environment Flashcards

1
Q

what is residence time

A

the average time a substance or mass spends in a specific place or medium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how do you calculate residence time

A

= amount of substance in the reservoir / rate inflow or outflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

does acid rain have short or long residence time

A

short, fairly local phenomenon,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does acid rain cause soils to emit

A

Al3+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is smog

A

combination of smoke and fog in the atmosphere made up of nitrogen, sulphur oxide, ozone …

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

examples of primary pollutants

A

volatile hydrocarbons
nitrogen oxides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

examples of secondary pollutants

A

ketones
aldehydes
ozone (O3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is temperature inversion

A

cooler air skips underneath warmer air so the layer of war air is trapped inbetween 2 layers of cool air.

this causes any pollutants released in that layer of cooler air stay close to the earths surface. which allows the primary pollutants to react and produce secondary pollutants and smog

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the normal condition in the Throposohere

A

temperature decreases as you go up. the warm and less dense air rises and takes pollutants with it.

the warmer air is then replaced with cool air which is again warmed up continuing the process.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the effects of PANs which can be found in smog

A

cause eye irritation and respiratory problems.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are 4 air pollution concerns

A

ozone hole
global warming
acid rain
smog

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

name 4 fossil fuels we need to clean up

A

SOx
coal
NOx
soot (e.g. for diesil engines)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is used to remove SO2 from the emissions of power plants

A

flue gas desulphurisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how does the flue gas desulphurisation work

A

reacts flue gas with limestone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how can NOx emissions be reduced considerably

A

2 stage combustion technology

1st stage - high temperature and low O2. (not enough O2 to react with N2)

2nd stage - Excess O2, but low temp so that N2 cannot react to give NOx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how do power station remove NOx

A

they use ammonia

4NH3 + 4NO + O2 -> 4N2 + 6H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

name 4 chemicals which impact to road pollution

A

NOx
particulate matter
CO
unburnt hydrocarbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is a three way catalyst

A

devise which reduces emissions from gasoline fuelled vehicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are the 3 tasks of a 3 way catalytic converter

A
  1. reduction of nitrogen oxides
  2. oxidation of CO -> CO2
  3. oxidation of unburnt hydrocarbons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what helps reduce harmful emissions from diesil engines

A

adblue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the definition of a critical element

A

elements crucial for technology development and the production of advanced energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are 4 examples of critical elements

A

helium
lithium
phosphorus
zinc
platinum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

where is shale oil extracted from

A

oil shale rock fragments underground

24
Q

what is the process of fracking - used to extract shale oil (4 steps)

A
  1. holes are drilled into the shale rock
  2. fracking fluids are then pumped in
  3. high pressure cracks the rock allowing the oil to flow into collection wells
  4. oil and gas is collected and shipped away for use
25
Q

what was the refined products of shale oil

A
  1. Lamp oil
  2. gas/fuel oil
  3. lubricating oil
26
Q

what are 2 by products of shale oil

A

sulphur and ammonia

27
Q

what are 3 environmental problems from modern shale oil

A
  1. the bings - artificial hills made from the remnants of shale oil
  2. fires in storage tanks and transport
  3. uses lots of water
  4. high emissions
28
Q

what are 3 environmental impacts from shale oil production

A
  1. uses lots of water
  2. leaking of fracking fluids into water causing contamination
  3. earthquakes near fracking sites
29
Q

what is fugitive methane

A

methane which escapes during fracking and transport of natural gases.

30
Q

what does PM stand for

A

particulate matter

31
Q

what is considered a thick layer of PM

A

2.5

32
Q

what is the pH of acid rain

A

< 5

33
Q

what are the 2 main chemical which cause acid rain

A

nitric and sulphuric acid from NOx and SOx emissions

34
Q

what is the difference In aluminium recycling to glass recycling

A

glass in more energy intensive.
however adding waste glass to silica makes it easier to melt, so partial glass recycling is beneficial but not as much as Al recycling

35
Q

what is the Gaia hypothesis

A

Organisms interact with their inorganic surroundings on earth to form a self regulating, complex system that contributes to maintaining the conditions for life on the planet.

36
Q

what are the 5 environmental cycles

A
  • Atmosphere - the layer of gases which surround the earth
    • Geosphere - the solid part of the earth
    • Hydrosphere - the sum of all water on Earth
    • Lithosphere - the rocky outer part of the earth
    • Biosphere - where life exists close to earth surface
37
Q

what are the 2 keys points to remember for residence time

A
  • Should use same mass units for reservoir amount and flux
    • Find a level/volume when the outflow from the leaks is equal to the inflow
38
Q

what is a reservoir

A

body of matter which has a relatively uniformly distributed physical, chemical or biological properties e.g. ocean, atmosphere, biosphere

39
Q

Flux

A

amount of material entering or leaving per unit time e.g. rain into ocean

40
Q

source

A

flux of material going into a reservoir plus rate of creation within the reservoir e.g. creation of ozone in ozone layer.

41
Q

sink

A

flux of material leaving reservoir plus rate of destruction within reservoir

42
Q

steady-state

A

when sources and sinks are in balance and do not change with time so that the concentration M does not change with time.

43
Q

what are the approaches to pollution control (there are 6)

A
  1. Dilution (not for persistent chemicals).
    1. End-of-pipe (collecting waste)
    2. Green chemistry
    3. Change consumer habits
    4. Cradle-to-grave analysis
    5. Driven by legislation and public opinion.
44
Q

what does the ozone layer do?

A

protects life on Earth from UV and solar radiation and plays an important role on the radiation budget of the atmosphere. The evolution of the ozone layer is coupled with climate change

45
Q

what is the chapman cycle

A

oxygen interacting with UV
- constantly being created and destroyed

46
Q

what molecules have an ozone destroying cycle

A

CFCs

  • chlorofluorocarbons
47
Q

what is the process of CFC breaking the ozone layer

A

chlorine initiates the breakdown of ozone and combines with a freed oxygen to create two oxygen molecules

after each reaction Cl begins the cycle again with another ozone molecule

Cl can therefore destroy throusands of ozone molecule

48
Q

write the reaction steps of how Cl destroys ozone

A
  1. Cl* + O3 -> ClO + O2
  2. ClO + O* -> Cl* + O2
  3. O2 + O* -> 2O2
49
Q

how do you find the mass concentration

A

Ri = Mi / V (kg/m3)

50
Q

how do you find the molar concentration

A

moles per unit volume (mol/m3)

51
Q

how do you calculate number concentration

A

Ci = ni / v (1/m3)

52
Q

how do you calculate number concentration

A

Fi = Vi / V (m3/m3)

53
Q

1ppb = ?ppt

A

1000ppt

54
Q

what is the conversion factor between a mass fraction of 1 ppb and a mole fraction of 1 ppb for CFC-11

A

4.7

55
Q

what are 2 greenhouse gases

A

co2 and Ch4

56
Q

what is the greenhouse effect

A

occurs when gases in Earth’s atmosphere trap the Sun’s heat.