waste water treatment

• What is potable water?

  Water that is safe to drink
• What percentage of water is used for drinking?

  A small percentage
• What are some uses of water besides drinking?

  Personal hygiene, flushing toilets, washing clothes
• What does wastewater contain that makes it harmful?

  Organic molecules and harmful microorganisms
• Why must wastewater be treated before release?

  To remove harmful substances
• What is the first stage of wastewater treatment?

  Sewage is screened through a mesh
• What happens to sewage after screening?

  It settles in large sedimentation tanks
• What is produced after sewage settles in sedimentation tanks?

  Liquid effluent and semi-solid sludge
• What happens to the sludge in wastewater treatment?

  It is digested by anaerobic bacteria
• What do anaerobic bacteria produce from sludge?

  Biogas
• How can biogas produced from sludge be used?

  Burned for electricity
• What must be done to the liquid effluent before discharge?

  Reduce organic molecules and microorganisms
• How is oxygen introduced to the liquid effluent?

  By bubbling air through it
• What type of bacteria digest organic molecules in the effluent?

  Aerobic bacteria
• Where can the treated liquid effluent be safely discharged?

  Into nearby rivers or the sea
• What is a common industrial use of water?

  Making paper and chemicals
• What must be removed from industrial wastewater before treatment?

  Harmful chemicals
• How is treated sewage used in some parts of the world?

  To produce potable water directly
• Why is groundwater from aquifers often used for potable water?

  It is usually safe to drink
• What must be done to aquifer water before drinking?

  It needs to be treated with chlorine
• What can pollute aquifers?

  Fertilizers from farms
• What is required to produce potable water from salt water?

  Desalination
• What is a drawback of desalination?

  It requires a lot of energy
• What is the main challenge of producing potable water from wastewater?

  It requires many purification steps
• How does the treatment of wastewater differ from that of industrial water?

  Industrial water requires chemical removal first
• What is the role of sedimentation tanks in wastewater treatment?

  To allow solids to settle out
• What is the final use of digested sludge?

  Used as fertilizers for farming
• What is the purpose of bubbling air through liquid effluent?

  To promote aerobic bacteria growth
• What happens to harmful microorganisms during wastewater treatment?

  They are digested by bacteria
• What is the significance of testing aquifer water?

  To ensure it is not polluted
• What is the relationship between wastewater treatment and potable water production?

  Wastewater treatment can produce potable water
• Why is it important to treat wastewater before discharge?

  To protect the environment and public health
• What is the main reason for using chlorine in water treatment?

  To kill harmful microorganisms
• What is the role of sedimentation in wastewater treatment?

  To separate solids from liquids
• What is the final step in treating liquid effluent?

  Safe discharge into water bodies
• What is the purpose of using anaerobic bacteria in sludge treatment?

  To break down organic matter without oxygen
• What is the environmental impact of untreated wastewater?

  It can harm ecosystems and public health
• What is the significance of biogas produced from sludge?

  It can be used as a renewable energy source
• How does the treatment of wastewater contribute to sustainability?

  By recycling water and reducing pollution
• What is the importance of monitoring wastewater treatment processes?

  To ensure effectiveness and safety