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"According to the World Wildlife Fund's 2006 Living
Planet Report, we are now turning resources into waste
25% faster than the Earth can turn waste back into
resources“ –John Green
Methods of Waste Disposal
 Landfill Sites
 Incineration
 Recycling
 Burial of Radioactive Waste
LANDFILLS!!!!
A Little About Landfills
 Waste is increasing rapidly, so sequentially landfills
compactly is decreasing.
 Landfills take up land where people, animals and
plants could be growing
 They are the most common form of waste disposal
The Pros
 Waste is out of sight out of mind
 People believe once the garbage has left there home or
office it doesn’t effect them….. WRONG!!!
 Its easy
 That’s It, there are many better alternatives to landfills
including recycling and incineration
The Cons
 Ugly, Stinky, Space consuming, Loads of garbage
 Transportation costs to landfills are high and tend to
be far away from cities. For example Toronto
outsourced their garbage all the way to Michigan.
 Underground water and soil pollution can
permanently scar the surrounding land as well as the
organisms living there
 Anaerobic decomposition of organic wastes, such as
most foods, plants, and some other garbage can
releases the green house gas methane (CH4) as well as
ammonia (NH3), Hydrogen Sulfide and others
Medical waste and biological
contaminates
 Medical Waste also tends to be thrown in landfills,
although not much of this waste can be recycled, some
materials can be made from recycled goods which
ultimately cuts down on garbage, this includes things like
pipette tips, as well as biological storage bags or boxes.
Found on http://www.ehs.uci.edu/programs/biosafety/medwasteguide.pdf
 Other medical waste includes
 CHEMO waste
 Sharps
 Pharmaceutical
 Chemical waste
INCINERATION!!!
What’s the deal with
incineration?!?!
 Incineration is the burning and
melting of garbage in order to
produce energy and slag
 This resulting slag can either be
used in construction such as
building roads and buildings or be
safely discarded in a landfill
 Incineration also requires energy to
transport waste similar to a landfill,
however in the burning process
some energy can be recovered
The good, the bad, and the ugly
The Pros
The Cons
 Creates Energy
 Expensive, and still uses more
 Doesn’t scar the land like a
energy that eat creates
 The burning of plastics
release dioxins into the
environment
 Slag doesn’t serve many
purposes
landfill
 Can kill disease causing
microorganisms
 Uses less space, and is not as
unattractive as a landfill
RECYCLING!!!
Recycling
 Recycling is presently the best way to get rid of waste.
Not only does it reduce green house gasses, conserve
energy, and have lower costs, but your neighbors will
thank you for it!
 The recycling process is divided into four parts
 Glass
 Metals
 Plastics
 Paper Products
Glass-The process
 1st Glass is separated by colors mainly, clear, amber,
and green, many glass containers for food and drinks
fall into these categories. However special composition
glass such as mirrors and light bulbs cannot be
recycled.
 2nd The glass in than crushed, and is now called
“cullet.”
 3rd The glass is exposed to magnets to remove metal
and a vacuum to get rid of paper and plastic.
 4th The glass is finally heated to about 1200˚C where it
is mixed with sand, limestone, or ash to create new
bottles jars and tiles
Glass- The Benefits
 Reduces costs in mining for new glass such as mining
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waste and cost of raw materials
Uses only a third the energy to produce as virgin glass
Uses only half the water virgin glass does
Reduces use of landfills
Cullet can be used in construction
Glass can be recycled over and
over again
Metals- The Process
 The metals must be separated into ferrous metals and
non ferrous metals (I.E. Tin cans separated from
Aluminum cans)
 1st The Metal is cut up than
magnets separate the lighter
aluminum metal by flotation.
 Next the metals are melted
and reused
Metals-The Benefits
 Conserves raw materials
 Dramatically reduces energy costs, water use, and
landfill use, therefore less greenhouse gasses
 Aluminum and steel, the most common recycled
material, can be recycled over and over again!
Non ferrous (left)
Ferrous (right)
Plastics
Plastic-The Process
 Because of the many different types of plastic, such as
polyethene and polystyrene, it is expensive and
difficult to recycle plastics.
 Hence the numbering system which helps to manually
separate similar plastics.
 Low density polyethylene (LDPE), polypropylene (PP),
polystyrene (PS) can not always be recycled however
polyethylene terephthalate (PETE) and high density
polyethylene (HDPE) can.
 Once similar products are combined they are melted
and reused
 PETE- polyethylene terephthalate-
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found in soft drink, water and beer
bottles etc.
HDPE- high density polyethylenefound in bleach, milk jugs, juice
bottles etc.
