5.3 Water Purification and Water Supply

• Water purification methods

  • Boiling (To kill microorganisms)
  • Chlorination (To kill microorganisms)
  • Filtration (To separate suspended particles from liquid)
  • Distillation (To separate suspended particles, dissolved substances and kill microorganisms)
• Filtration

  • Removes large suspended particles such as tree branches and leaves
• Oxidation

  • INcreases oxygen content in the water to get rid of unpleasant smell and taste
• Coagulation

  • Alum is added so that mud particles stick together and sink to the bottom of the tank
  • Slaked lime (calcium hydroxide) is added to reduce the acidity of water
• Sedimentation

  • Suspended particles deposit at the bottom of the tank
• Filtration

  • Removes remaining suspended particles through sand filters
• Chlorination and fluoridation

  • Chlorine is added to kill microorganisms in water
  • Sodium fluoride is added to prevent tooth decay
• WATER PURIFICATION PROCESS

  1. Filtration
  2. Oxidation
  3. Coagulation
  4. Sedimentation
  5. Filtration
  6. Chlorination and fluoridation
• Domestic waste

  • Upgrade sewerage systems nationwide
  • Educate people on how to manage rubbish correctly
  • Improve sanitation facilities in rural areas
• Industrial waste

  • Enforce laws to ensure industrial waste is treated before being discharged into the river. Examples of laws on water pollution:
  • Environmental Quality (Scheduled Wates) Regulations 2005
  • Environmental Quality (Industrial Effluent) Regulations 2009
  • Environmental Quality (Sewage) Regulations 2009
• Chemicals in agriculture

  • Educate farmers to use biodegradable fertilisers and pesticides
• Oil spillage

  • Surround and contain oil spilled at sea using National Oil Spill Contingency Plan Revised Year 1999/2000
  • Improve air surveillance with the cooperation of Air-Police Unit