using resources (p2) Flashcards
What are finite resources?
Resources that aren’t formed quickly enough to be considered replaceable
What are renewable resources?
Resources that reform at a similar rate to, or faster than they are used
What are natural resources?
Resources that form without human input
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 is potable water?
Water that is safe to drink
What is desalination?
The removal of salt from water
Is potable water pure?
No - it contains dissolved substances
Outline the three steps in producing potable water from fresh water
- Choose a source of fresh water
- Passing water through filter beds
- Sterilising it
What is the main source of fresh water in the UK?
Rain water that collects in the ground and in rivers and lakes
Why is fresh water passed through filter beds when making potable water?
To remove any solid material
Why is fresh water sterilised when making potable water?
To kill microbes
If supplies of fresh water are limited, how will potable water be generated?
Desalination of salt water or sea water
How is salty water desalinated?
Either by distillation or reverse osmosis (both process remove salt)
Why is it better to generate potable water from fresh water than salty water?
Desalination of salty water requires lots of energy
How can fresh water be sterilised?
Either by chlorine, ozone or UV light
How can you test if water is pure?
Check the melting and boiling point: pure water melts at 0 ᵒC and boils at 100 ᵒC
Outline the process of sedimentation during waste treatment
- Sewage water stands in a settlement tank
- Heavy solids sink to the bottom to produce sludge
- Light effluent floats on the top
How is sewage treated?
- Screening to remove any large material
- Sedimentation to produce sludge and effluent
- Sludge undergoes anaerobic digestion to produce natural gas and fertiliser
- Effluent undergoes aerobic digestion to produce water
What happens when sludge undergoes anearobic digestion?
The organic matter in sludge is broken down producing natural gas and fertiliser
What happens when effluent undergoes aerobic digestion?
the organic matter in effluent is broken down producing water
What happens to the water that is produced from the aerobic digestion of effluent?
Released back into the environment
[𝗛𝗶𝗴𝗵𝗲𝗿 𝘁𝗶𝗲𝗿] What is a low grade ore?
An ore that contains only a small amount of the required metal
[𝗛𝗶𝗴𝗵𝗲𝗿 𝘁𝗶𝗲𝗿] What is an ore?
A naturally occuring compound from which a metal can be extracted
[𝗛𝗶𝗴𝗵𝗲𝗿 𝘁𝗶𝗲𝗿] Name two methods used to extract copper from low-grade copper ores
Phytomining
Bioleaching
[𝗛𝗶𝗴𝗵𝗲𝗿 𝘁𝗶𝗲𝗿] Describe the process of phytomining
- Plants absorb copper compounds from the soil containing low grade copper ore
- The plants are harvested and burned to produce ash that contains copper compounds
[𝗛𝗶𝗴𝗵𝗲𝗿 𝘁𝗶𝗲𝗿] Describe the process of bioleaching
- Bacteria feed on copper compounds in low grade copper ores
- Bacteria produce leachate that contains copper compounds
[𝗛𝗶𝗴𝗵𝗲𝗿 𝘁𝗶𝗲𝗿] What is leachate?
A solution of soluble copper compounds
[𝗛𝗶𝗴𝗵𝗲𝗿 𝘁𝗶𝗲𝗿] How is copper extracted from the soluble copper compounds produced in bioleaching and phytomining?
Either by electrolysis or displacement reactions using scrap iron
[𝗛𝗶𝗴𝗵𝗲𝗿 𝘁𝗶𝗲𝗿] What are the advantages of obtaining copper from bioleaching or phytomining instead of traditional mining?
Phytomining and bioleaching do not involve digging, moving and disposing large amounts of rock
Why are life cycle assessments carried out?
To assess the environmental impact of the life of a product
What are the main stages of a life cycle assessment?
consider the environmental impact of products during:
* extracting and processing raw materials
* manufacturing and packaging
* use and operation during its lifetime
* disposal at the end of its useful life, including transport and distribution at each stage.
