Water resources and pollutions

Anmerkungen:

• subsidence-sinking land DO-Dissolved oxygen is an important parameter to measure when assessing water quality.  BOD-Biochemical oxygen demand (BOD) is the amount of dissolved oxygen needed by aerobic biological organisms

1. subsidence

   Anmerkungen:

   • sinking land

Anmerkungen:

• Freshwater availability – 0.024% – Ground water – Lakes – Rivers – Streams

1. WHO : waterborne disease
2. dry climate
3. more consumer
4. Solution
   1. desalination
      1. RO , distillation
   2. conservation
   3. transporting
   4. irrigation
      1. most efficientive for water usage
   5. reseroire
   6. withdraw groundwater
   7. Treatment
      1. Sewage
         1. septic tank - cesspool
            1. rural suburban
         2. wastewater plant
            1. urban
      2. PBC
         1. Primary
            1. physical process
         2. Secondary
            1. biological process
         3. Chlorination
            1. blenching and disinfection
5. Problem
   1. pollution
      1. point
      2. oxygen sag
      3. non-point
         1. run-off chemical
      4. ocean

         Anmerkungen:

         • high accumulate on nutrien
      5. Lake

         Anmerkungen:

         • stratification problem
      6. Stream

         Anmerkungen:

         • found in developing country
      7. underground water

         Anmerkungen:

         • most concern for purification
      8. mostly agriculture waste
   2. waste and loss water
   3. over-demanding

Anmerkungen:

• • Holds water molecules together – hydrogen bonding • Liquid over a wide temperature range • Changes temperature slowly • Requires large amounts of energy to evaporate • Dissolves a variety of compounds • Filters out UV light from the sun • Adheres to a solid surface – allows capillary action in plants • Expands as it freezes