Using resources

• humans use Earth's resources for:

  • warmth
  • shelter
  • food
  • transport
• natural resources provide for

  • agriculture
  • food
  • clothing
  • fuel
• finite resources from the earth are being used at a faster rate than they can be replaced
• finite sources from the earth, oceans and atmosphere provides energy and materials
• renewable resources are produced at the same rate as it is being used
• drinking water should have low levels of dissolved salts
• potable water is water that is safe to drink
• methods to produce potable water depend on:

  • location
  • available supply of water
• rain provides water with low levels of dissolved substances
• rain is collected in the ground, in lakes and rivers
• most potable water is produced by:

  • choosing appropriate source of fresh water
  • passing water through filter beds
  • sterilising
• sterilising agents used for potable water include:

  • chlorine
  • ozone
  • UV light
• the desalination of sea water is needed if fresh water supplies is limited
• desalination is the process of removing salt from seawater through distillation
• large amounts of waste water is produced from urban lifestyles and industrial processes
• sewage and agricultural waste need to remove organic matter and pathogens
• sewage treatment methods:

  • screening and grit removal
  • sedimentation, which produces sewer sludge
  • anaerobic digestion of sewage sludge
  • aerobic biological treatment
• metal ores are limited
• copper ores are becoming scarce
• Phytomining and bioleaching are ways to extract copper
• phytomining grows plants that contain copper
• plants grown by phytomining are burned to produce ash, this ash contains metal compounds
• bioleaching converts copper compounds into soluble copper compounds
• copper can be obtained from copper compound solutions through electrolysis
• life cycle assessments are carried out to assess the environmental impact of products
• life cycle assessments are carried out when:

  • extracting and processing raw materials for a product
  • manufacturing and packaging of a product
  • during the products use
  • disposing the product at the end of its life
• the raw materials of a plastic bag is crude oil
• crude oil for a plastic bag is extracted by fractional distillation. as crude oil is useful, wastage is reduced
• plastic bags can be reused
• plastic bags take up landfill space and can pollute the land
• some plastic bags are recyclable
• plastic bags are not biodegradable
• biodegradable is when something can be broken down by bacteria, avoiding pollution
• paper bags are made of timber
• there is lots of waste made when producing paper bags as it uses a lot of energy
• paper bags are usually used once
• paper bags are non toxic and can be recycled
• metals, glass, building materials, clay and plastic are produced from limited raw materials
• obtaining raw materials from the earth causes environmental impacts
• glass bottles can be reused