chemistry 10

• what are the steps in a life cycle assessment? 


  raw materials

  manufacturing and packaging

  using the product

  disposal
• what is potable water?

  water treated so that it is safe to drink
• where is water collected from?

  groundwater

  surface water
• what process do fresh water sources undertake?

  filtration- a wire mesh screens out solids

  sterilisation- kill harmful microbes or bacteria using chlorine or uv light
• what are the stages of sewage treatment? 


  1 screening water is filtered to remove solids

  2 sedimentation allowed to sit the heavier solids sink to bottom and make sludge effluent floats at top

  3 effluent is removed and treated by aerobic digestion

  4 sludge is removed and broken down using anaerobic respiration

  (bacteria)