Fast to Make Last to Break

By Mary Neufeld
Junior Category (Grades 7-8)
Experiment | Environment

Background, Purpose, Hypothesis:
Decomposition is a simple and effective way to not only create rich soil, but to reuse old items in the process. When certain items are buried in soil for a prolonged period of time, they start to break down. For effective decomposition, items must be placed in the right environment. Heat, oxygen, and microorganisms are essential for successful decomposition. But, even with these conditions, some materials still take hundreds of years to decompose. Some materials are even said to never decompose. The purpose of this experiment is to discover which common fast food packaging materials decompose the quickest when being fully submerged in soil for 6 weeks. The materials I tested in this experiment were bagasse, styrofoam, cardboard, wax paper, plastic (cup and straw), and paper (cup and straw), which are all commonly used in the fast food industry. My hypothesis was that the paper straw would decompose the quickest.

Before starting this experiment, I weighed each sample so that when I dug up my samples after six weeks, I would be able to compare the weight loss of each sample to see how much they had each decomposed. To start my experiment, I placed three inches of soil in the bottom of seven identical buckets. I placed each sample in the middle of its own bucket (both the plastic straw and paper straw were placed into the same bucket, on either side, for convenience.) Each sample was then covered fully with another three inches of soil. The buckets were then left for six weeks, in a fairly sunny location, so they would receive as much heat as possible. After six weeks, each sample was dug up and left to dry for a week. Once dry, the samples were then weighed again to decipher which material(s) had lost the most weight throughout this experiment.

Results, Conclusions, Applications:
This experiment proved that paper (specifically the paper cup), and cardboard (specifically the cardboard container), decompose the quickest compared to other commonly used packaging materials. However, other materials such as wax paper (wax paper sleeve), and bagasse (bagasse clamshell container) do decompose, but not as quickly as cardboard and paper. I also discovered that the plastic and styrofoam containers did not decompose at all. The results of this experiment could be applicable to fast food companies and other industries who are trying to create environmentally friendly products. By creating products that have a quick decomposition rate, items that do not make it to the landfill will still be safe for the environment. After conducting this experiment, I feel more aware of my usage of plastic waste, and would like to continue my research in how to prevent waste buildup.

I would like to thank both of my parents for supporting me while I conducted my experiment. I would also like to thank my teacher for pushing me to reach my full potential in this project.

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