Water Flashcards
(150 cards)
1
Q
The biological activity of an aquatic ecosystem depends on the activity of what?
A
Primary producers
2
Q
What are 4 examples of primary producers?
A
oxygenic photoautotrophs, phytoplankton. Algae, Cyanobacteria
3
Q
What is one function of cyanobacteria?
A
fix nitrogen
4
Q
What organisms serve as a food source for chemoheterotrophs?
A
bacteria, protozoa, fish, other aquatic organisms.
5
Q
zoo =
phtyo =
A
- animal
- plant
6
Q
What factors are the activity and net number of phytoplankton dependent on?
A
Temperature, light received, limiting nutrient availability
7
Q
What limiting nutrients are phytoplankton sensitive to?
A
Nitrogen, Phosphorus
8
Q
What is the photic zone?
A
The depth (m) that light will penetrate to in clear water
9
Q
How deep will light penetrate in clear water?
A
300 m
10
Q
How are microorganisms able to harvest the little amount of light that reaches them?
A
Via accessory pigments
11
Q
Halotolerant organisms can reach salt levels up to what %?
A
3%
12
Q
__% of the ocean is deeper than ___ m.
A
75%, 1000 m.
13
Q
What is the deepest depth of the ocean? What is the pressure here?
A
11 km below the surface. 1100 atmospheres (~1 atm/ 10 m)
14
Q
At what depth does the temperature of the ocean stay constant? What is the constant temp?
A
Below 100 m, 2-3 Celcius
15
Q
Synonym for open ocean
A
Pelagic zone
16
Q
What is very low in the Pelagic Zone? Why?
A
Primary productivity. Lack of inorganic nutrients (nitrogen, phosphorus, iron) that are required by phytoplankton.
17
Q
The open ocean is __________.
A
Oligotrophic
18
Q
Oligotrophic
A
relatively low in plant nutrients and containing abundant oxygen in the deeper parts
19
Q
What is the temperature like in the open ocean compared to shore?
A
Cooler and more constant
20
Q
How are nutrients brought up to the surface in some regions of the open ocean?
A
wind and ocean currents cause an upwelling of water from the ocean floor –> promotes productivity
21
Q
What does the majority of primary productivity come from in the open ocean?
A
prochlorophytes
22
Q
What are prochlorophytes?
A
Tiny phototrophs phylogenically related to cyanobacteria: Prochlorococcus
23
Q
Two common adaptations observed in pelagic microorganisms?
A
- Size reduction (high surface/volume ratio)
- High affinity transport systems
24
Q
3 characteristics of Trichodesmium
A
- Filamentous cyanobacteria
- Contains phycobilins
- Nitrogen fixation
25
What are the two primary producers of coastal waters?
- Algae
| - Cyanobacteria
26
Why is productivity usually higher in coastal waters?
Influx of nutrients from rivers and polluted water sources
27
What is an example of a source of influx of nutrients in coastal waters? What nutrients does this provide?
Agricultural runoff. Nitrogen, Phosphorus
28
What is a eutrophic body of water?
Has high biological activity due to excessive nutrients (phosphorus + nitrogen). Becomes dominated by aquatic plants or algae.
29
What might happen at coastal waters (eutrophic body of water)?
Red tides
30
What are 3 characteristics of red tides? Which nutrient is limiting?
Algal bloom, dinoflagellates, neurotoxins. Nitrogen
31
What does a higher level of primary productivity support in coastal waters?
High zooplankton and aquatic animal concentration.
32
What happens between 300 m - 1000 m in the deep sea? What is the tempurature? What type of extremophiles live here?
Chemoheterotrophs degrade organic matter that falls from the photic zones. 2-3 C, psychrophiles.
33
What are 3 characteristics of the deep sea below 1000 m?
1. Organic carbon is scarce
2. Oligotrophic
3. No light
34
What type of microorganisms live in the deep sea?
Psychrophilic, barophilic/barotolerant
35
Hydrothermal vents are a source of what?
Heat and nutrients
36
Are hydrothermal vents electron acceptors or electron donors?
Both
37
What type of creature live at hydrothermal vents?
Tube worms
38
Tube worms have a symbiotic relationship with what?
Sulfur oxidizing chemoautotrophs
39
What is the function of Tube Worms?
