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Waste

Waste. Chapter 19. The Generation of Waste. More than 10 billion tons of solid waste generated each year in the U.S. Solid waste - any discarded solid material The amount of solid waste each American produces each year has more than doubled since the 1960s. Space and Waste.

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Waste

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  1. Waste Chapter 19

  2. The Generation of Waste • More than 10 billion tons of solid waste generated each year in the U.S. • Solid waste - any discarded solid material • The amount of solid waste each American produces each year has more than doubled since the 1960s

  3. Space and Waste • Many towns are running out of space to dispose of the solid waste • Difficult to find places that will allow a landfill

  4. Space and Waste • Example: barge 1987 from Islip, NY http://www.nytimes.com/video/booming/100000002206073/voyage-of-the-mobro-4000.html

  5. Population and Waste • Thousands of years ago waste consisted mostly of animal and vegetable matter. • Decomposed rapidly • Large amounts of space and a smaller human population made disposing the waste easier • The human population today is larger, the amount of waste produced is more and the amount of land available to dispose of waste is less.

  6. Types of Solid Waste • Municipal Waste: what we throw out on a day-to-day basis. • Manufacturing Waste: computers, audio equipment, printers • Mining Waste: waste rock, minerals, topsoil

  7. Not All Wastes Are Equal • Biodegradable - A material that can be broken down by biological processes • Plant and animal matter decay and absorbed back into the environment. • Nonbiodegradable - A material that cannot be broken down by biological processes. • Synthetic materials do not decay • Ex. Plastic and nylon

  8. Biodegradable Nonbiodegradable

  9. Plastic Problems • Plastics are made from petroleum or natural gas. • Plastics are synthetic • There are no microorganisms to break down the plastic. • Plastics will last until microorganisms evolve a way to break down the plastics. • This could take hundreds of thousands of year or longer

  10. Municipal Solid Waste • Municipal solid waste - waste produced by households and businesses • Amount of MSW grows faster than mining or agricultural waste • 2% of the total solid waste per year in the U.S. • 210 million metric tons each year • Enough waste to fill a convoy of garbage trucks that would stretch around the earth six times!

  11. Solid Waste from Manufacturing, Mining, and Agriculture • Manufacturing - 56% of solid waste • Scrap metal, plastics, paper, sludge, and ash. • Consumers indirectly create this waste by purchasing manufactured products. • Mining • Rock and minerals left exposed, dumped in oceans or used to refill mines • Agriculture • Crop wastes and manure • Biodegradable and reusable (pesticides and fertilizers can make it hard to dispose of)

  12. Solid Waste Management • Most municipal waste in US is sent to a landfill. • Some waste is incinerated. • Some waste is recycled (28% presently vs. 6.6% in 1970.)

  13. Landfills • More than 50% of the solid waste ends up in landfills • Landfill - permanent waste disposal facility where wastes are put in the ground and covered each day with a layer of soil, plastic or both

  14. Landfills • The function of a landfill is to keep the waste contained and prevent it from causing problems in the environment. • The waste must not come in contact with soil or water that surrounds the landfill

  15. Problems with Landfills • Leachate - liquid that has passed through compacted solid waste in a landfill. • Leachate forms when water seeps down through the landfill. • Leachate may contain dissolved chemicals from the waste. • Ex. Paints, pesticides, cleansers, toxins • Landfills store and monitor leachate. • Leachate is often treated as waste water

  16. Problems with Landfills • Methane is produced by anaerobic bacteria slowly decomposing the waste. • Methane is a highly flammable gas. • Methane is usually pumped out of landfills and used as fuel

  17. Problems with Landfills • The solid waste decomposes very slowly. • The solid waste in the landfill is not exposed to the environment. • The waste is compressed so that there is no oxygen. • Anaerobic bacteria decompose the waste very slowly. • Example - Newspapers discarded in the 1930s are well preserved and readable.

