Standards
• W-5: SWBAT describe the process of wastewater treatment
• W-6: SWBAT list and describe the major types of water pollution
Goal of Wastewater Treatment
• Water is filtered and treated to make the water clean enough to return to a river or lake
What’s in the Wastewater?
• Most of the wastewater from homes contain biodegradable material that can be broken down by living organisms
• Water from the kitchen and toilet contain plant and animal wasters, paper, and soaps all of which are biodegradable
Biodegradable or Not?
• Banana Peel
• Soda Can
• Slaughterhouse waste
• Manure
• Glass
• A polyester shirt
The Womp Womp Factor
• Wastewater treatment plants may not remove all the harmful substances in water
• Ex: Household water that contains toxic substances
Sewage Sludge• A byproduct of wastewater
treatment
• The solid material that remains after treatment
$$$• Sludge that contains a high
concentration of toxic chemicals must be disposed of as hazardous waste
• The sludge is often incinerated, and then the ash is buried in a secure landfill
Sustainable Sludge• If the toxicity of the sludge can be
reduced to safe levels, sludge can be:
• 1) Turned into fertilizer
• 2) Combined with clay to make bricks for buildings
Wastewater Treatment Process
• 1) Filtration
• 2) 1st Settling Tank
• 3) Aeration Tank
• 4) 2nd Settling Tank
• 5) Chlorination
Fats, Oils, and Grease (F.O.G’s)
• Builds up in the sewer system and can cause back ups
• Do’s:
• Recycle used cooking oil
• Put food scraps in trash
• Don’t:
• Pour F.O.G.s down the drain
• Use the toilet as a trash can
• Use rags or cloths towels to clean grease
Eutrophication• def: A natural process where a
body of water receives excess nutrients, which causes a loss of oxygen.
• Some nutrients are GOOD, but too many may cause a body of water to become eutrophic
Causes of Eutrophication
• Fertilizers from farms, lawns, and gardens
• Phosphates in some detergents
Whiteboards
• On your whiteboards, write down the definition of thermal pollution and provide some major causes of such.
#3: Thermal Pollution• def: the degradation of water
quality by changing the temperature of a natural body of water
Sources of Thermal Pollution
• Power plants and other industries use water in their cooling systems and then discharge the warm water into a lake or river
• CFU
It’s getting hot in herre...
• As the water temperature rises, the amount of dissolved oxygen decreases
#4: Groundwater Pollution
• Pollutants usually enter groundwater when polluted surface water percolates down from the surface.
Leaking Underground Storage Tanks(LUST)
• Major source of groundwater pollution
• Estimated 1 million+ in the US
• Gas stations
• Storage tanks develop leaks as they age, allowing pollutants to enter the ground
Problems with LUST
• The location of an aging UST is not always known, so tanks cannot be replaced or repaired until they have leaked enough pollutants.
Whiteboards-PPM• Water contamination is often
measured in parts per million (ppm).
• If the concentration of a pollutant is 5 ppm, there are 5 parts of the pollutant in 1 million parts of water.
• Q: If the concentration of gasoline is 3 ppm in 650,000 L of water, how many liters of gasoline are there in the water?
Clean-up Time
• Groundwater pollution is one of the most challenging environmental problem the world faces.
• The process for some aquifers to recycle water and purge contaminants can take 100s or 1000s of years
Sticky Icky Icky
• Pollution can cling to the materials that make up an aquifer.
• Putting clean water in a dirty aquifer is useless!
Oil Spills• Each year, approximately 37
million gallons of oil from tanker accidents are spilled into the oceans
Caution: Slippery when...Oily?
• Oil spills only account for 5% of oil pollution in the oceans.
• Most of the oil that enters the oceans come from cities and towns.
• 200-300 million gallons/yr