Water Treatment Chapter 9: Taste And Odor Control

Front 1

What are the most common types of water quality complaints received by a water utility?

Back 1

Taste, odor, and color

Front 2

What types of materials in runoff waters can lead to oxygen depletion?

Back 2

1. Nitrogen and phosphorous containing compounds

2. Organic matter

Front 3

What 2 COMPOUNDS can produce earthy and musty odors in the water?

Back 3

Geosmin and MIB

Front 4

Aeration is best suited for treating what type of taste and odor problem?

Back 4

Odor problems caused by volatile compounds

Aeration is less successful in treating taste problems because these are more associated with less volatile compounds

Front 5

When ammonia is added to the treatment process, what common taste and odor compounds may be formed?

Back 5

Odoriferous Inorganic Chloramines

Front 6

What terms are used to describe the adsorptive capacities or ratings of activated carbons?

Back 6

-Phenol number

-iodine number

Front 7

How would you respond to a permanganate overdose?

Back 7

Treat with activated carbon or increase the pH so that the manganese precipitates faster

Front 8

When might the use of chlorine be the wrong treatment for a taste and odor problem?

Back 8

In waters containing phenols. It could result in the production of highly objectionable chloro-phenolic compounds

If the water contains organics it could lead to the formation of THMs

Front 9

Where are the most likely sources for the development of tastes and odors in a TREATMENT PLANT?

Back 9

Parts of the system that are used for untreated water. There is no chlorine residual in these parts, which allows organisms to thrive

Front 10

What common blue-green algae are associated with earthy/musty odors?

Back 10

1. Microcystis

2. Anabaena

3. Aphanizomenon

4. Oscillatoria

(ti-MAAO!!)

Front 11

Name two groups of BACTERIA that are known to produce taste and odor compounds in water

Back 11

-Sulfur reducing bacteria

-Actinomycetes

(get your act together sulfur reducing bact!)

Front 12

Which inorganic chloramine causes the most ODOR problems in treated water?

Back 12

Dichloramine

Front 13

Which types of algae are known to produce taste and odor compounds?

Back 13

Blue-green algae

Diatoms

Dinoflagellates

Yellow-green algae

(Blue yellow dinosaurs die atomic)

Front 14

What are the four GENERAL causes of taste and odor problems?

Back 14

Natural conditions

Environmental conditions

Human activities

Specific taste and odor compounds

Front 15

What is a slurry?

Back 15

A watery mixture or suspension of insoluble (not dissolved) matter

Front 16

What is the first warning that a water supplier has a cross connection problem?

Back 16

Complaints about a musty, septic, or other strange odor

Front 17

What information should be recorded on a water quality complaint form?

Back 17

1. Date and time of complaint

2. Location (Address)

3. A complete description of the problem

Front 18

How can PAC penetration through a filter be detected?

Back 18

By passing 1 Liter of filter effluent through a 0.45 um membrane filter. If the white membrane of the filter darkens, PAC is present.

Front 19

What adjustments could you make if PAC tends to cake on the surface of the filters?

Back 19

Adjust the sedimentation process to remove more PAC before it reaches the filters

Front 20

What is the most common ADSORPTIVE technique used specifically for taste and odor control?

Back 20

Powdered activated carbon (PAC)

Front 21

What is a distinct advantage of ozone over chlorine treatment for taste and odor?

Back 21

When using ozone, objectionable byproducts do not normally form

Front 22

What is key to successful taste and odor control?

Back 22

Prevent tastes and odors from ever developing

Front 23

What 2 forms of activated carbon are used in water treatment?

Back 23

1. Powdered activated carbon (PAC)

2. Granular activated carbon (GAC)

Front 24

What causes the diurnal dissolved oxygen cycle?

Back 24

Algae that produce oxygen during the day (photosynthesis) create supersaturated conditions (increases pH). During the night, algae remove dissolved oxygen from the water (respiration), producing carbon dioxide (decreases pH) and lowers dissolved oxygen levels, which leads to anaerobic conditions

Front 25

Where is PAC usually applied in the treatment process?

Back 25

The flash mixer

(Pack it in the flash mixer)

Front 26

Why must chlorine dioxide be generated on site?

Back 26

It is unstable and cannot be stored

Front 27

What types of odors can often be decreased by chlorination?

Back 27

Fishy, grassy, or flowery odors

Front 28

How does the use of chlorine influence tastes and odors when water contains algae?

Back 28

The reaction of chlorine on algal cells results in the release of objectionable materials into the water

Front 29

How can tastes and odors caused by algae be removed most economically in a water treatment plant?

Back 29

By improving coagulation and sedimentation. This procedure will lengthen filter runs

Front 30

List the two BROAD categories of taste and odor treatment methods

Back 30

Removal

Destruction

Front 31

How do the chemicals used in a water treatment plant interfere with a search for the source of taste and odors?

Back 31

Chemicals such as chlorine and activated carbon tend to mask any changes in taste and odor

Front 32

What are the two GENERAL ways in which microbial populations can contribute to unpleasant taste and odors?

Back 32

-The production of metabolic byproducts (****)

-The release of cellular materials (death)

Front 33

List the major causes of tastes and odors in a water system

Back 33

1. Algal blooms in source waters

2. Disinfectants used

3. The distribution system

(ADD)

Front 34

What are the six specific taste and odor COMPOUNDS?

Back 34

Geosmin

MIB

Chlorine

Chloramines

Aldehydes

Phenols and Chlorophenols

Front 35

What is responsible for the depletion of oxygen in water?

Back 35

Microorganisms (or corrosion)

Front 36

What is degasification?

Back 36

Removal of odor-producing substances that are volatile

Front 37

What is the most common method used for taste and odor control?

Back 37

Chemical oxidation, because of the widespread use of chlorine

Front 38

What is potassium permanganate?

Back 38

A strong chemical oxidizer that can be used to destroy many organic compounds

Often used for COLOR control

Delivered by dry feeder

Don't store near activated carbon, they are both flammable

Front 39

If a consumer finds pink tap water, what might be the problem?

Back 39

Potassium permanganate overdose. Treat with PAC or increase the pH which will cause the potassium permanganate to precipitate faster

Front 40

What is Ozone?

Back 40

An unstable form of oxygen that is an extremely powerful oxidant

-stronger oxidant than chlorine

-generated on site

-Does not create objectionable byproducts when treating for tastes and odors

-does not effectively inactivate some viruses, spores, and cysts

Front 41

What is chlorine dioxide?

Back 41

A strong oxidant created by combining sodium chlorite and chlorine

-it is unstable and must be generated on site

-does not create THMs

-does not react with the reducing agent ammonia

-very effective at higher pH (8-10)

Front 42

What is the most common technique used for taste and odor control in treatment plants?

Back 42

Powdered activated carbon (PAC)

-Applied at any point prior to filtration

-chlorine will react with carbon and neutralize the effects of both

-Applied at the plant Flash mixer

Front 43

What are the three methods that are used for taste and odor control?

Back 43

1. OXIDATION: chlorine, potassium permanganate, ozone, chlorine dioxide

2. AERATION: Used to treat odor problems caused by volatile compounds

3: ADSORPTION: PAC and GAC

Front 44

What is used to oxidize iron, manganese, and sulfide compounds?

Back 44

Potassium Permanganate, but chlorine dioxide is more commonly used to treat Iron and manganese