Topic 10 - Using resources

• What is sustainable development?

  Development meeting current and future needs
• How is potable water produced in the UK?

  By choosing a fresh water source
• What is the purpose of filter beds in potable water production?

  To remove solids from the water
• Why is sterilization important in potable water production?

  To kill harmful microbes in the water
• What are the sterilising agents for potable water?

  Chlorine, ozone, or ultraviolet light
• Why must chlorine levels be monitored in water treatment?

  Chlorine is a toxic gas
• What is a benefit of using ultraviolet light for sterilization?

  Avoids adding chemicals to the water
• How is desalination carried out?

  By distillation or reverse osmosis
• What is reverse osmosis?

  Passing seawater through a selective membrane
• What is required to push water through a reverse osmosis membrane?

  High pressure is needed
• How is wastewater produced?

  From urban lifestyles and industrial processes
• What types of wastewater require treatment?

  Sewage and agricultural wastewater
• What is removed from sewage during treatment?

  Organic matter and harmful microbes
• What may industrial wastewater require removal of?

  Organic matter and harmful chemicals
• What are the processes involved in sewage treatment?

  • Screening and grit removal
  • Sedimentation to produce sludge and effluent
  • Anaerobic digestion of sewage sludge
  • Aerobic biological treatment of effluent
• What do new mining methods avoid?

  Disadvantages of traditional mining methods
• What is phytomining?

  Using plants to absorb metal compounds
• What is bioleaching?

  Using bacteria to produce leachate solutions
• What is the main advantage of phytomining and bioleaching?

  They need less energy than traditional methods
• What is a disadvantage of phytomining and bioleaching?

  They are slow to carry out
• What are the stages of Life Cycle Assessments (LCAs)?

  1. Extracting and processing raw materials
  2. Manufacturing and packaging
  3. Use and operation during its lifetime
  4. Disposal at the end of its useful life
• How can we reduce the use of resources?

  By reducing, reusing, and recycling materials
• What are the advantages of recycling?

  • Less acid rain
  • Longer metal ore reserves
  • Conserved energy
  • Less mining and waste
  • Creates local employment
• What are the disadvantages of recycling?

  • Collection problems
  • Transport cost issues
  • Difficulty separating metals
• What is corrosion?

  Destruction of materials by chemical reactions
• How can corrosion be prevented?

  By applying a protective coating
• What is sacrificial protection?

  Using a more reactive metal to corrode
• What is bronze made of?

  An alloy of copper and tin
• What is brass made of?

  An alloy of copper and zinc
• How is the purity of gold measured?

  In carats, with pure gold as 24 carat
• What are aluminium-magnesium alloys used for?

  In aerospace manufacturing due to low density
• What are the types of steel and their properties?

  • High carbon steel: strong but brittle
  • Low carbon steel: softer and easily shaped
  • Stainless steels: hard and resistant to corrosion
• How are the properties of polymers determined?

  By their monomers and production conditions
• What are the structures of thermosoftening and thermosetting polymers?

  • Thermosetting: linked by strong cross-links, do not melt
  • Thermosoftening: soften on heating, can be remoulded
• How is glass made?

  By heating sand, sodium carbonate, and limestone
• How are clay ceramics made?

  By shaping wet clay and heating in a furnace
• How are composites formed?

  • Fibres or fragments surrounded by a binder
  • Example: fibreglass, glass fibres in polymer
• What are the key stages of the Haber process?

  1. Purified H2 and N2 over Fe catalyst
  2. Reaction forms ammonia: N2 + 3 H2 ⇌ 2 NH3
  3. Ammonia is liquefied and removed
  4. Remaining gases are recycled
  5. Ammonia used for nitrogen-containing fertilizers
• What is the compromise in the conditions of the Haber process?

  Between rate of reaction and yield
• Why is a temperature of 450 °C used in the Haber process?

  To balance yield and reaction rate