Dissecting a Typical Lunchroom Garbage Can.
Background:
Solid waste disposal in the United States has become a large problem. According to the 2011 EPA
report on Municipal Solid Waste, American citizens generate 4.40 pounds of waste each per day of
which only 1.53 pounds of the material is composted or recycled(1). This waste generation is up 164 %
from the 2.68 pounds of waste generated per person in 1960. The good news is even with increased
generation has come an increased emphasis on recycling. In 1960 only 6% or 0.17 pounds of this
material was recycled, whereas today, 26% of solid waste is recovered. This rate of recycling, however,
still leaves the nation with a staggering 163 million tons of trash generated per year. In this waste
stream lies valuable materials; 11.07 million tons of steel, 2.75 million tons of aluminum, 29.19 million
tons of plastic, 8.30 million tons of glass, 24.12 million tons of paper products, and 49.32 million tons of
organic food scraps and grass clippings. All of these valuable materials are high quality matter which are
easier to acquire and require much less energy to purify than the initial raw resources of this matter, for
example, iron ore, aluminum ore, and petroleum products. In this lab we will investigate what you and
your fellow classmates discard and look to see how we can reduce the materials that flow through our
school’s waste stream.
Procedures:
CAUTION: Be cautious of sharp objects and any possible biohazard material. We will be working with
garbage, but remember, garbage 15 minutes ago was useful items and food.
1) Obtain gloves and aprons and wear them.
2) On a large tarp, pour out the contents of a single lunchroom trashcan.
3) Using the buckets provided, attempt to separate the materials found in the can.
Aluminum, Glass, Steel, Recyclable plastic, Non-recyclable plastic, Recyclable paper products, Nonrecyclable paper products, Food waste, and Other
4) Using the scales provided, mass all of the material recovered and place the data in the table below.
5) When finished, discard materials that must be sent to the landfill, recycle the aluminum, glass, plastic,
and steel, and compost the food waste and paper products.
Data Table:
Material
Aluminum
Glass
Steel
Recyclable
Plastic
Nonrecyclable
plastic
Recyclable
paper
Nonrecyclable
paper
Food waste
Other
Total Mass
Weight of
material kg.
% Material
by Mass
Notes on contents
Analysis:
1) What was the total mass, as a percentage of all mass, of the recyclable content found in the trashcan?
2) Describe the contents of the recyclable plastic materials what types of plastics were found? (give
specific types or recycling numbers if possible)
3) Describe the amount of aluminum found in the trashcan.
4) As of 12/01/13 the price of aluminum was $ 1.69 / kg. Assuming that all trashcans in both cafeteria
locations contained the same amount of aluminum what would the value of the 6 trashcans be per week
in aluminum alone?
5) What was the total mass, as a percentage of all mass, of the compostable content found in the
trashcan? (food waste and paper material)
6) What percentage by mass was the actual material that must be discarded in a landfill?
(1) - Municipal Solid Waste (MSW) in the United States: Facts and Figure
http://www.epa.gov/epawaste/nonhaz/municipal/pubs/MSWcharacterization_508_053113_fs.pdf