Resources

• Agriculture produces most of the resources we use
• Cotton is produced from a plant
• plants can be used timber or fuel
• agriculture helps us to use the earths resources more efficiently
• rubber is made from the sap of tree
• Synthetic rubber is produced using crude oil, around 2/3 of rubber is synthetic
• Natural resources are finite
• Finite resource = they cannot be replaced as quickly as they are being used
• Fossil fuels Is a finite resource
• Metal is a finite resource
• huge amounts of metal is extracted from the earths crust
• Wood is renewable
• Renewable = never run out
• Artificial fertilisers allow us to grow more food with land available
• Phytomining and bioleaching help extract metals more efficiently
• Potable water is drinking water
• Pure water contains no dissolved solids
• Pure water is neutral
• Potable water contains dissolved solids
• What is the first step in sewage treatment?

  Sewage is screened through a mesh
• What does screening sewage remove?

  Solids and pieces of grit
• What happens to sewage in sedimentation tanks?

  It produces liquid effluent and semi-solid sludge
• What is done with the sludge after sedimentation?

  It is taken away and digested by anaerobic bacteria
• What do anaerobic bacteria produce during digestion of sludge?

  Biogas
• How can biogas produced from sludge be used?

  It can be burned for electricity
• What can digested sludge be used for?

  Fertilizers for farming
• What does liquid effluent contain that is harmful?

  Large amounts of organic molecules and harmful microorganisms
• What is done to liquid effluent to promote bacterial growth?

  Air is bubbled through it
• What do aerobic bacteria do in the presence of oxygen?

  They digest organic molecules and harmful microorganisms
• What can be done with liquid effluent after treatment?

  It can be discharged to rivers or sea
• What is the easiest way to produce potable water?

  Use groundwater from aquifers
• What is a potential issue with aquifers?

  They can be polluted with fertilizers
• What must be done to water from aquifers before use?

  It needs to be tested carefully
• What does desalination produce?

  Potable water
• What are the drawbacks of desalination?

  It requires a lot of energy and is expensive
• What is a metal ore?

  Contains enough metal to extract economically
• What are the steps of phytomining?

  1. Grow plants on land with metal compounds
  2. Plants absorb and concentrate the metal
  3. Harvest and burn the plants
  4. Ash contains high metal concentration
• What are the steps of bioleaching?

  1. Mix bacteria with lower grade ore
  2. Bacteria carry out chemical reactions
  3. Produce a solution called leachate
  4. Leachate contains the desired metal compound
• What happens at the end of phytomining and bioleaching?

  The metal compound is extracted from low-grade ore
• How is metal extracted from metal compounds?

  Displace with a more reactive metal and use electrolysis