  18. Safeguarding Landfills • The Resource Conservation and Recovery Act - 1976 • Reduced pollution problems of new landfills • Landfills must be lined with a clay and a plastic liner • Landfills must have a system to collect leachate. • Vent pipes must carry methane out of the landfill

  19. Building More Landfills • Lack of space to build landfills. • The solid waste in current landfills is not decomposing. • Landfills are filling up faster than new ones can be built.

  20. Building More Landfills • The EPA estimates that the active landfills in 20 states will be filled to capacity within 10 years.

  21. Incinerators • Incinerators reduce solid waste by burning it. • Reduces the weight of solid waste by 75% • Creates air pollution by burning waste that should not be burned. • The incinerated material can become more toxic after it is burned

  22. https://www.youtube.com/watch?v=Y6LzB6rMDtA – NYC garbage • https://www.youtube.com/watch?v=TOpYa5OKGgY – day in the life of your garbage – cal • https://www.youtube.com/watch?v=mA608GJ-EzM – landfill field trip

  23. Reducing Solid Waste • Source Reduction - any change in design, manufacture, purchase, or use of materials or products to reduce their amount of toxicity before they become municipal solid waste.

  24. Reducing Solid Waste • What you purchase influences manufactures by creating a demand for a product • Buying less • Buy products that have less packaging • Products that last longer • Use a product as long as possible. • Buy products that are environmentally friendly

  25. Recycling • Recycling - process of reusing materials or recovering valuable materials from waste or scrap. • Saves energy, water and other resources

  26. Recycling Saves Energy • 95 percent less energy is needed to produce aluminum from recycled aluminum than from ore • 5 percent less energy is needed to make steel from scrap than from ore • 70 percent less energy is needed to make paper from recycled paper than from trees.

  27. Recycling: Steps • Discarded materials are collected and sorted by type - paper, plastic, glass, aluminum • The sorted materials are then taken to the appropriate recycling facility based on the type of material. • The materials are then cleaned and processed. • The recycled materials are used by manufactures to make new products which are sold to consumers.

  28. Composting • Yard waste makes up more than 15% of municipal solid waste. • This waste does not need to go to a landfill. • Yard waste is biodegradable and becomes compost • Compost - a dark brown organic material rich in nutrients from decayed plant and animal matter. • Compost is often used in fields and gardens to enrich the nutrients in the soil. • Composting more can significantly reduce the amount of solid waste in a landfill

  29. Changing the Materials We Use • single-serving drink boxes are made of a combination of foil, cardboard, and plastic. • The drink boxes are hard to recycle because there is no easy way to separate the three components.

  30. More products could be recycled if they were made of… • Recyclable glass • Cardboard • Aluminum

  31. Changing the Materials We Use • Photodegradable plastics - plastics that when left in the sun for many weeks becomes brittle and breaks into pieces. • Most plastics are not exposed to the sun long enough and become buried or submerged in water. • The small pieces end up in the ocean and lakes and are consumed by filter feeding animals • If the plastic does biodegrade the toxins used to make the plastics are released into the environment

  32. Changing the Material We Use • Green plastic - cellulose from plants is blended with plastics. • 20-50% less fossil fuel is used. • The cellulose breaks down and the remaining plastic breaks into small pieces. • The small pieces end up in the ocean and lakes and are consumed by filter feeding animals

  33. Degradable Plastics: Photodegradable Plastic • when it is left in the sun for many weeks, it becomes weak and brittle and eventually breaks into pieces.

  34. Degradable Plastics: Green Plastic • made by blending the sugars in plants with a special chemical agent to make plastic • labeled as green because they are made from living things • considered to be more environmentally friendly than other plastics. • Production requires 20 to 50 percent less fossil fuel than the production of regular plastics does. • When this plastic is buried, the bacteria in the soil eat the sugars and leave the plastic weakened and full of microscopic holes. • The chemical agent gradually causes the long plastic molecules to break into shorter molecules. These two effects combine to cause the plastic to eventually fall apart into small pieces.

  35. Problems with Degradable Plastics

  36. Photodegradable plastic Biodegradable plastic

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