Paper 2 (10) Flashcards
What is the purpose of a life cycle assessment (LCA)?
To assess the environmental impact of products
What the correct order for the stages of a life cycle assessment?
1) Extracting and processing the raw materials
2) Manufacturing and packaging the product
3) Using the product
4) Disposing of the product
Give two ways in which ‘extracting and processing the raw materials’ can damage the environment.
-> Cutting down trees
-> Digging of mines
-> Carbon dioxide production from energy use.
-> Release of pollutants into the environment
Life Cycle Assessments only consider the e___________ impacts, not the financial impacts.
environmental
Which of the following methods of disposal has the lowest environmental impact?
Landfill
Incineration
Recycling
Recycling
Give 2 limitations of life cycle assessments:
-> It is difficult to gather all of the required data about each step
-> Companies can manipulate their LCAs to look more favourable
-> It is difficult to compare different harms e.g. lung disease vs global warming
What is potable water?
Water that is safe to drink
What are the three criteria for water to be considered potable?
Levels of dissolved substances (e.g. salts) must be fairly low
The pH must be between 6.5 and 8.5
The must be no microorganisms
Where does the UK get most of its potable water from?
Fresh water sources
Give 2 sources of fresh water:
Lakes
Rivers
Aquifers
Surface Water vs Ground Water
Surface water is water that is exposed to the ___. It includes lakes, _______ , and reservoirs.
Ground water is water that is found under the _______, such as in_________.
Surface water is water that is exposed to the air. It includes lakes, rivers, and reservoirs.
Ground water is water that is found under the ground, such as in aquifers.
What are the benefits of relying on fresh water?
It is replaced frequently
It is easy to access
What are the three stages of treating fresh water?
1) First, pass the water through a wire mesh. This will filter out any large objects like plastic bottles or leaves.
2) Second, pass the water through a bed of sand and gravel. This will filter out smaller things like bits of rock.
3) Lastly, sterilise the water to kill any microorganisms. There are three different ways to do this: 1) bubbling chlorine gas through it, 2) exposing it to ozone, 3) exposing it to ultraviolet radiation.
What is desalination?
The extraction of potable water from sea water
What is the main drawback of using desalination to get potable water?
It requires a lot of energy, so is very expensive (and contributes to global warming)
What are the two main techniques used in the process of desalination?
Reverse osmosis
Simple distillation
Is nutrient run-off from fields an example of domestic, agricultural, or industrial waste?
Agricultural
Is used shower water an example of domestic, agricultural, or industrial waste?
Domestic
Are the chemicals released from manufacturing factories an example of domestic, agricultural, or industrial waste?
Industrial
True or false? Waste water is usually returned to the environment without processing.
False
Waste water should always be processed before entering the environment to minimise pollution.
Give two things which are removed from sewage and agricultural waste water before the water is returned to the environment.
Harmful microbes
Organic matter
What are the 4 steps in the treatment of sewage?
Screening
Sedimentation
Aerobic digestion
Anaerobic digestion
Steps in the treatment of sewage
1) Screening - The sewage is passed through g_______ and meshes to remove anything l____.
2) Sedimentation - The sewage is left to sit in a settlement tank, so that the heavier p_________ settle at the bottom as sludge, while the lighter particles settle at the top as e_______.
3) Aerobic digestion - Air is pumped through the effluent to supply the bacteria with o______.
4) Anaerobic digestion - The sludge is s______ in a container to prevent the entry of air, which ensures anaerobic respiration.
gratings
large
particles
effluent
oxygen
sealed
Which gaseous product does the anaerobic digestion of sludge produce?
Methane
True or false? Anaerobic digestion of sludge results in fertiliser that be spread on fields.
True
The product that is left over is very nutrient rich, so can be used as a fertiliser.
