Why is it managed?
Silent Spring Love Canal Times Beach and
Seveso, Italy Bhopal, India
Methyl isocyanate Toxins Dioxin Pesticides
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Household and Other Special Haz Wastes
RCRA Hazard
Ignitable
Corrosive
Toxic
Reactive
None
Material
Bleach
Drain cleaner
Lighter fluid
Antifreeze
Aspirin
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In-Class Activity
An industrial plant produces approximately 1000 kg/month of waste pentachlorophenol (C6Cl5OH). The plant decides to install an incinerator to dispose of the waste. Assume complete combustion. Note that this reaction requires water.
• How much oxygen is theoretically required to combust the material?
• How much acid is theoretically produced?
• What theoretical quantity of sodium hydroxide (NaOH) is required to neutralize the acid?
• In operation, why would you expect the quantities of air, acid, and caustic to be different from the theoretical amounts?
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Which activities are the riskiest?
Action 4 tbs peanut butter daily Alcohol, cancer All cancers Background radiation Car accident, death Flesh-eating bacteria Home accident, death Homicide Radon in home, death Ski, death Smoking 1 pack/d, cancer Struck by lightening
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Risk Assessment
Hazard Identification
Exposure Assessment
Dose-Response Assessment
Risk Characterization
9
Soil water (root zone)
Unsaturated or vadose zone
Capillary fringe
Saturated zone (Groundwater)
Confining layer
Where is the contamination?
11
In-Class Activity
Explain why the proposed process would be inappropriate for a site with the given contaminant. Offer a plausible alternative.
Volatile soluble organic – excavation & landfillingSoil in vadose zone contaminated with metals – pump & treatSoil in unsaturated zone contaminated with radioactive waste – in-situ bioremediation
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In-Class Activity
Lake Jasmine is a 20-acre lake with an average depth of 30 ft. Yesterday afternoon four 55-gallon drums of Fuel Oil A and six 55-gallon drums of Solvent C fell off a truck during an accident, rolled into Lake Jasmine, and burst open on the rocky shore. The entire contents of all the drums spilled into the lake. Should local public health officials take measures to keep vacationers near Lake Jasmine out of the water? The allowable quantity in recreational waters of Fuel Oil A is 2.2 ppm, and the allowable quantity of Solvent C is 1.3 ppm.
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Choose the best answer.
A. Radiation is scary. Radioactivity is even scarier.
B. Radiation is a method of surveying in which points are located by knowledge of their distances and directions from a central point. Radioactivity is the intensity of a radioactive source.
C. Radiation is emitted energy without the absorption of any energy. Radioactivity is a characteristic natural, spontaneous process in which unstable atoms emit mass or energy.
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Uses of Radiation
Historical/Discontinued
X-rays: Hair removal, Shoe sizing
226Ra: Hair tonic, Skin cream, Clock dials, Toothpaste, Chocolate bars
210Po: Spark plugs 232Th: Toothpaste, Dentures Uranium: Pigments,
Photographic toner, Adhesive tape dispenser
Current
235U, 239Pu: Reactor fuel 241Am: Smoke detectors 60Co, x-rays: Food sterilization x-rays, -rays: Medical instrument
sterilization 60Co, 131I, etc.: Radiation treatment Neutrons: Bomb detection, Illegal
drug shipment detection
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There are lots of units Curie (Ci): decay rate Becquerel (Bq): decay rate, 1 per second Roentgen (R): rate of ionizations produced Rad (radiation absorbed dose): energy absorbed
from radiation Rem (roentgen equivalent man): energy
absorbed by tissue Gray (Gy): absorption of 1 J of energy per kg of
absorbing material Sievert (Sv)): dose equivalent to tissue damage
from 1 Gy of gamma radiation or X-ray = 100 rem29
Annual Radiation DoseLocation or Situation Dose
(mrem) Ramsari, Iran 48,000 Guarapari, Brazil 17,500 Radiation worker 5,000 St. Peter’s Square 800 NYC Grand Central Station 525 Background 300 – 400 Decommissioning 15
Internal
11%
Cosmic8%
Terrestial8%
Consumer Products
3%Nuclear Medicine
4%
Other<1%
Radon54%
Medical X-rays11%
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Effects of Level of Ionizing Radiation
Dose (rem) Effects0 - 25 May reduce white
blood cell count25 - 100 Nausea, fatigue,
blood changes100 - 200 Nausea, fatigue, low
white blood cellcount, deathpossible
200 - 400 LD50, bone marrow &spleen damage
> 600 Fatal
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Half Life
Time required for half of original material to decay
Characteristic of an isotope
A = Aoe-t
t1/2 = ln 2
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