Topic 14 - The Earth's Resources Flashcards
What are renewable resources?
Resources that can be re-used indefinitely.
What are finite resources?
Resources that cannot be re-used forever.
What are some examples of finite resources?
-Metal ores are usd to extract metals.
-Crude oil is used to make polymers and petrochemicals.
-Limestone is used to make cement and concrete.
-Crude oil is used to make petrol diesel and kerosene that we use for transport.
What are some examples of renewable resources?
-Wood is used to as furniture and for house building.
-Biofuels are used to power some of the generators producing our electricity.
What is potable water?
Water that is safe to drink.
What does potable water contain?
-Dissolved salts
-Microbes
What does pure water contain?
Only H20 atoms, without any dissolved salts.
How do we obtain potable water?
Rainwater dissolves some gases from the air as it fall to the ground.
Rainwater collects:
-underground
-in lakes
-in rivers
and is called fresh water.
This needs to be filtered for solids like dirt and to remove microbes.
How is sewage filtered?
Sewage and agricultural waste water requires the removal of:
-organic matter
-harmful microbes
What processes are there in sewage treatment?
1) Screening and grit removal
2) Sedimentation - to produce sewage, sludge and effluent - sludge moves to the bottom of the tank.
3) Anaerobic digestion of sewage and sludge, by microbes.
4) Aerobic biological treatment of effluent, by microbes.
Where are most metals found?
Underground
What equipment is needed for the water purification practical?
-Water samples
-Universal indicator
-Bunsen burner
-10cm3 measuring cylinder
-Tripod
-Gauze
-Heatproof mat
-250 cm3 beaker
-Watch glass
-Tongs
-Clamp stand
-250cm3 conical flask
-Delivery tube with bung
-Ice
How are most metals extracted from the Earth?
Smelting or using acid
Why is hydrogen not generally used to extract metals?
Metals react with H2 to form Hydroxide.
What is panning?
Separating particles of greater gravity from the soil.
Give three factors that make it economically viable to extract metal.
-Metals sell for very high prices
-Extraction doesn’t cost a lot
-There is a high demand for metals.
What factors are part of Life Cycle Assessments?
-Extract and process raw materials
-Manufacturing and packaging
-Use and reuse
-Dispose
What is a Life Cycle Assessments?
It works out the environmental impact of each stage of a product’s life.
What are the problems with Life Cycle Assessments?
Its difficult to quantify as it is mainly opinion based.
What can wool be replaced with?
Acrylic fiber
What can cotton be replaced with?
Polyester
What can silk be replaced with?
Nylon
What can linseed oil be replaced by?
acrylic resin
What can rubber be replaced with?
Synthetic polymers
What can wood be replaced by?
PVC, composites
What finite resources do you need to know for GCSE?
Metal ores used to extract metals
Crude oil used to make polymers and petrochemicals
Limestone to make cement and concrete
Crude oil to make the petrol, diesel and kerosene that we use for transport
What are the steps we need to take with cleaning water?
Passing the untreated water through filter beds made of sand and gravel to remove solid particles
The addition of chlorine or ozone to sterilise the water by killing microorganisms
Where is desalination used? Why is this?
Warm and dry countries like in the Middle East as they have little fresh water and thus need to purify salt water.
What are the steps in sewage treatment?
Screening
Primary sedimentation
Biological treatment
Secondary sedimentation + sludge digestion
What can sewage sludge be used for?
The breakdown products include biogas or methane or used to generate electricity
How is sludge treatment?
Treatment is carried out at about 55 degrees at a high or 35 degrees at a low.
What two ways are there to obtain copper metal from its ore?
Using sulfuric acid to make copper sulfate before extracting copper
Smelting copper ore
How do you extract copper from malachite?
Heat the copper carbonate, allowing thermal decomposition to take place.
Add sulfuric acid to copper oxide. Filter black copper oxide.
What two low-grade ore techniques are there?
Bioleaching
Phytomining
What does bioleaching involve?
Bacteria feed on low-grade metal ores to form copper.
What does phytomining involve?
Plants are used to extract copper by absorbing compounds.
These plants are then burned and copper is extracted.
What do LCAs assess?
Getting and processing raw materials
Making the product
Using, reusing and maintaining the product
Disposing of a product
How is an LCA carried out?
Listing all energy and material inputs and all the outputs into the environment
Evaluating the potential environmental impacts from these inouts and outputs
Interpreting the results to help make decisions about using one material, process, product or service over another
How can an LCA be summarised?
Raw material extraction –> manufacture –> Use/reuse –> Maintenance –> Recycle/Waste management
What is the order of recycling aluminium?
Feed conveyor –> shredder –> decoater –> melting furnace –> tilting holding furnace –> filtration unit –> direct chill casting unit –> shredder –> ingots
How are iron and steel recycled?
Using blast furnace with non-renewable fuels
How is copper recycled?
High quality copper can be melted or cleaned and reused
What environmental considerations are there for extracting metals?
Forests and habitats are destroyed for quarrying, which also produces noise and light pollution and release many greenhouse gases