Trap and transport nutrients to the bacterial symbionts
40
Are freshwater environments open or closed systems?
Closed
41
In freshwater environments, the microbial population depends on what 2 factors? Limited by what 2 factors?
- Nutrients and light.
| - Nitrogen and Phosphorus.
42
Lake vs River mixing/aeration.
Lake - poor
| River - good
43
What nutrients are limiting in oligotrophic lakes?
N and P
44
The growth of what type of microorganisms is limited by nutrient supply in oligotrophic lakes?
Aerobic chemoheterotrophs
45
Oligotrophic lakes have a high concentration of what? Why?
Oxygen. The rate at which oxygen dissolves into the water from the air and plants is faster than the consumption rate by fish. "Oxygen saturated"
46
What gets degraded completely in oligotrophic lakes?
Organic matter
47
What does an oligotrophic lake look like?
Clear!!! (Deep light penetration)
48
Eutrophic lake
1. Primary production?
2. [Organic Matter]?
3. Chemoheterotroph growth?
4. Dissolved oxygen?
5. [Oxygen]?
6. Light penetration?
7. Creation of what type of zones?
1. High (algal bloom)
2. High availability
3. Rapid
4. Rapid depletion
5. Low
6. Poor
7. Anaerobic
49
Eutrophic lake health risks?
Pathogens, bloom of cyanobacteria/algae (secreted toxins)
50
Bottom sediments support the growth of what type microorganisms in Eutrophic lakes? How?
Denitrifies, methanogens, sulfate reducers (H2S). Anaerobic and contain organic matter (dead primary producers)
51
Photosynthesis in eutrophic lakes
Anaerobic photosynthesis - H2S = electron donor and produces sulfate (used by sulfate reducers)
52
Why do eutrophic lakes smell bad?
B/c of excessive H2S/organic acid production from fermentation
53
Why might fish/aerobic organisms die in eutrophic lakes?
Lack of O2/presence of H2S
54
Why do anaerobic zones form in lakes in temperate (our) climates?
Due to summer stratification (thermal stratification = temperature edges)
55
What is the epilimnion layer in lakes in temperate climates?
Less dense aerobic layer that forms at the surface of the water as the air temperature increases
56
What is the hypolimnion layer in lakes in temperate climates?
The colder bottom layer. More dense, anaerobic
57
What zone separates the epilimnion layer from the hypolimnion layer in lakes?
Thermocline
58
What is the thermocline zone in lakes?
Zone of rapid temperature change
59
When does mixing of all three layers take place? Purpose?
Spring and fall. Brings nutrients back up the water column
60
What does good mixing/aeration ensure in rivers?
That organic matter is degraded effectively.
- No fermentation
- No H2S production
61
What can excess organic matter lead to in rivers?
Anaerobiosis
62
Major source of pollution in freshwater?
Sewage
63
What is sewage rich in? What might it contain?
Organic matter. Pathogens
64
What is BOD (Biochemical Oxygen Demand)?
A measure of the extent of pollution by organic matter.
65
What tends to happen to polluted water?
Becomes anaerobic --> fermentation, sulfate reduction, nitrate reduction
66
What is a biofilm?
Microbial cells embedded inside an extracellular matrix
67
Are biofilms normally produced by one or many populations of species?
many populations
68
What is the extracellular matrix of biofilms made up of?
Proteins, polysaccharides, DNA
69
What are planktonic cells?
Free-living cells
70
Cells inside biofilms are more resistant than planktonic cells to what?
stress
71
What 3 places can biofilms be found?
Water systems (natural and man made), on wet surfaces, growing on medical devices
72
Where do most water-born pathogens grow?
Intestinal tract of animals
73
How is the transmission of water born pathogens mediated?
Fecal contamination of water supplies
74
What are two sources of water-born pathogen infection?
