- Why is water aerated? How may aeration indirectly lead to the removal of colloidal
solids from water? What is the latter process called? - Explain the seemingly contradictory statement that “calcium is used to remove
calcium from water.” - Why is chlorine added to drinking water? Name a “somewhat greener” alternative to
chlorine in this application. Name a “much greener” alternative. - What is meant by sequential use of water?
- Describe reverse osmosis? What kinds of impurities does it remove from water?
- For what purpose is the activated sludge process used? Describe how the process
works.
Chap. 7. Water, The Ultimate Green Solvent 193