C14
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what are natural resources used for
food, warmth, shelter and transport
what is the use and alternative synthetic product of wool and cotton
wool - clothes, carpets - acrylic fibre cotton - clothes, textiles - polyester, nylon
what is a finite resource
a resource being used up at a faster rate than they can be replenished
what does the chemical industry do with natural resources
use them as the raw materials to make new products for example metal ores used to extract metal crude oil used to make polymers
what is sustainability
developments that meet the needs of society to now, without endangering the ability of future generations to meet their needs
what are two examples of sustainability
polymers produced from ethene - ethanol is produced from sugar cane use of wood chips instead of fossil fuels to fuel power stations
what is potable water
water that is safe to drink
is potable pure water
it is not pure water as it contains dissolved substances
what is fresh water
rainfall collected in rivers and lakes
what does fresh water contain
dissolved minerals. (salts)
how is water treated to make it potable
passing it through filter beds to remove solid particles then sterilised by adding chlorine or ozone
how can sea water or salty water be made potable
desalination
what are disadvantages of desalination
expensive process due to the large energy costs involved in heating salty water
what is sewage
general name for waste water from homes
what does sewage treatment do
removes organic matter and harmful microorganisms
what are the steps of sewage treatment
screening - removes large solid objects and grit from water sedimentation - solid elements settle out from the mixture. aerobic biological treatment - in the effluent useful bacteria feed on any remaining organic matter and harmful microorganisms. this breaks them down aerobically
what is effluent
the watery liquid above the sludge and this still contains many harmful microorganisms
what does sludge contain
organic matter such as - human waste, suspended solids and water
what can sludge be used for after
fertiliser or a source of renewable energy
how is copper produced
from copper rich ores by smelting