Using Earth's resources and potable water (10.1) (M) Flashcards
4 things
Humans use the Earth’s resources to provide… (w, s, f, t)
warmth, shelter, food and transport
4 things
Natural resources, supplemented by agriculture, provide… (f, t, c, f)
food, timber, clothing and fuels
2 things
Finite resources from the Earth, oceans and atmosphere are processed to provide… (e, m)
to provide energy and materials
How does chemistry play an important role in improving agricultural and industrial processes?
By providing new products
And in sustainable development
What is sustainable development?
Development that meets the needs of current generations without compromising the ability of future generations to meet their own needs
What are finite resources?
resources that can only be used once and are in limited supply (e.g. oil)
What are renewable resources?
resources which can be replaced or replenished (while using them), so we won’t run out of them
For sustainable development, what is happening to some natural products?
they are being supplemented or replaced by agricultural and synthetic products
What is an example of natural products that are supplemented or replaced by agricultural and synthetic products?
synthetic fertilisers, with ingredients obtained from the Haber process
What is water of appropriate quality is essential for?
life
For humans, what should drinking water should have sufficiently low levels of?
dissolved salts and microbes
What is water that is safe to drink called?
Potable water
What is pure water?
Water that contains a 100% concentration of H2O molecules
Why is potable water not pure water in the chemical sense?
because it contains dissolved substances e.g. mineral rocks
What do the methods used to produce potable water depend on?
available supplies of water and local conditions
Describe the rain that falls in the UK? (and where is it collected?)
Rain provides water with low levels of dissolved substances (fresh water) that collects in the ground and in lakes and rivers
3 stages + reasons
What is most potable water produced by? (how ground water is treated)
- choosing an appropriate source of fresh water (rain provides water with low levels of dissolved substances)
- passing the water through filter beds (to remove different sized insoluble solids)
- sterilising (to kill microbes)
What do sterilising agents used for potable water include?
chlorine, ozone or ultraviolet light
If supplies of fresh water are limited, what may be required?
the desalination of salty water or sea water
How can desalination be done? (i.e. treatment of salty water process)
By distillation or by processes that use membranes such as reverse osmosis.
These processes require large amounts of energy.
What is the problem with desalination of salty or sea water?
It requires a lot of energy, which is expensive (more so than ground water treatment)
Urban lifestyles and industrial processes produce large amounts of (…) water
Waste water
What does waste water require before being released into the environment?
treatment
What do sewage and agricultural waste water require removal of?
organic matter and harmful microbes
What may industrial waste water require removal of?
organic matter and harmful chemicals
4 stages
Describe the process of sewage treatment
- screening and grit removal
- sedimentation to produce sewage sludge and effluent
- anaerobic digestion of sewage sludge
- aerobic biological treatment of effluent.
Compared with sewage treatment, obtaining potable water from waste, ground and salt water is relatively (…)
easy
The Earth’s resources of metal ores are (…)
limited
What is happening to copper ores?
They are becoming scarce, so are in increasing demand
What are low-grade ores
ores with a low concentration of metal
2 needed
What are the new ways of extracting copper from low-grade ores?
phytomining and bioleaching
How are new ways of copper extraction (phytomining and bioleaching) different from traditional methods?
These methods avoid traditional mining methods of digging, moving and disposing of large amounts of rock.
How is phytomining used to extract copper?
Grow plants
Phytomining uses plants to absorb metal compounds.
The plants are harvested and then burned to produce ash that contains metal compounds
Ash dissolved in acid (to produce a solution of copper compound)
Displacement of copper from solution (containing a copper compound with addition of scrap iron) or electrolysis of copper compound
How is bioleaching used to extract copper?
Bioleaching uses bacteria to produce leachate solutions that contain metal compounds
Electrolysis of leachate solution OR displacement of leachate solultion by adding scrap iron to extract copper
These metal compounds [produced from phytomining and bioleaching] can be (…) to obtain the metal
processed
add this in for explanation of how the process works
How can copper be obtained from solutions of copper compounds?
by displacement using scrap iron or by electrolysis
What is the issue with bioleaching?
it produces toxic substances which need to be treated so they don’t contaminate the environment
What is the issue with phytomining?
burning plant matter is bad for the environment, plants absorb CO2 and burning releases CO2
Why is waste water harder to treat than ground water?
Water needs more processes.
It contains more microbes, more organic matter and toxic chemicals/detergents
Why should the amount of chlorine in a pool be monitored and controlled?
chlorine is toxic
so too much will cause health problems
What is the benefit of using chlorine to make water safe to drink?
Cheap/easy to use
What are ores?
Ores are substances extracted from the Earth’s surface
that contain enough metal to make it economical to extract
Why are alternative methods necessary to extract copper necessary, and how does this affect the sustainability of the process?
copper is a finite resource
using alternative methods to extract copper from low-grade ores
makes this process more sustainable
Processed solid sewage sludge can be used as fertiliser. Why might have the total mass of processed sludge increased recently?
the population increased
The use of processed sludge as fertiliser has increased. Suggest two reasons why this may have been the case
increased demand for food
to conserve energy
How could you test for pure water?
determine boiling point, which should be at a fixed temperature 100oC