1. Portable water (drinking and food preparation)
| 2. Recreational water (swimming)
75
Salmonella Typhi (water-born bacterial pathogen/virus)
Typhoid fever in humans, systemic infection, healthy carriers
76
Vibrio Cholerae (water-born bacterial pathogen/virus)
Cholera, severe diarrhea (enterotoxin)
77
Shigella spp. (water-born bacterial pathogen/virus)
Shigellosis; bacterial dysentery (bloody diarrhea, inflammation of the intestinal mucosa)
78
Campylobacter spp. (water-born bacterial pathogen/virus)
Gastroenteritis, most common cause of gastroenteritis in Canada
79
Enterovirus (water-born bacterial pathogen/virus)
Poliovirus, norovirus, rotavirus (children)
80
Hepatitis A Virus
(water-born bacterial pathogen/virus)
81
What are the 3 water-born pathogenic protozoa?
Enramoeba histolytica, Giardia lamblia, cryptosporidium parvum
82
What does Entameoba histolytico cause?
Amoebic dysentery. A single-celled animal that catches food and moves about by extending fingerlike projections of protoplasm, causes infection of the intestines resulting in severe diarrhea with the presence of blood and mucus in the feces.
83
What are two nicknames for Giardia lamblia?
Backpacker's disease - Beaver feaver
84
What does Giardia lamblia cause? Often associated with what? What animals are frequent carriers?
Chronic diarrhea. Associated with drinking water in wilderness areas. Beavers and muskrats.
85
What are side effects of cryptosporidium parvum?
Chronic and acute diarrhea
86
How is cryptosporidium parvum treated?
No reliable treatment
87
Cryptosporidium parvum is present in what % of sewage samples? River waters? Drinking waters?
90%. 75%. 28%.
88
Cryptosporidium parvum is a major problem for what individuals? Self limiting in what individuals?
Immunocompromised individuals. Healthy people.
89
What do both G. lamblia and C. parvum form?
Cysts that are resistant to disinfectants (chlorine).
90
Which bacterium is not effectively removed by the filtration process in water plants? Why?
C. parvum. Too small
91
What are most water born pathogens associated with?
Fecal material
92
How do you test for pathogens in water?
Test the water for organisms that are present in large # in feces --> indicator of fecal pollution.
93
What two pathogens act as indicators of fecal pollution in water quality control?
Coliforms, fecal coliforms
94
Coliforms
1. Respiration?
2. Gram?
3. Spore formation?
4. Shape?
5. Lactose fermentation?
1. facultative aerobic
2. Gram negative
3. non spore-forming
4. rod-shaped
5. Can ferment lactose with gas formation within 48 hours at 35C.
95
What are fecal coliforms?
Coliforms derived from the intestines of warm-blooded animals
96
At what extreme temperature can fecal coliforms grow at?
44.5C. Thermotolerant!
97
What is an example of a fecal coliform?
E. Coli
98
What does the presence of fecal coliforms indicate?
Fecal contamination and that the water is unsafe for human consumption.
99
Is fecal coliforms are not found in water, is the water safe?
No, there may be cysts in the water
100
What does Most Probable Number (MPN) test for?
Coliforms
101
In an MPN test, what are the samples added to? How do you know if the test is positive?
Lactose broth. Positive is gas production is detected.
102
What does membrane filtration test for?
Coliforms and fecal coliforms.
103
What volume of water must be tested for membrane filtration?
100 mL (large volume)
104
Why is membrane filtration a better method than MPN?
Faster and easier
105
What are the 4 aims of water treatments?
- Remove pathogens
- Improve clarity of water
- Remove compounds that give bad smell or taste
- Soften the water
106
What are the 4 steps in water treatment?
1. Sedimentation
2. Flocculation treatment
3. Filtration
4. Disinfection
107
What happens in Sedimentation? What does this allow?
Water is left to stand in a reservoir (sedimentation basin). This allows large particles (sands) to settle.
108
What is another term for floculation treatment?
Chemical coagulation
109
What happens during the Floculation Treatment step?
1. A floculating chemical (coagulant) is added.
2. Water is transferred to a flocculation basin and allowed to settle for 6h.
3. As the flocs (flaky precipitates) form, they trap fine particles (clay, bacteria, viruses, protists, organic chemicals)
110
What % of bacteria, color and particles have been removed by the end of the flocculation treatment?
80%
111
What is the water filtered through during the filtration step? Why?
Sand. To remove remaining particles/bacteria/any remaining G. lamblia cysts.
112
What % of bacteria have been removed by the end of the Filtration stage?
98-99.5%
113
What regularly occurs in the filter to prevent clogging?
