Fill in each blank with the correct word from the lesson.

1. _______ kills remaining pathogens.
2. A sewage treatment plant transforms dirty _______ into water clean enough to be safely released into rivers or the sea.
3. Without _______ plants, our rivers, lakes, and coastal waters would be hopelessly polluted.
4. This biological _______ takes several hours.
5. Treated water is safe to release into the env_______ment.

Choose the best option for each question.

1. What does the screening step in sewage treatment remove?
   a) Bacteria and virusesb) Dissolved chemicalsc) Large solid objects like rags and plasticd) Excess nutrients
2. What is the purpose of aeration in sewage treatment?
   a) Adding oxygen to drinkb) Bacteria break down dissolved organic wastec) Filtering out heavy metalsd) Removing suspended particles by settling
3. How is water disinfected at the end of sewage treatment?
   a) Boilingb) Adding saltc) Chlorination or UV lightd) Reverse osmosis

Write T for True or F for False in the brackets.

1. Large solid objects like rags and plastic is one of the key concepts in the lesson on Wastewater Treatment.
2. Bacteria and viruses is the main topic of this lesson.
3. Bacteria break down dissolved organic waste is one of the key concepts in the lesson on Wastewater Treatment.
4. Adding oxygen to drink is the main topic of this lesson.

1. In your own words, explain what Wastewater Treatment means.
2. List two things you learned from this lesson on Wastewater Treatment.