AQUATIC CHEM QUIZ 3 Flashcards

1
Q

What key processes do micro organisms carry out in water chemistry?

A

Photosynthesis and respiration

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2
Q

What are organic hazardous substances carried through water as?

A

As emulsions of very small particles suspended in water

Some hazardous materials are deposited in sediments

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3
Q

Autotrophic

A

Use solar/chemical energy to fix elements from simple non-living inorganic material—>complex life molecules that compose living organisms

PRODUCERS

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4
Q

Heterotrophic

A

Use organic substances produced by autotrophs as energy sources & as a raw material for the synthesis of their own biomass

Cannot produce its own food

DECOMPOSERS(bacteria, fungi)

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5
Q

The roles of micro organisms in water

A
  1. Oxygen production
  2. breakdown of biomass
  3. Catalysts of aquatic chemical reactions
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6
Q

Examples of microorganisms in water

A
  1. Algae
  2. fungi
  3. bacteria
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7
Q

Aerobic

A

Require molecular oxygen as an electron receptor

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8
Q

Facultative bacteria 

A

Uses free oxygen and other substances as electron receptors

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9
Q

Ways other than photosynthesis and respiration that microbes are involved in the C cycle

A
  1. Degradation of biomass
  2. Methane production
  3. Degradation of hydrocarbons
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10
Q

What is Nitrogen fixation

A

Any natural/ industrial process that causes free nitrogen

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11
Q

What is nitrification?

A

Reduced nitrogen compounds are oxidised to nitrite & nitrate

The conversion of N(-III) to N(V)

2O2 + NH4+ —> NO3- + 2H+ + H2O

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12
Q

What is Nitrate reduction?

A

Nitrate used as an electron acceptor in anaerobic conditions

2NO3- + {CH2O} —> 2NO2- + H2O + CO2

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13
Q

What is Denitrification?

A

A process I converts nitrate to nitrogen gas

End product- N2

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14
Q

What are the four trophic classifications of lakes?

A
  1. Oligotrophic - little to no aquatic vegetation
  2. Mesotrophic- intermediate productivity
  3. Eutrophic- large quantities of organisms (algal blooms)
  4. Hypereutrophic- excessive algal growth

OMEH

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15
Q

Liebig’s Law of the Minimum states: 

A

If one of the essential plant nutrient is deficient, plant growth will be poor even when all other essential nutrients are present
or
The yield of a given species should be limited by the nutrient that was present in the least quantity in the environment relative to its demand for growth

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16
Q

What are the Key variables for eutrophication?

A

Sunlight
Nitrogen
Phosphorus

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17
Q

TN stands for

TP stands for

A

Total nitrogen

Total phosphorus

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18
Q

Chl a stands for

SD stands for

A

Chlorophyll a

Secchi disk transparency

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19
Q

Factors that can influence eutrophication

A

Dissolved oxygen
Light
Macronutrients (Ca, Mg, K)
Salinity

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20
Q

What is eutrophication?

A

An enrichment of water by nutrients that cause structural changes to the ecosystem

E.g excessive growth of algae
Depletion of fish species
Deterioration of water quality

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21
Q

What does OECD stand for?

A

Organisation for economic cooperation and development

22
Q

Affects cultural eutrophication is having on water bodies

A

Cultural eutrophication is caused by humans speeding up the process of natural eutrophication

Causing an abundance of particular substances, e.g. phytoplankton, bacteria, fungi & debris which determines the turbidity of water.

Low biodiversity
Depletion of fish
Low BOD levels

23
Q

Signs of excessive eutrophication

A

Bad odour
Bad taste
Depletion of fish
Potentially toxic algae 

24
Q

Cause of an excessive amount of nutrients

A

1.Fertilisers and agricultural run-off
2.Discharge of WASTE WATER

25
Q

Nuisance Harmful Alage or Harmful Algal Blooms (HABS)

A

No toxins but high biomass

26
Q

Toxic Harmful Alage or Harmful Algal Blooms (HABS)

A

Those that produced toxins or metabolites harmful to humans/ animals

27
Q

What is a pesticide?

A

A substance for preventing or destroying pests

28
Q

What techniques/steps are used in water treatment?

A
  1. Pre-treatment
  2. Mixing and coagulation
  3. Settlement
  4. Filtration
  5. Disinfection
29
Q

Where is raw freshwater abstracted from?

A

Rivers, lakes and underground sources to be treated for human consumption

30
Q

What are the objectives of water treatment?

A

safe for human consumption aesthetically appealing

reasonable cost

31
Q

Public water supplies normally service the requirements of where

A

Domestic households
Industry
Commercial

32
Q

What are the two sets of standards for water quality

A
  1. Quality of raw water

2. Quality of treated water

33
Q

What are the four classes of water treatment?

A

Class A- no treatment
Class B- used for public supplies, disinfected
Class C- standard treatment, from lowland areas & reservoirs
Class D- when industries require high quality/ source is down stream of urban develpments

34
Q

What processes occur in pre-treatment of water?

A
Screening
Raw water storage 
Aeration
Preliminary settling
Prechlorination

SRAPP

35
Q

Purpose of screening and water treatment

A

To remove large floating debris and suspended solids (leaves, twigs, plastics) 

36
Q

What three types of screens are used for screening

A

Bar screens
Band and drum screens
Micro strainers

37
Q

What is raw water storage?

A

Practical temporary storage
Water usually needs to be stored before treatment
Usually stored in reservoirs

38
Q

Benefits of raw water storage

A
  1. Natural settlement occurs
  2. Reduction in number of pathogenic bacteria
  3. Water quality improves with storage especially relating to suspended solids
39
Q

Benefits of aeration 

A
  1. Improves raw water quality
  2. Supplies oxygen
  3. Liberates unwanted gases e.g. CO2
  4. Cheap process
40
Q

What is Chlorination 

A

And essential method of disinfection

LAST STAGE of treatment

41
Q

What is prechlorination

A

Injecting chlorine into raw water straight after abstraction from river

Used on water with HIGH BACTERIAL COUNT

42
Q

Why is chlorination still necessary after prechlorination?

A

Organic matter reacts with chlorine at this stage reducing its effectiveness as a disinfectant

43
Q

Negatives of prechloriantion?

A

High amount of chlorine needed, moreso than later stage chlorination

44
Q

Example of a coagulant

A

Ferric chloride

45
Q

Purpose of filtration

A

To remove fine non-settleable particles from water

46
Q

Name three types of filtration

A
  1. Slow sound filtration
  2. Rapid sand filtration
  3. Activated carbon
47
Q

Deficiency affiliation depends on

A
  1. The size and shape of the media

2. Rate flow of water through the filter

48
Q

Limitations of Chlorination 

A

Chlorination byproducts- potential long term effects
taste and odour issues can affect quality 
Lower effectiveness in TURBID WATERS

49
Q

Example of chlorination by product

A

Trihalomethanes

50
Q

What type of water is prechlorination generally used on?

A

Water with high bacterial count