Backflushing
114
What are the two main methods of disinfection?
Chlorination, Ozone.
115
What is the purpose of using chlorine to disinfect water?
Chlorine is very reactive in water --> it forms strong oxidizing agents
116
What two things does the chlorine do in the water?
Kills remaining microorganisms, neutralizes most of the chemicals that give water a bad smell/taste.
117
What is residual chlorine? Is this good or bad?
The amount of chlorine that remains in the water that left the treatment plant. Good: desired/required to protect the distribution system.
118
is Ozone of Chlorination more effective? Why?
Ozone. Kills G. lamblia and C. parvum cysts.
119
What is a downfall of Ozone treatment?
Very short half-life
120
What is the requirement for water treatment quality control in montreal?
< 10 coliforms/100ml
| < 1 fecal coliform/100ml
121
What is a synonym for wastewater?
Sweage
122
What is the aim of wastewater (sewage) treatment?
- Reduce BOD (remove/destroy organic matter)
| - Destroy pathogens
123
What happens during primary treatment of wastewater?
40-70% of the suspended solids settle to the bottom of sedimentation tanks.
124
What is added to the sedimentation tanks in wastewater primary treatment? What does it produce?
Flocculation chemical which produces primary sludge.
125
What does BOD stand for?
Biochemical oxygen demand (BOD)
126
Primary treatment reduces the BOD of wastewater to what %? the bacteria by what %?
25-40%
| 25-75%
127
What are the two paths that wastewaters can go after primary treatment?
1. Discharged to waterways
| 2. Go through secondary treatment
128
What is the purpose of secondary treatment?
use microorganisms to reduce the BOD and [bacterial] further.
129
What are the 2 types of secondary treatments?
Liquid, sludge
130
What are the two types of liquid secondary treatments for sewage water?
1. Trickling filter
| 2. Activated sludge
131
What is water sprayed over in a trickling filter?
A bed of rock or plastic honeycomb
132
What do the microorganisms form on the bed of rock or plastic honeycomb in a trickling filter? What does this do?
Biofilms which coat the surface and oxidize the organic matter present in the sewage
133
What is the BOD reduced by after water has gone through a trickling filter? bacteria by?
- 80-95%
| - 90-95%
134
What happens during the activated sludge process of the secondary treatment (liquid)? What does this cause?
Air is blown through the liquid from primary treatment. This causes slime-forming bacteria to grow and clump together to form flocs (activated sludge). Then the liquid passes to a settling tank.
135
What do these flocs do?
They oxidize the organic matter
136
What happens at the settling tank during the activated sludge process?
The sludge is removed for disposal or secondary treatment.
137
At the end of the Activated sludge process of wastewater, what is the BOD and bacteria reduced by?
85-95%
| 90-98%
138
What do primary and secondary sludge contain?
Cellulose and other organic compounds
139
What are primary and secondary sludge subject to?
Microbial digestion under anaerobic conditions
140
What can the CH4 produced during the secondary treatment of sludge be used for?
To power the treatment plant
141
What is the biochemical oxygen demand (BOD) reduced by after the secondary sludge treatment?
90%
142
What happens to the material that remains after the secondary sludge treatment?
Incinerated or burried
143
What is the purpose of the tertiary liquid treatment?
Further reduce the BOD, bacteria and [N & P]
144
Tertiary liquid treatment may involve any/a combination of which 4 processes?
- Biological treatment (ponds:algae)
- Flocculation
- Filtration
- Chlorination or ozonation
145
What is the final drinking water product called?
The final liquid effluent. Fecal coliforms and coliforms are below limits.
146
What is required in the maintenance of a septic tank? Why?
periodic emptying due to the settling of the material and minimal sludge digestion
147
After treatment by a septic tank, the BOD of effluent is reduced by what %?
60%
148
Where does the final liquid effluent flow to once it leaves the septic tank?
Flows to a leaching field (tile field)
149
The final liquid effluent that leaves a spetic tank contains how many coliforms/mL?
10,000 coliforms/mL
150
What is the role of soil & organisms (at the leaching field) to the effluent that leaves the septic tank? Care has to be taken to prevent contamination of what?
Soil: Filter
Organisms: Decompose O.M.
Groundwater and nearby waterways
