Microbes and Water Part 1

Question 1

What is water pollution?

Answer 1

Biological changes harmful to water quality

Question 2

What is water potability?

Answer 2

Tells you whether or not the water is safe to drink

Question 3

What can you expect to find in unpolluted water?

Answer 3

Low organic nutrients therefore low numbers of microbes

Question 4

How can water be polluted?

Answer 4

• Sewage
• Agricultural runoff (phosphates)
• Industrial runoff (actual chemicals)

Question 5

What can you expect to see in polluted water?

Answer 5

High in organic matter and coliform and noncoliform bacteria

Question 6

What are accumulated phosphates?

Answer 6

They are from agricultural or industrial runoff and cause algal blooms

Question 7

What do algal blooms do?

Answer 7

Supply nutrients to other microbes which use of the oxygen in the water
-aquatic and plant life die and accumulate on the bottom where anaerobic bacteria decompose the material further using the available oxygen

Question 8

What are the 3 types of water pollution?

Answer 8

Physical: sand, soil, cyanobacterias blooms
Chemical: inorganic, organic waste
Biological: Microorganisms from anthropogenic sources

Question 9

What is the BOD?

Answer 9

Biological Oxygen Demand of water is the amount of water microbes need to decompose organic matter
-used to describe the pollution status of waters

Question 10

What happens when a nutrient enters a water body as a pollutant?

Answer 10

It provides nutrition to microbes and in using that nutrient they will use oxygen

Question 11

What happens when a body of water has a high BOD?

Answer 11

It is able to support rapid microbial growth and can lose oxygen quickly. possible causing a fish kill

Question 12

What is the definition of eutrophic?

Answer 12

Waters that are overloaded with nutrients

-can cause water discolouriton

Question 13

What types of diseases can be transmitted by water?

Answer 13

• Typhoid fever
• Cholera
• Shigllosis
• Legionnaires disease

Question 14

What is Erysipeloid?

Answer 14

infection caused by the Marine pathogen Erysipelothrix rhusiopathiiae

Question 15

What does mycobacterium marinum cause?

Answer 15

Lesion (granuloma) at the site of a wound called Fish Handlers Disease

Question 16

What can Vibrio vulnificus cause?

Answer 16

Intestinal illness if raw oysters are consumed

Wound infections involving gangrene and necrotizing fasciitis

Question 17

What viruses can water transmit?

Answer 17

Hep A
Rotavirus
Gastroenteritis
Polio

Question 18

What eukaryotic organisms can water transmit?

Answer 18

Entamoeba histolytica
Giardia lamblia
Crytosporidium

Question 19

What aree dinoflagellates able to transmit through water?

Answer 19

A toxin which causes ciguatera poisoning in humans

Question 20

What is used to assess water pollution?

Answer 20

Fecal coliforms

Question 21

What is a fecal coliform?

Answer 21

rod shaped gram - bacteria normally resident in our large intestines or the intestines of animals such as farm cattle pigs etc.

Question 22

What is the usual organism that indicates water pollution?

Answer 22

E coli, usually indicated fecal contamination of municipal drinking water supplies

Question 23

Where do coliforms not grow?

Answer 23

Streams
Lakes
Spill sites

Question 24

What is another example of a bacteria that is also in the coliform group?

Answer 24

Klebsiella

Question 25

Do all coliforms cause disease?

Answer 25

Many coliforms are NOT disease causing and are a normal component of our gut flora, and are commonly found in soils as well

Question 26

What is a Total Plate Count?

Answer 26

Microbiological tests performed to identify which bacteria is present and how many are there per mL

Question 27

What is a membrane filter?

Answer 27

used to pass large volumes of water through to retain bacteria from the water sample.
-Filter is then placed on a pad of nutrient medium so that colonies grow and can be counted

Question 28

What are colour indicator tests used for?

Answer 28

Special nutrient broth solutions are inoculated with samples and specific colour reactions which indicate the presence of coliforms
-Can usually tell the kind of bacteria that is present

Question 29

What are municipal water supplies treated with?

Answer 29

Flocculating agents

-Alum

Question 30

What is the purpose of alum?

Answer 30

Binds with suspended matter and forms flocs that sink and can then be removed and then the water is filtered through sand beds

Question 31

What is the 3 steps for water purification?

Answer 31

Sedimentation: Removes large objects and particles through flocculation

Filtration: removes microorganisms by passing water through a layer of sand, gravel and microbe biofilm

Chlorination: involves adding chlorine gas to kill remaining organisms

Question 32

What is chlorine used in water purification?

Answer 32

To kill microbes.

Question 33

In what form is chlorine injected into the water?

Answer 33

In gas form

Question 34

Why do we have to monitor the chlorine process carefully?

Answer 34

Chlorine will bind with organic matter in the input water
-enough has to be added to bing all organic matter and still have enough free chlorine leftover to kill bacteria (but only just enough)

Question 35

How is the chlorine dosed?

Answer 35

Needs to be enough to kill microbes both in the treatment plant and in the piping used to distribute the water to the end user

Question 36

What should happen to the Chlorine when it gets to the end user?

Answer 36

There should be virtually no free chlorine present