Chapter 27 Hazardous Waste Disposal

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Chapter 27Hazardous Waste Disposal

• Objectives
• Explain hazardous wastes
• Classify wastes on the basis of hazard
• Describe ecotoxicology and list three areas
• Explain ways of disposing of hazardous wastes
• Describe procedures with hazardous waste spills
• Describe the symbol system of hazardous material
  and waste

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Terms
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Hazardous Waste

• A hazardous waste is a waste that is potentially
  dangerous to human health or the environment

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Common Hazardous Materials in and Around the Home
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A sign is used to inform people of a hazardous
material at a construction site
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Classification of Hazardous Waste

• Characteristic hazards
• Health hazards
• Physical hazards
• Compressed gas hazards
• Radioactive hazards
• Other hazards

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1. Characteristic Hazards

• Ignitability
• Ignitability is the readiness of a waste to burn
• Ignition temperature is the lowest temperature at
  which burning begins
• Combustion is the rapid combination of oxygen
  with fuel source
• Falmmability is the ease with which a substance
  can be set on fire
• Reactivity is how reactive a waste is in
  responding to an outside force
• Corrosivity refers to the corrosive
  characteristics with tissue, metals, or other
  materials
• Toxicity is the degree to which a waste is
  poisonous

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Labels on a bag of ammonium nitrate fertilizer
warn of its dangers
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Pesticide labels warn of hazards
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2. Health Hazards

• Health hazards are conditions that endanger human
  health
• Chronic
• Acute

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Health Hazards used to Classify Hazardous
Materials
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3. Physical Hazards

• Combustible liquid
• Flammable material
• Explosives
• Oxidizer
• Organic peroxides
• Pyrophoric
• Water reactive

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4. Compresses Gas Hazards

• The compressed materials may be a gas or mixture
  of gases in containers at pressure

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5. Radioactive Hazards

• Radioactive wastes emit radiation
• High-level wastes are typically from nuclear
  energy reactors and other processes that use
  uranium, the waste is stored in an approved
  geologic repository
• Transuranic wastes are from radioactive materials
  other than uranium, such as plutonium and curium
• Low-level radioactive wastes contain
  radioactivity below transuranic materials, these
  wastes are typically produced by hospitals,
  industry, and research institutions

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6. Other Wastes

• Wastes from oil exploration and mining minerals
• Ore may contain radioactive material or heavy
  metals

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Environmental and Ecosystem Toxicology

• Environmental toxicology deals with the effects
  of hazardous materials, including wastes, in the
  environment on living organisms
• Ecotoxicology deals with the effects of toxic
  substances on an ecosystem

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Environmental and Ecosystem Toxicology

• Habitat destruction
• Reproductive failure
• Reproductive toxicology deals with the failure of
  adult organisms to reproduce due to toxic
  substances in the environment
• Development toxicology is the failure of
  offspring to develop properly, abnormal growth
  and disease are signs of development toxicology
• Disease
• Chemical substances that cause cancer in animal
  tissue are classified as carcinogenics

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Disposing of Hazardous Waste
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1. Hazardous Waste Landfills

• Some wastes are encapsulated before being placed
  in landfills
• Encapsulation involves placing in or forming
  wastes into capsules before placing them in
  landfills
• Biological seeding is used to assure the presence
  of bacteria that will biodegrade a waste, this
  involves placing specific bacteria with the waste

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Design of a Hazardous Waste Landfill
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System for Storing Drums of Waste in Concrete
Cubes Deep in the Earth
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2. Minimizing Hazardous Waste

• The amount of hazardous waste can be reduced by
  recycling usable components and using treatment
  processes on other wastes

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Some hazardous wastes can be put in the drums and
the drums compacted
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3. Deep Well Injection

• Deep well injection is pumping liquid hazardous
  waste deep into the earth
• Areas with the earthquakes should not be used

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4. Incineration

• Destruction depends on the material and
  temperature at which it is incinerated, for
  example, temperature above 1,000 degree C destroy
  dioxins
• Incineration is not effective for radioactive or
  chemical wastes in elemental form
• The gases released by incineration must be
  carefully scrubbed to remove pollutants released
  into the atmosphere
• Ash left from incineration is disposed of in a
  landfill

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5. Detoxification

• Detoxification is removing toxin from a material,
  wastes may be converted into other less-hazardous
  materials
• Bioengineered bacteria are being used to secrete
  enzymes that breakdown substances into materials
  that can be absorbed

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A treatment facility for removing heavy metals
from water
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6. Waste Exchange

• A waste created by one source may be a product
  that another source can use
• Waste exchange may be a good idea, but is
  difficult to carry out

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Spills and Accident in Transportation and
Manufacturing

• A spill is uncontrolled discharge of materials,
  most of the time spills are accidental
• The material that is discharged in a spill may be
  hazardous, it is called a hazardous waste spill
• A system of color-coding and numbering has been
  developed to help identify hazardous materisls

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Spill Clean-Up
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Cleaning up a small oil spill from an automobile
accident on a road
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Code (NFPA)

• A color code is used to help explain the kind of
  hazardous material that is being transported (red
  indicates a flammable materials, yellow indicates
  reactivity, blue is for health hazard, and white
  is all other materials) (National Fire Protection
  Standard No. 704)

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Classes of Hazardous Materials (U.S.DOt)
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Identification Numbers of Selected Common
Hazardous Materials
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Placard

• A placard used on a vehicle that transports
  liquefied petroleum (propane) helps identify the
  material
• The red color indicates that the material is
  flammable, the number at the bottom is the class
  of materials, and the four-digit number is the
  identification number
• Here, 2 means the material is a gas and 1075
  specifically identifies the material as propane

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This shows examples of placards for various
hazardous materials
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United Nation Classification System
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Tests

• What is a hazardous waste? How is it
  distinguished from other waste?
• Explain four ways wastes are classified on the
  basis of characteristics hazard
• What are the major health hazards?
• What are physical hazards?
• What are radioactive wastes?
• What is ecotoxicology?
• What are the three major areas of ecotoxicology?
• What methods are used to dispose of hazardous
  waste?
• What is spill?