Using Resources Flashcards
What are the sterilising agents for potable water?
Chlorine, ozone or ultraviolet light
Chlorine - toxic gas so amount must be monitored
UV - avoids adding chemicals but is more expensive
How is desalination carried out?
Can be done by distillation or reverse osmosis
What is reverse osmosis?
Sea water is passed through a membrane that only allows molecules through the water
It needs high pressure to push water through the membrane
How is waste water produced and how is it treated?
Urban lifestyle and industrial processes produce large amounts of waste water
Sewage and agricultural waste water require the removal of organic matter and harmful microbes
Industrial waste water may require the removal of organic matter and harmful chemicals
What are the processes involved in sewage treatment?
Screening and grit removal
Sedimentation to produce sewage sludge and effluent
Anaerobic digestion of sewage sludge
Aerobic biological treatment of effluent
What is phytomining?
Uses plants to absorb metal compounds from the soil
The plants are harvested and then burned to produce ash that contains the metal compounds
What is bioleaching?
Uses bacteria to produce leachate solutions that contain metal compounds
What are the advantages and disadvantages of phytomining and bioleaching?
Adv - need less energy than traditional methods and can work on low concentration ores
Dis - slow to carry out
Describe the stages of the life cycle assesment:
Extracting and processing raw materials
Manufacturing and packaging
Use and operation during its lifetime
Disposal
What are the advantages and disadvantages of recycling?
Adv - less acid rain, less waste
Dis - collection and transport problems, cost of transport and separation
Uses of bronze:
An alloy of copper and tin
Used for making statues
Uses of brass:
An alloy of copper and zinc
Used for producing water taps and door fittings
Uses of gold:
Alloy of silver, copper and zinc
Used for jewellery
Uses of aluminium:
Alloy of magnesium
Used for aerospace
