Using Earth’s resources p2 Flashcards
(25 cards)
what do we use earth’s resources for
to provide us with warmth, fuel, shelter, food, transport
what are natural resources used for
food, timber, clothing, fuels
define synthetic resources
made by scientists
to replace or supplement natural resources
define potable water
water that is safe to drink
what does potable water contain
water molecukes, low levels of salts, safe levels of harmful microbes
what does pure water contain
just water molecules, nothing else
what does sea water contain (salty water)
water molecules, dangerously high levels of salts, can have high levels of harmful microbes
what does fresh water contain + where is it usually found
FOUND IN:
rivers, lakes or underground
CONTAINS:
water molecules, low levels of salts, often has harmful microbes at high levels
How to produce potable water from rain warer (fresh water)
(Collected from lakes and rivers)
- choose an appropriate source of fresh water
- pass water through filters to remove large insoluble objects
- sterilise the water to kill any microbes using ozone, chlorine or UV light
list 3 methods of sterilization
ozone, chlorine, UV light
How to produce potable water from salty water
DESALINATION
(requires a lot of energy)
-distillation
-reverse osmosis
define reverse osmosis and explain why it is expensive
involves using membranes to separate the salts dissolved in the water
water needs to be pressurised and salty water corrodes the oumps
therefore its expensive
Define waste water
waste water produced by human activities as:
-sewage
-agricultural waste
(both contain organic matter and harmful microbes)
-industrial waste
(contains organic matter and harmful chemicals)
DESCRIBE HOW TO TREAT SEWAGE WATER
(before sludge and effluent)
- SCREENING AND GRIT REMOVAL
sewage passes through metal grid to filter out large insoluble objects
2.SEDIMENTATION
sewage left so solid sediments can settle out of the water
-sediments sink to bottom and liquid sits on top
what are the liquid and solid called which are produced after first 2 steps of treating sewage water
sludge (solid) and effluent (liquid)
what does sewage sludge contain
organic matter, water, dissolved compounds, small solid particles
what does effluent contain
no solid matter visible but still contains some matter and harmful microorganisms
how to treat sewage sludge
- anaerobic treatment
bacteria added to digest organic matter anaerobically
2.biogas
anaerobic digestion produces biogas
(mixture of methane, co2, hydrogen)
can be used as fuel
3.remaining sludge
can be dried out and burnt to be used as fuel
how to treat effluent
1.aerobic treatment
bacteria added to feed on organic matter and microorganisms
2.bacteria removed
bacteria allowed to settle out of water
- discharged back to river
water now safe enough to be released back into environment
name the 2 methods of metal extraction
phytomining and bioleaching
Describe the process or phytomining
(used to extract copper from lore grade ores)
1.grow plants near metal ore
2.harvest and burn the plants
3.the ash contains metal compound
4.process the ash by electrolysis/displacement with scrap metal
Describe the process of bioleaching
(used to extract copper from low grade ores)
1.grow bacteria near metal ore
2.bacteria produce leachate solutions that contain metal compound
3.process leachate by electrolysis/displacement with scrap metal
what are the 4 categories of anlife cycle assessment
- extracting and processing raw materials
- manufacturing and packaging
- use and operation during its lifetime
- disposal at the end of its useful life, including transport and distribution at each stage
name 4 ways to dispose of products
- add to landfill
(some items will persist here as they do not biodegrade) - incinerate
(may release harmful pollutants into atmosphere) - reuse
- recycle
(requires energy but less than would be required to make new materials)
