Chapter 26 Solid Waste Disposal

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Chapter 26Solid Waste Disposal

• Objectives
• Describe the kinds and sources of solid waste
• Explain hazards in solid waste materials and
  disposal
• Describe ways of disposing of solid wastes
• Explain recycling
• Describe composting

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Terms
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Materials in Solid Waste

• Solid waste is garbage, refuse, sludge, and other
  discarded material
• Solid waste are often placed in four groups
• Garbage usually means the materials discarded
  from a kitchen
• Rubbish, or trash, is paper, plastic, bottles,
  metals, and yard and garden wastes
• Ash is the residue from the combustion process
• Bulky solid waste includes large items used in
  the home, a business, or factory that are being
  discarded

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Solid Wastes
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Sources of Solid Waste
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1. Domestic Solid Waste

• Domestic solid waste is the solid waste from
  homes and apartments
• It is the solid waste from the daily living
  activities of people and is sometimes known as
  residential waste
• It does not include wastes from institutions,
  such as schools and hospitals

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2. Commercial Solid Waste

• Commercial solid waste is the refuse from
  offices, retail stores, schools, and restaurants
• Some solid wastes are garbage, other solid waste
  are rubbish and bulky items

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3. Medical Wastes

• Medical wastes include those from human health
  care and veterinary medicine
• Health care facilities have medical wastes
  including syringes, hypodermic needles, and human
  fluids and tissues

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4. Municipal Solid Waste

• Municipal solid waste includes all solid
  materials from the activities of a town or city
• It does not include wastes from homes and
  businesses, though their disposal may be combined
  with the municipal wastes
• The municipal wastes include materials from
  cleaning streets and parks, dead animals,
  abandoned cars and furniture, and wastewater
  treatment residues
• Some of the material can be disposed of with
  domestic solid wastes

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5. Industrial Solid Waste

• Industrial solid waste is from manufacturing
• Some of the waste is much like commercial waste
  resulting from the offices and activities of the
  people who work in the facility
• The solid waste from manufacturing varies with
  the nature of the products that are made

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6. Construction and Demolition Solid Waste

• Construction solid waste include scraps of
  lumber, broken brick, pieces of electrical wire,
  roofing material scraps, and unused concrete
• Demolition solid waste are the material remaining
  when a building or other structure is destroyed

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7. Agricultural Solid Waste

• Agricultural solid wastes are the materials
  created in raising animals and growing crops
• The kind of animal waste varies with the animal
  being raised and how it is produced
• Crop residues include stalks, hulls, and leaves

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Hazards in Solid Waste

• Health
• Pests
• Safety
• Pollution

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Leachate

• Leachate is the liquid that has passed through
  solid waste
• Leachate is water that contains suspended or
  dissolved materials from solid waste

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Typical Landfill Leachate Content and
Characteristics
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Steps in Solid Waste Management
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Methods of Solid Waste Disposal
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1. Incineration
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2. Landfill

• A landfill is an area of excavated land where
  wastes are placed for permanent disposal
• A sanitary landfill is used to dispose of
  non-hazardous wastes
• A chemical landfill is used to dispose of
  hazardous wastes

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How a modern sanitary landfill is operated
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Design of a sanitary landfill
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3. Recycling

• Recycling is reusing a product or the materials
  used to make the product

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Kinds of Recycling

• Remanufacturing is making a product that has been
  previously used into another product, example
  include remanufacturing glass bottles, plastic
  jugs, and newspaper
• Reusing is using a product again without
  remanufacturing

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Materials Recycled

• Aluminum
• Paper
• Plastics
• Iron and other metals
• Glass

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Center for depositing items for recycling
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Recycling Processes

• Recycling can begin at the source of the solid
  waste
• Curbside recycling is the collection of sorted
  items at the curb
• Drop-off recycling centers are places where
  people carry the items to be recycled to a
  central, but usually convenient, location
• Buyback recycling center pay people for the
  products they bring for recycling

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Composting

• Composting is the controlled biological
  decomposition to degrade organic matter
• Compost is used for fertilizer, topsoil, landfill
  cover, and in other ways
• The metabolic activity of the microorganisms can
  easily cause the temperature in the composting
  materials to rise to above 60 degree C
• The microorganisms also like a fairly high
  moisture content or about 40 to 50 percent water,
• The material should contain 15 to 18 percent
  oxygen and have a pH of 5.0 to 8.5

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Small home compost bin
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Arrangement of alternating layers of materials in
a compost bin
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General design of a small composting bin for the
home
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Tests

• What are the common materials found in solid
  waste?
• What are the major sources of solid waste?
  Distinguish between each.
• What hazards are posed by solid wastes?
• What is leachate? How can it cause a problem in
  the environment?
• What steps are important in the process of solid
  waste management?
• What methods are used to dispose of solid waste?
• What is recycling? What kinds of materials are
  recycled?
• What is composting?