Water Resources

1
Water Resources Water Pollution
2
Distribution of Water on Earth
3
Water Content of Organisms and Food
4
Major Constituents of Seawater
5
Major Ions in Freshwater and Seawater
6
Hydrologic Cycle
7
Hydrogen Bonding
8
Comparison of Boiling Point
9
Heat Capacity

• Heat Capacity is the quantity of heat required to
  raise the temperature of one gram of a substance
  by 1?C.
• Water has the highest heat capacity of any common
  liquid.
• Because of waters high heat capacity, the oceans
  absorb energy from the sun and moderate our
  climate.

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Heat of Fusion Heat of Vaporization
11
Density of Water

• Density Mass/Volume
• The density of most liquids increases with
  decreasing temperatures.
• Water reaches its maximum density at 4?C.
• Solid water (ice) is less dense than the liquid.

12
Aquatic Life and Ice

• When air temperature falls below freezing, water
  surface freezes.
• If ice were more dense than liquid water, it
  would fall to the bottom and freeze bottom up.
• Since ice is less dense than water, the ice on
  the surface forms a solid layer.
• The sold layer of ice acts as an insulator that
  keeps the water in the lake from freezing.

13
Ogallala Aquifer
14
Areas of Groundwater Overdraft
15
Daily Water Use (per capita)
16
Water Conservation in the Home
17
Reverse Osmosis
18
Point and Nonpoint Sources of Water Pollution
19
The Solubility of Oxygen in Water
20
The Reduction in Dissolved Oxygen by Pollutants
21
Products of Aerobic and Anaerobic Decomposition
22
Bioaccumulation
23
Maximum Permissible Levels for Metals in Drinking
Water
24
Structures of Chlorinated Pollutants
25
Sewage Treatment
Primary Treatment

• Screen used to remove large pieces of debris
• Grit chamber
• Sedimentation tank- produces sludge
• Calcium hydroxide and aluminum sulfate are added
  to speed up the sedimentation process
• 3 Ca(OH)2 Al2(SO4)3 ? 2 Al(OH)3 3CaSO4

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Sewage Treatment
Secondary Treatment

• Aerobic bacteria which are called activated
  sludge is added
• Air is bubbled into mixture
• The organisms break down organic material into
  carbon dioxide and water
• Treatment with chlorine before release (if there
  is no tertiary treatment)

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Disinfection with Chlorine

• Chlorine gas reacts with water to form
  hypochlorous acid (HClO) which is a powerful
  oxidizing agent.
• HClO kills disease causing bacteria.
• Chlorine reacts with other organisms in the water
  to produce disinfectant by-products (DBPs) which
  are suspected of causing birth defects,
  miscarriages, and cancer.
• Ozone, O3, is used in the place of chlorine to
  disinfect drinking water in Europe.

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Sewage Treatment
Tertiary Treatment

• Removes DBPs produced in secondary treatment.
• Water is passed through granular charcoal that
  has been activated by heat.
• Excess phosphates are removed by the addition of
  aluminum sulfate and lime (CaO).
• 3PO43- Al3 3Ca2 ? AlPO4 Ca3(PO4)2
• ? Calcium phosphate Ca3(PO4)2 is insoluble in
  water and precipitates.

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Sewage Treatment Plant