c14 - earth's resources Flashcards
give an alterantive sythetic product for wool
acrylic fibre, polypropene
give an alterantive sythetic product for cotton
polyester, nylon
give an alterantive sythetic product for rubber
synthetic polymer
give an alterantive sythetic product for wood
PVC, composite
define finite
being used up at a faster rate than they can be replaces
define renewable
being replaced at same rate at which used up
how are natural resources used to make new products?
- crude oil to make polymers and petrochemicals
- limestone to make cement and concrete
define sustainability
developments that meets the needs of society now, without endangering the ability of future generations to meet their needs.
define potable water
- drinking water
- contains dissolved substances
how can you test for pure water?
- measure boiling points
how does reverse osmosis work?
removes salt and purifies water by using membranes to separate the water from the salts dissolved in it
what is sewage?
waste water from homes, businesses and industry
what is the process for sewage treatment?
1) screening
2) primary sedimentation
3) secondary biological treatment (effluent)
4) secondary sedimentation
5) disinfection
what happens during screening?
removes large solids that won’t otherwise break down
what happens during primary sedimentation?
settling of particulates to make sludge
what is sludge used for?
- fertiliser
- biogas
- generates electricity
- bi-product of the sewage treatment process
what happens during secondary ‘biological’ treatment?
- useful bacteria feeds on remaining organic matter and harmful microorganisms (added to sludge)
- these are broken down in the presence of oxygen (aerobically)
- becomes effluent
how can water be disinfected/ sterilised?
chlorine, ozone, UV light
how is copper produced from copper rich ores?
smelting
- causes environmental polluction
- expensive
- uses huge amounts of energy
how is copper produced from copper poor ores?
- bioleaching
- phytomining
define the process of phytomining
- plants are grown on soil and absorb copper ions
- plants are then burned and copper is extracted from the ash
define the process of bioleaching
- bacteria produces leachate solution
- scrap iron is added to leachate to displace it
why is it less preferred to use electrolysis?
- high amount of energy needed
- more expensive
state the 5 main stages of an LCA
1) Extraction
2) Manufacture
3) Distribution
4) Use/management
5) Recycling/disposal
why should an LCA be peer reviewed?
- check data and validity of conclusions drawn
- especially important if results are used in marketing
what is the aim of ‘reduce reuse and recycle’?
- reduce energy
- reduce landfill
- reduce mining
what is a main downside of recycling?
requires energy so it is preferrable to reuse as well
how is iron ore conserved?
steel scrap is added to blast furnace
how is metal recycled?
melting
why is it important to recycle metals?
processes to extract metals are harsh on environment e.g cause acid rain, global warming
