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Presentation on theme: "Miss Nelson SCIENCE ~ CHAPTER 12 ENERGY AND MATERIAL RESOURCES."— Presentation transcript:


2 Recycling Material Resources SECTION 5

3 ANTICIPATORY SET What kind of things does your family throw away? How does your family get rid of its trash?

4 S 6.3.c – Students know the natural origin of the materials used to make common objects STANDARDS

5 What are three methods of handling solid waste? What can people do to help control the solid waste problem? THE BIG IDEA

6  Municipal solid waste – waste produced in homes, businesses, and schools  Incineration – the burning of solid waste  Leachate – polluted liquid produced by water passing through buried wastes in a landfill  Sanitary landfill – a landfill that holds nonhazardous waste such as municipal solid waste and construction debris KEY TERMS

7  Recycling – the process of reclaiming and reusing raw materials  Biodegradable – capable of being broken down by bacteria and other decomposers  Composting – the process of helping biodegradable wastes to decompose naturally KEY TERMS

8 Read Recycling Material Resources on page 506 of your textbook RECYCLING MATERIAL RESOURCES

9  In our daily activities, we generate many types of waste  Used paper  Empty packages  Food scraps  These materials are produced in homes, businesses, schools, and other places in the community  Called municipal solid waste  Other sources of solid waste include  Construction debris  Certain agricultural/industrial wastes THE PROBLEM OF WASTE DISPOSAL

10 Three methods of handling solid waste:  Burning  Burying  Recycling Each has its advantages and disadvantages THE PROBLEM OF WASTE DISPOSAL

11  The burning of solid waste  Advantages  Burning facilities do not take up much space  Do not pose a risk of polluting ground water  The heat produced can be used to generate electricity  Disadvantages  Even the best incinerators release some pollution into the air  Reduce the volume of waste by 90% - some still remains  This remaining waste needs to go somewhere  Expensive to build INCINERATION

12  Until fairly recently, people usually disposed of waste in open holes in the ground  Rainwater falling on a dump dissolved chemicals from the wastes, forming a polluted liquid called leachate  Could run off into streams and lakes, or trickle into groundwater  In 1976 open dumps were banned  Now much solid waste is buried in landfills that are constructed to hold waste more safely  However, even well-designed landfills still pose a risk of polluting groundwater LANDFILLS

13 Read The Problem of Waste Disposal on pages 507- 508 of your textbook THE PROBLEM OF WASTE DISPOSAL

14  The process of reclaiming raw materials and reusing them to create new products  Any material that can be broken down and recycled by bacteria and other decomposers is biodegradable  Unfortunately, many of the products people use today are NOT biodegradable  A wide range of materials can be recycled RECYCLING

15 Most recycling focuses on four major categories of products:  Metal  Plastic  Glass  Paper RECYCLING

16  Metals such as iron and aluminum can be recycled  With recycling, no ore needs to be mined, transported, or processed  Recycling metals helps conserve these nonrenewable resources METALS

17  When oil is refined to make gasoline and other petroleum products, solid materials called resins are left over  Resins can be heated, stretched, and molded into plastic products  When these products are recycled, they take on very different forms!  Fleece jackets  Carpeting  Floor tiles  Trash cans PLASTIC

18  Glass is made from sand, soda ash, and limestone mixed together and heated  Glass is one of the easiest products to recycle because glass pieces can be melted down over and over to make new glass containers  Recycling glass is less expensive than making glass from raw materials GLASS

19  It takes about 17 trees to make one metric ton of paper  Most paper products can only be recycled a few times  Each time paper is recycled, the new paper is rougher, weaker, and darker PAPER

20  Besides conserving resources, recycling also saves energy  Making aluminum products from recycled aluminum rather than from raw materials uses about 90 percent less energy overall  For certain materials, recycling is usually worthwhile IS RECYCLING WORTHWHILE?

21  Recycling is not a complete answer to the solid waste problem  For some cities, recycling is not cost-effective  Scientists have not found good ways to recycle some materials  The value of recycling must be judged on a case by case basis IS RECYCLING WORTHWHILE?

22 Read Recycling on pages 509-510 of your textbook RECYCLING

23  Reduce  Reuse  Recycle WHAT PEOPLE CAN DO

24  Create less waste by reducing your use of non-recyclable materials  You can also make an effort to buy products made from recycled materials  Start a compost pile WHAT PEOPLE CAN DO

25 Name three ways of dealing with solid waste. CHECK FOR UNDERSTANDING

26 Name three ways of dealing with solid waste. Three ways of dealing with solid waste are burning, burying, and recycling. CHECK FOR UNDERSTANDING

27 Describe an advantage and disadvantage of each method. GUIDED PRACTICE

28 Describe an advantage and disadvantage of each method. Incineration can be used to generate electricity, but can pollute air. Burying waste in a sanitary landfill can possibly pollute groundwater, but the land later can be used for other things. Recycling conserves nonrenewable resources, but it is not always cost effective. GUIDED PRACTICE

29 Complete Energy 12-5 Independent Practice INDEPENDENT PRACTICE


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