1SDS p.102 #1-9, 18-22

1SDS p.102 #1-9, 18-22

1. 

2. Evaporation- removes almost all dissolved subs.

    Bacterial Action- converts organic dissolved contaminants into a few simple compounds.

    Filtration through sand and gravel- removes almost all suspended matter. 

3. The properties of aluminum hydroxide are related to the process of flocculation because aluminum reacts with alum and slake lime which form this. This sticky, jelly like material traps and removes the suspended particles. 

4. Calcium oxide is sometimes added to the final steps of municipal water treatment to neutralize acidic water, raising it to its proper pH level. 

5. As much as 1 ppm of fluoride is added to reduce tooth decay. 

6. Advantages of chlorinated drinking water compared to untreated water are killing disease organisms in water. This saves many lives and is essential. 

7. There is a disadvantage to using chlorination in water treatment because in high concentrations, it can be harmful to humans, causing death through reactions with organic compounds. 

8. Water from a clear mountain stream may require chlorination to make it safe for drinking because the stream may contain bacteria or diseases that may cause death or sickness. 

9. Two alternatives to the use of chlorination in municipal water treatment are charcoal filtration or using ozone or ultra violet light to disinfect the water. 

18. If water evaporation suddenly stopped, it would stop many other steps of the hydrologic cycle. Without the crucial step of evaporation, the whole cycle would stop. 

19. The hydrologic cycle would be different if this were not true because the hydrologic cycle includes all 3 states, and without the three states, the hydrologic cycle would just stop.

20. The EPA recognizes that there are alternatives to eliminating such as limiting because the eliminating can cause THM health risks. 

21. Evaporation and condensation are similar to the steps used in the foul water lab. Also, water passing through the gravel, sand, and rock is also similar to sand filtration. 

22. a. 1 ppm fluoride

      b. 7 ppm fluoride

      c. 365 ppm fluoride