1. Chapter 1.D.
Water Cycle

2. 1.D. Water Treatment and Purification Do Now
Read pgs Answer the questions:
1. Why do we treat our water?
2. How does the natural hydrological cycle help purify water?
3. Why is chlorine added to the water?
4. What is flocculation?
5. List one addition purification step.

3. Objectives
SWBAT describe the natural hydrologic water cycle and the municipal water treatment cycle.
SWBAT compare and contrast between both cycles.

4. Nature’s Hydrological Cycle

5. Nature’s Hydrological Cycle
Steps that aid in purification:
1. Distillation:
-evaporation of water leaving behind dissolved ions.
2. Aeration:
-water that trickles over rocks allows volatile impurities, previously dissolved, to be released into the air.
-growth of microscopic plant and animal organisms that use certain water contaminants for food and energy. 3. Sedimentation:
-separation of solids particles from slow moving streams
4. Filtration:
-Silt and clay particles removal as water filtrates sandy soil.

6. Did You Know Residence time: How long water stays in one place
In glaciers and ice caps-replaced every yrs
In the atmosphere-replaced every 8 days
Reserviors-1 to 2 months

7. Do Now Get with a partner and draw the hydrological cycle with labels!
Leave your homework on your desk WITH your name on it!

8. Objectives
SWBAT describe the natural hydrologic water cycle and the municipal water treatment cycle.
SWBAT compare and contrast between both cycles.

9. Municipal Pre-Use Water Treatment
Scan in image

10. Municipal Water Treatment
Steps to Water Treatment
1. Screening

11. Steps to Treatment (cont.)
2. Prechlorination
3.Flocculation:

12. Steps to Treatment (cont.)
4. Settling:
5. Sand Filtration:

13. Steps to Treatment (cont.)
6. Postchlorination

14. Optional Further Treatment
Aeration:
pH Adjustment
Fluoridation:

15. Use pages 85-89 to fill in the following chart
Nature’s Cycle
Municipal Treatment
Evaporation
Bacterial Action
Filtration
Other

16. Do Now
List the steps of municipal water treatment.

17. Objectives 1. SWBAT explain why chlorine is added to the water supply.
2. SWBAT explain the relationship between chlorine and cancer.
3. SWBAT compare and contrast bottle vs. tap water perks and problems associated with it.

18. Chlorine in Water supplies
Chlorine is added to the water supply in 3 ways:
Chlorine Gas
Sodium hypochlorite (NaOCl)
Calcium hypochlorite Ca(OCl)2
Most active form of chlorine in water is:
HOCl (hypochlorous acid)

19. Chlorine can form Carcinogens.
Chlorine can react with organic compounds to form trihalomethanes (THMs) such as chloroform. (CHCl3)
Limits the amount of chlorine added to water

20. Chlorination and THMs Charcoal Filter Ozone or UV Light
Eliminate Prechlorination
Advantages
-Remove THMs
Less chlorine
Disadvantages
-Expensive
-Difficult to dispose of
-Does not protect water once it has left the plant
Less chlorine could mean more bacterial growth in water

21. Are these pure, clean and better than ordinary tap water?

22. Bottled Water vs. Tap Water
What are some factors that you should consider in deciding whether to drink bottle or tap water?

23. Hard Water Water containing excessive dissolved: Calcium (Ca2+)
Magnesium (Mg2+)
Iron (III) Fe3+

24. D.8. Water and Water Softening
Affects the cleaning action of soap
Soap can react with hard water ions to form insoluble compounds
Soap Scum
Soap Curds on clothing, skin and hair

25. Hydrogen carbonate ions in Hard water
HCO3- can cause calcium carbonate to form in water
This can build in pipes, hot water heaters, etc.
Takes longer to heat water (Blocks heat flow)

26. Water Softening Remove hard water ions
Adding sodium carbonate (Na2CO3) Washing Soda
Precipitates will be washed away with water

27. Common Water Softening Substances
Borax
Trisodium phosphate
Calgon (hexametaphosphate)

28. Detergents Work like soaps but don’t leave behind hard water ions
Early ones were not biodegradable

29. Think-Pair-Share Explain what you see
Use the words polar and non polar
Hint look at what’s not dissolving
Pg. 97 Figure 1.59

30. Do Now
How do detergents differ from other soaps?

31. Built in Water Softeners
Contains ion exchange resin
Filled with Na+ ions
Hard water ions are attracted to it
Clean resin with NaCl
Usually done at night (hours long process)

32. Figure 1.60

33. Homework
Read pgs
Pg. 102 # 1-11

34. Do Now
1. Chlorine is often used to kill bacteria in town water supplies. List two alternate methods to help disinfect water.
2. What problems are associated with each?

35. Objectives
SWBAT define hard water and list problems associated with it.
SWBAT review their answers to last night’s homework.
SWBAT work on their projects with their partners.

36. Use pages 85-89 to fill in the following chart
Nature’s Cycle
Municipal Treatment
Evaporation
Bacterial Action
Filtration
Other

37. Do Now
What is hard water?

38. Do Now
List 2 ways to soften water.

39. Objectives
1. SWBAT identify the different ions found in hard water and the problems associated with it.
2. SWBAT answer questions on section 1.D.

40. Objectives 1. SWBAT explain how an ion exchange resin works.
2. SWBAT draw pictures of the ion exchange resin on the molecular level.

41. Do Now What things need to be done for your project?
Your Project is DUE: Wed. January 13th

42. Objectives
1. SWBAT work in groups to create a presentation and practice the presentation in front of their peers.
2. SWBAT create 2 questions to ask the other groups

43. Materials for you to Use
Stop Watches
Laptops
Notecards
Paper/Pencils/Markers

44. Objectives
1. SWBAT correct incorrect homework answers and explain why.
2. SWBAT answer multiple choice and short answer review questions

45. Test on FRIDAY… Any questions?
Review Sheet