Obtaining Potable Water Flashcards
state why humans use the Earth’s resources
to provide warmth, shelter, food and transport
explain natural resources
supplemented by agriculture, provide food, timber, clothing and fuels
explain finite resources
finite resources from the Earth, oceans and atmosphere are processed to provide energy and materials
describe the importance of water in everyday life
for humans, drinking water should have sufficiently low levels of dissolved salts and microbes
describe potable water and why it is not pure
water that is safe to drink
potable water is not pure water because it contains dissolved substances
state how most potable water is produced
- choosing an appropriate source of fresh water
- passing the water through filter beds
- sterilising
state how to produce potable water if supplies of fresh water are limited
desalination of salty water or sea may be required
- desalination can be dome by distillation or processes that use membranes such as reverse osmosis.
these processes require large amounts of energy
state what sewage and agricultural waste water require removal of
organic matter and harmful microbes
state what industrial waste water require removal of
organic matter and harmful chemicals
describe sewage treatment
- screening and grit removal
- sedimentation to produce sewage sludge and effluent
- anaerobic digestion of sewage sludge
- aerobic biological treatment of effluent
describe the use of phytomining and bioleaching
the Earth’s resources of metal ores are limited
copper ores are becoming scarce and new ways of extracting copper from low-grade ores include phytomining and bioleaching
these methods avoid traditional mining methods of digging, moving and disposing of large amount of rock
explain the process of bioleaching
uses bacteria to produce leachate solutions that contain metal compounds
explain the process of phytomining
uses plants to absorb metal compounds. the plants are harvested and then burned to produce ash that contains metal compounds
