water purification and treatment
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Water Purification and Treatment. Natural Water Purification. 1. Evaporation 2. Bacterial Action 3. Filtration. Purifying Water through the H ydrologic Cycle. Purifying Water through the Hydrologic Cycle. - PowerPoint PPT PresentationTRANSCRIPT
Water Purification and Treatment
Natural Water Purification
• 1. Evaporation
• 2. Bacterial Action
• 3. Filtration
Purifying Water through the Hydrologic Cycle
Purifying Water through the Hydrologic Cycle
• 1. The sun provides energy for water to evaporate this resembles the process of distillation
• Evaporation leaves behind minerals, heavy metals, and other dissolved substances.
Purifying Water through the Hydrologic Cycle
• Water vapor condenses and falls as precipitation raindrops and snowflakes are nature’s purest form of water containing only dissolved atmospheric gases
• However, human activities release a number of gases into the air making today’s rain less pure than it used to be
Purifying Water through the Hydrologic Cycle
• 2. Bacterial Action• When raindrops strike the soil,
they collect impurities• But, as the water seeps through
the ground the bacteria in the soil feed on those impurities and repurify the water
Purifying Water through the Hydrologic Cycle
• 3. Filtration
• As water seeps further into the ground, it passes through gravel, sand, and rock
• This allows bacteria and suspended matter to be filtered out
Municipal Water Purification
• Major Steps• 1. Screening• 2. Prechlorination• 3. Flocculation• 4. Settling• 5. Sand Filtration• 6. Post chlorination• 7. Optional Further TreatmentRead article on pages 88-89 and define these terms
Chlorination of Water
• Read article on page 90 and outline the 3 methods of chlorination.
• What is a potential problem with water chlorination?
Chlorination and THM’s
• Ways to eliminate THM health risk• 1. Pass water through activated
charcoal filter.– Can get rid of THM’s but expensive to
install and operate.• 2. Use ozone or UV light instead of
chlorination– Won’t protect the water from
contaminants once it has left treatment plant
Hard Water
• Hard Water is water containing an excess of dissolved calcium (Ca2+) ions, magnesium (Mg2+) ions, or iron (III) (Fe3+) ions
• As water flows through limestone, chalk, and other rocks, these ions seep into the water
US Groundwater HardnessIs Your Water Hard or Soft?
How do we soften water???
• Water Softening Lab• 3 ways• 1. Sand Filtration• 2. Treatment With Calgon– http://www.youtube.com/watch?v=ZjNRXfRXnoc
• 3. Treatment with an Ion-Exchange Resin– http://www.youtube.com/watch?v=vCg-I5U9X3w