1. WATER TREATMENT

3. Point Source of Polluted Water in Gargas, France

5. Is Bottled Water the Answer?
U.S.: some of the cleanest drinking water
Bottled water
Some from tap water
40% bacterial contamination
Fuel cost to manufacture the plastic bottles
Recycling of the plastic
Growing back-to-the-tap movement

6. Trash Truck Disposing of Garbage into a River in Peru

7. Natural Capital Degradation: Highly Polluted River in China

8. Girl Sits on the Edge of a Road beside a Stream Loaded with Raw Sewage in Iraq

9. Sewage Treatment Reduces Water Pollution (1)
STRATEGY IS TO REDUCE POINT SOURCE POLLUTION
Septic tank system
Wastewater or sewage treatment plants

11. SETTLING TANK- where grease and oil rise to the top and sludge settles
SETTLING TANK- where grease and oil rise to the top and sludge settles. Solids are decomposed by bacteria. This is why, in theory, you should not use chlorinated cleaning products.

12. DRAIN FIELD- liquid waste drain from pipes and percolate downward filtering and allowing bacteria to biodegrade materials

14. Solutions: Septic Tank System

15. Process of wastewater treatment
Primary sewage treatment
Physical process-uses large screens and a grit tank to remove large objects and grease and allow organic solids to settle out in the form of sludge.

16. Top view of Forest City Wastewater treatment plant

17. 1. Headworks Building This houses a mechanical bar screen and grit/grease removal system which removes the larger solids and readies the flow for entry into the First-Stage Aeration Basins
2. First-Stage Aeration Basins These two basins provide an optimum oxygen supply for decomposition of the sewage by bacteria. The flow is regularly checked for nutrients, pH, solids, pathogens, metals and organic chemicals. The flow then enters the large Second-Stage Aeration Basin.
3. Second-Stage Aeration Basin Here further oxygenation and decomposition occur. A complex group of micro-organisms break down (feed on) on the suspended or dissolved organic impurities remaining in the water. No chemicals are used throughout this decomposition process, only the natural action of many bacterial species.
4. Clarifiers From the big basin flow gravitates to two clarifiers, the round settling tanks. Remaining solids settle, and most are returned back to the aeration basins at a rate of 1.3 MGD. The clear top layer in the clarifiers is then chlorinated to destroy pathogens, then de-chlorinated with sulfur dioxide prior to release to Second Broad River. This effluent meets or exceeds all EPA requirements for biological oxygen demand rates.

18. Secondary sewage treatment-employs aerobic bacteria to degrade organic waste. Here further oxygenation and decomposition occur. A complex group of micro-organisms break down (feed on) on the suspended or dissolved organic impurities remaining in the water. No chemicals are used throughout this decomposition process, only the natural action of many bacterial species.
Aeration- used to introduce additional oxygen

19. Aeration of sewage to encourage the aerobic bacteria for decomposition

20. Ignaz Semmelweis

23. Tertiary or advance sewage treatment
The clear top layer in the clarifiers is then chlorinated to destroy pathogens,
Bleaching, chlorination kills microorganisms such as chlolera. then de-chlorinated with sulfur dioxide prior to release to Second Broad River
The use of filters to remove phosphates and nitrates

24. Sewage sludge or biosolids

25. Solutions: Primary and Secondary Sewage Treatment