon Dioxide.

Front 67

The two groups of bacteria which are necessary to digest sludge in an anaerobic system are:

Back 67

Acid Formers and Gas Formers

Front 68

Digester is called 'sour' when?

Back 68

It is acidic.

Front 69

Good sludge digestion reduces the volumes of solids by about ____%

Back 69

50%

Front 70

What is a well digested sludge called?

Back 70

Stabilized.

Front 71

Where can digested sludge be dried?

Back 71

Sand Bed.

Front 72

Type of digested sludge dewatering.

Back 72

Mechanical Dewatering.

Front 73

Ponds are usually less or more expensive to build and operate?

Back 73

Less.

Front 74

What two processes do ponds rely on for aeration?

Back 74

Algae and Wind.

Front 75

Typical pond pH permit limits

Back 75

6-9 pH.

Front 76

Where do you sample in a pond for performance?

Back 76

All FOUR corners.

Front 77

Types of Ponds and their depths.

Back 77

1. Aerobic 1-3ft

2. Anaerobic 10 or more ft

3. Facultative 3-5ft

Front 78

Slope of pond levee

Back 78

1:2

Front 79

Maintain how many foot/feet of water to keep emergent weeds from growing in pond?

Back 79

3ft.

Front 80

Blue green algae can be controlled with?

Back 80

Barley Hay

Front 81

Fences around ponds should have warning signs how often?

Back 81

Every 300ft.

Front 82

How can Dikes be damaged?

Back 82

Weeds, Burrowing animals, Tree Roots

Front 83

How do you prevent short-circuiting in ponds?

Back 83

Building them multi-celled.

Front 84

Nutrient for algae include:

Back 84

Nitrogen and Phosphorus

Front 85

If pond is oxygen deficient, what can be added as a short term solution.

Back 85

Sodium Nitrate.