Earth's Resources Flashcards
What are Earth’s resources used for?
Warmth, fuel, food, shelter, transport
What is it important to consider when choosing and synthesising resources?
Sustainable development
What is sustainable development?
Meets the needs of current generations without compromising the ability of future generations to meet their own needs
What are finite resources?
Resources that will eventually run out
What are renewable resources?
Resources that will not run out
What is potable water?
Water that is safe to drink and contains safe levels of harmful microbes and low levels of salts
What is pure water?
Water that just contains water molecules
What is fresh water?
Water molecules, low levels of salt and often higher levels of harmful microbes
How is potable water produced in the UK?
An appropriate source of fresh water is chosen
Pass through filters to remove large objects
Sterilise the water to kill any microbes using ozone, chlorine or UV light
What is desalination?
The process of turning saltwater into potable water. This requires a lot of energy and is done by distillation or reverse osmosis which involves using membranes to separate the salts dissolved in the water. The water needs to be pressurised and the salt water corrodes the pumps
What is waste water?
Sewage, agricultural waste and industrial waste
Contain organic matter and harmful microbes/ chemicals
These need to be removed
How is sewage water treated?
Screening and grit removal - filters out large objects
Sedimentation - solid sediments settle sink to bottom
Sewage sludge - organic matter, water, dissolved compounds and small solid particles
Anaerobic treatment - bacteria digest organic matter and produce biogas which can be used as fuel
Remaining sludge can be dried out, burned and used as fuel
Effluent contains no solid matter but has harmful microorganisms
Aerobic treatment- bacteria added
Bacteria removed
Water released back to environment
How are metals extracted?
From ores by electrolysis or reduction
Metal ores are finite and require a lot of energyv
What is phytomining?
Grow plants near metal ore
Harvest and burn plants
Ash contains metal compound
Process the ash by electrolysis or displacement with scrap metal
What is bioleaching?
Grow bacteria near the metal ore
Bacteria produce leachate solutions which contain metal compound
Process the leachate by electrolysis or displacement with scrap metal
