Soil contamination by hydrocarbons
The materials required for this science fair project:
- 80 green bean seeds
- 4 pots
- enough soil for the 4 pots
- 1 bottle of motor oil
- 1 packet of oil absorbing polymers
- 1 packet of water absorbing polymers
- A spade
- a black marker pen
1. For this science fair project, the independent variable is the soil content – normal soil, soil contaminated by motor oil, soil contaminated with motor oil but treated with the water absorbing polymer and soil contaminated with motor oil but treated with the oil absorbing polymer. The dependent variable is the number of green beans that germinate. This is determined by counting the number of seeds that geminate. The constants (control variables) are the size of the pot, the number of seeds in each pot, the amount of water, the amount of sunlight and the room temperature.
2. Four pots are labeled “soil”, “soil-oil”, “soil-oil-water polymer” and “soil-oil-oil polymer” accordingly. The soil in the pots is prepared as follows :
a. Soil : The pot is filled with soil only
b. Soil – oil : The soil is mixed with 100 ml of motor oil before filling the pot
c. Soil – oil- water polymer : The soil is mixed with 100 ml of motor oil and the water absorbing polymer is added to the soil
d. Soil - oil – oil polymer : The soil is mixed with 100 ml of motor oil and the oil absorbing polymer is added
Ensure that each sample is mixed and stirred thoroughly.
3. 20 green beans are placed in each of the 4 pots that were prepared as explained above. The beans were spread out at least 1 cm apart from each another.
4. The 4 pots are watered once a day and placed where they are able to receive enough sunlight and air in order to germinate.
5. The pots are observed for the next 10 days to ascertain the number of germinated beans and the results are recorded in the table given below.
Basic safety requirements. Discard the motor oil properly. Do not allow the motor oil to come into contact with bare skin.