10. Using Resources Flashcards
What are finite resources?
Those that are being used up at a faster rate than they can be replaced
Examples of finite resources?
- oil
- coal
- gas
- gold
- helium
What are renewable resources?
Those that can be replaced at the same rate at which they are used up
Examples of renewable resources?
- biofuel
- tidal energy
- wind energy
- wood
- geothermal
- hydroelectric
- cotton
What is sustainability?
Developments that meet the needs of today’s society, without endangering the ability of the future generations to meet their needs
How long does wood take to form?
10 years
How long does cotton take to form?
120-180 days
How long does coal take to form?
10 to the power of 6 years
What is wool used for?
Clothes, carpets
What is cotton used for?
Clothes, textiles
What is silk used for?
Clothes
What is linseed oil used for?
Paint
What is rubber used for?
Tyres
What is wood used for?
Construction
What is an alternative synthetic product to wool?
Acrylic fibre (polypropene)
What is an alternative synthetic product to cotton?
Polyester
What is an alternative synthetic product to silk?
Nylon
What is an alternative synthetic product to linseed oil?
Acrylic resin
What is an alternative synthetic product to rubber?
Various synthetic polymers e.g. polybutadiene
What is an alternative synthetic product to wood?
PVC composites (MDF)
Where do dissolved substances in rainwater come from?
As water reaches land it will dissolve substances it comes into contact with such as microorganisms from rocks and soil
How does rainwater become acidic?
The rainwater will dissolve gases from the atmosphere such as CO2 and nitrogen dioxide which will make it acidic
What is potable water?
Water that is safe enough to drink without it causing any health problems
How is rainwater made potable?
- water passed through filter made of sand and gravel - remove insoluble particles e.g. mud
- passed through screen of crossed metal bars to stop large objects e.g. twigs
- left in settlement tank where sand and grit sink
- aluminium sulphate added - smaller particles clump together and sink
- larger particles removed
- sterilise - microorganisms are removed using chlorine and ozone
- pH corrected to neutral
What is used to sterilise rainwater?
Chlorine and ozone
How is sea water made potable?
Desalination
What are the methods of desalination?
Distillation and reverse osmosis
How is water desalinated using distillation?
- water is heated and evaporates, leaving dissolved salts behind
- water then cooled, condensed and collected
Advantages of using distillation to desalinate sea water?
In hot countries solar power can heat the water
Disadvantages of using distillation to desalinate sea water?
High energy costs to heat water
How is water desalinated using reverse osmosis?
- water placed under pressure to overcome natural osmotic pressure
- water passes through semipermeable membrane, leaving the solute behind
Advantages of using reverse osmosis to desalinate sea water?
No heating required
Disadvantages of using reverse osmosis to desalinate sea water?
Energy needed to apply pressure
Salt water corrodes the pumps
What are the sources of sewage?
- toilets
- bath/shower water
- washing machines
- dishwashers
- agriculture e.g. hydroponics
Where does sewage water go?
To sewage treatment plants to make it safe before it can be returned to the environment, usually into rivers or the sea
What is the process of treating sewage water?
- screened to remove large bits (twigs) and grit
- sedimentation - heavier solids sink to the bottom to produce sediment
- effluent floats on top
- effluent removed and treated by aerobic digestion
- sediment broken down by anaerobic digestion - producing methane which can be used as an energy source
What is effluent?
Liquid waste
What is aerobic digestion?
Where bacteria break down any organic matter
What is anaerobic digestion?
A series of biological processes in which microorganisms break down biodegradable material in the absence of oxygen
What does anaerobic digestion produce?
Methane gas which can be used as an energy source
Advantages of treating sewage over desalination?
- use methane for energy
- use fertiliser afterwards
- use less energy
Disadvantages of treating sewage over desalination?
People don’t like the idea of drinking water that used to be sewage
What is a metal ore?
Ores are naturally occurring rocks that contain enough metal or metal compounds to make it economical to extract them
What metals are said to be found native?
The least reactive ones e.g. silver, gold, platinum
What is malachite?
A copper ore containing copper carbonate
How is copper oxide produced from copper ore?
Thermal decomposition (smelting)
What is smelting?
Thermal decomposition
What is phytomining?
When plants absorb copper compounds through their roots and concentrate these compounds as a result. Plants can be burned to produce an ash that contains the copper compounds
Advantages of phytomining?
- low cost
- plants can be easily monitored
- possibility of recovery and reuse of valuable metals
- potentially least harmful method because it uses natural occurring organisms
Disadvantages of phytomining?
- limited to the surface area and depth occupied by the roots
- slow growth and low biomass require a long term commitment
- survival of plants is affected by toxicity of contaminated land and condition of soil
- contaminants into the plants can be passed on in food chain - so requires safe disposal