V-vinyl- found in PVC
LDPE- low density polyethyleneSqueezable bottles, bread, frozen
food, dry cleaning and shopping
bags
PP- polypropylene- found in some
yogurt containers, syrup bottles
and ketchup bottles
PS- polystyrene- found in
Disposable plates and cups, meat
trays, egg cartons and carry-out
containers
Plastics-The Benefits
 Greatly reduces landfill sites and use of incinerators
 Uses less petrochemicals
 Uses less energy and water compared to virgin plastics
 There are many uses for recycled plastics, from plastic
lumber such as Trex to polyester fibers.
Paper
Paper-The Process
 Paper with wax or plastic coatings cannot be recycled
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therefore paper must first be separated
Paper is than chopped and mixed with water as well
chemicals such as Calcium Oxide (CaO) and Calcium
Carbonate (CaCO3)
This process brakes the paper down and creates pulp.
Spinning this pulp than removes heavy objects like
paper clips and staples, the ink is than washed away by
adding more water
Other chemicals are used to remove dyes, inks, and
glues
Paper-The Process cont.
 Often fresh pulp is added, if this not treated to remove
lignin, a glue in wood that holds fibers together, the
paper will turn yellow in sunlight such as with
newspapers
 Hydrogen Peroxide (H2O2) or Chlorine Dioxide
(ClO2) can also be used to bleach the paper
Paper- The Benefits
 Only needs half the energy and water that virgin paper
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needs
Reduces trees that have to be cut down, preserving
natural forests and saving animal habitats
By saving forests use also reduce greenhouse gasses as
CO2 is consumed by plants
Extends life of landfill sites because less trash is there
Note: Paper can only be recycled so many times as the
fibers lose strength
Radioactive Waste!!!
What is Radioactive Waste?
 It all started when the French physicist Henri
Becquerel (1896) accidentally discovered that some
isotopes undergo reactions that change the nuclear
form
 There are three common types of radiation
 Alpha
 Beta
 Gamma
Alpha Radiation
 An Alpha radiation an alpha particle, a positively
charged helium nuclei.
 These alpha particles have a low penetrating power,
only about a few centimeters of air and can be stopped
by clothing paper and skin.
Beta Radiation
 Beta radiation occurs in beta decay when a stream of
negatively charged electrons are expelled from an atom
 In beta decay, a neuton converts to a proton emitting
a beta decay in the process. The beta particle is
identical to an ordinary electron.
 Beta particles, electrons, can penetrate a few meters of
air, this is still only a moderate penetrating power.
Gamma Radiation
 Gamma rays are emitted if a nucleus still has excess
energy following decay and the emission of other
particles. They are electomagnetic in nature (called
photons), with a discrete, unique energy (this is used
to identify different radioisotopes).
 Photons are packets of energy, with wave like
properties. Photons make up light.
 Gamma rays are not physical particles, but their
interactions with matter are described by assigning
them particle-like properties.
 Gamma rays can penetrate 10cms of lead and up to a
couple meters of concrete
Radioactive Half lives
 Because of decay, all radioactive isotopes, eventually
brake down into other materials, when only half the
original substance is left, it has gone though 1 half-life
 Half-lives can range from milliseconds to billions of
years depending on the element and isotope
 To equate half lives use the equation:
Original Mass
= Remaining Mass
2^half life
Radioactive Waste Disposal
 There are three levels of waste storage, depending on
the type of decay it produces and the length of half life
 Low Level Waste
 Medium or Intermediate Waste
 High-level Waste
Low-Level Waste
 Holds 90% of nuclear waste, but is only responsible for
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about 1% of the radiation
Compacted to reduce volume, than buried in shallow
lined land-burial trenches
90% of this waste will return to background radiation
within 100 years.
This radioactive waste typically has only alpha and low
level beta radiation and short half-lives
Waste includes clothes, gloves, paper, products from
nuclear fuel cycle, hospitals and nuclear research
facilities
Mid-Level/ Intermediate Waste
 This waste is often stored in steel containers in
concrete vaults below ground
 Intermediate waste is used with intermediate levels of
beta decay, and with intermediate half-lives,
shockingly.
 This waste is produced from nuclear reactor parts and
processing nuclear fuel
High-level Waste
 Very small percentage of waste but is the biggest
contributor to radiation
 Must be stored for a very long time, which causes the most
problems
 Presently the best solution is to change the liquid waste into
glass, than burying deep underground in earthquake free
environments. Such as granite or salt mines.
 This waste is normally due to high beta or gamma radiation
with a long half-live
 High-level waste comes from spent fuel rods, and
processing of spent nuclear fuel
The End