Decomposition of bio-degradable plastic spoons
The materials required for this science fair project:
- 10 pieces corn starch based bio-degradable spoons
- 10 pieces wheat-based bio-degradable spoons
- 10 pieces plastic spoons
- 1 digital weighing scale
- Soil, or a garden plot
- A black marker pen
1. For this science fair project, the independent variable is the type of spoon used ? corn starch based, wheat based and plastic. The dependent variable is the amount of decomposition observed after 30 days. This is determined by using the digital weighing scale to measure the weight of the spoons before and after the 30 days. The constants (control variables) are the type of soil used, the length of time allowed for decomposition, the temperature and humidity.
2. 10 pieces of each of the corn starch-based bio-degradable spoons, wheat-based biodegradable spoons and plastic spoons are marked accordingly, as ?corn?, ?wheat? and ?plastic?.
3. The total weight of each type of spoon is checked using the digital weight scale. The total weight for the 10 spoons is divided by 10 to obtain the average spoon weight. The values are recorded in the table given below.
4. The spoons are then planted inside a pile of garden soil and left there for 30 days to decompose. Ensure that each spoon is surrounded entirely by soil, and ensure that soil from the same bag/garden plot is thoroughly mixed, and used to cover all of the spoons. The soil is watered daily to keep it moist. After the 30 days, the spoons are removed from the soil and cleaned under tap water. The spoons are then allowed to dry in the sun for a day.
5. The average weight of the spoons is again calculated as described in procedure 3 and the results are recorded in the table below.
Basic safety requirements