Using Earths resources

• Sustainable development = meeting the needs of current generations without compromising the needs of future generations
• Quarrying: Destroys wildlife , polluted water , noise pollution , releases gas , decreases value of houses
• Potable water = water that is safe for human consumption. It has low levels of dissolved salts and microbes
• Ways to clean ground water:

  1)Sedimentation - particles are separated out

  2)Mesh - removes large insoluble particles

  3)Filtration - removes small insoluble particles

  4)Sterilisation(UV,Ozone,Chlorine) - Kills microbes
• Reverse Osmosis = Salty water is put under high pressure and the water molecules pass through semi-permeable membrane and the salt molecules don’t
• Distillation = separates mixtures with different boiling points and separates salt from pure water. It is carried out by evaporation. It is expensive and requires a lot of energy.
• Dissolved solids RP:

  1)Measure mass of empty evaporating basin

  2)add known volume of water sample into basin

  3)Heat basin on heatproof mat until all water has evaporated

  4)reweigh mass

  5)repeat whole process and calculate mean
• Waste water treatment:

  1. Screen to remove grit
  2. Sedimentation separates small solids to the bottom, forming sludge
  3. Sludge is broken down anaerobically(which removes organic matter)for usage in fertiliser and natural gas
  4. Effluent is broken down aerobically(which kills microbes)to be released back into the environment
• The Life Cycle Assessment contains these stages:

  1. Extracting raw materials
  2. Manufacturing and packaging
  3. Use during its life
  4. Disposal
• Phytomining :

  • Plants are grown in soil containing low percentage of copper ore
  • Roots absorb Copper
  • The plant is burnt and releases copper oxide
  • CuO contains high percentage of copper compound - used to obtain metal copper
• Electrolysis :

  • CuO + H2So4 — CuSo4 + H2O
  • CuSo4 + Fe — Cu + FeSo4 (Displacement)
• Corrosion = Metals corrode when they are left in contact with air and water. When iron corrodes, it is called rusting. Rusting is the oxidation reaction of iron with oxygen in the presence of water which produces iron oxide (rust)
• Corrosion of iron reaction :

  • Iron + oxygen + water — Hydrated iron (III) oxide (rust)
  • 4Fe + 3O2 + 2H2O — 2Fe2O3 . H2O
• To prevent corrosion you can use :

  • Sacrificial protection = a more reactive metal reacts with the oxygen to protect other metal
  • Coatings = Coat the metal with paint to stop it contacting the water
• Harber Process = The reversible reaction between Nitrogen and hydrogen to make Ammonia

  
• Fertilisers :

  • Ammonium hydroxide (NH4OH) + Nitric Acid (HNO3) — Ammonium Nitrate (NH4NO3)
  • Ammonium Hydroxide (NH4OH) + Sulfuric acid (H2SO4) — Ammonium Sulfate (NH4)2 SO4
  • Ammonium Hydroxide (NH4OH) + Phosphoric acid (H3PO4) — Ammonium Phosphate (NH4)3 PO4
• • Soda-lime glass = Sand + limestone + Soda . These are heated at 1500 degrees C .
  • These bonds are covalent and ionic and are not a regular pattern therefore it is brittle
• • Borosilicate = Sand + Boron Trioxide
  • Higher melting point than soda-lime glass
  • Used in ovenware and lab equipment
• Ceramics :

  1. Wet clay
  2. Mold into shape
  3. Heat in furnace

  • Hard , brittle , unreactive , insulators
• Composites = A compound of at least two different types of material .

  • The properties depend on a combination of the materials combined together
  • Most composites are made of a MATRIX of one material surroundings fibres or fragments of another material - process called reinforcements
• Fibre glass :

  • Can be woven into a mat and then embedded in polymer resin . This makes a tough waterproof material with low density - ideal for kayaks and small boats
• Wood = a natural composite

  • plywood - thin layers held together with glue
  • MDF - wood chips compressed and held together with glue
• Fresh water sources are the easiest way to obtain potable water. This is because they only need filtering and sterilising.
• What is the most expensive way of treating water?

  Using sea water is the most expensive way of getting potable water is it requires a lot of energy to desalinate the water.
• Waste water treatment involves the most steps to obtain potable water