Polypropylene Absorbent Pads Science Fair Projects

PURPOSE

The purpose of this experiment was to determine the effect of salinity on the ability of polypropylene absorbent pads to pick up oil spills.

I became interested in this idea when I learned that oil spills are a problem in society. I wanted to test whether there is a difference in fresh water or saltwater recovery of the oil.

The information gained from this experiment could help society because spilled oil is a huge and growing problem. Oil pollutes fresh water streams and lakes as well as marine areas. We need to know ways to recover spilled oil before it causes environmental damage.

Young Scientists Set 1	EDU 8650 Ecology Science Kit	PicoTurbine Windmill
Ages 5 -8	Ages 10 and up	Age 10 thru college

Polypropylene is a versatile polymer and is both a plastic and a fiber. As a plastic it's used to make things like dishwasher-safe food container because it doesn't melt below 160oC, or 320oF. As a fiber, polypropylene is used to make indoor-outdoor carpeting that is often found around swimming pools and miniature golf courses. It works well for outdoor carpet because it doesn't absorb water like nylon does.

HYPOTHESIS

My hypothesis was that as the salinity level increased the polypropylene absorbent pads would pick up more oil.

I based my hypothesis on the fact that saline water is denser then fresh water. So the oil would rise to the top faster in the saline water than in the fresh water. More oil on the surface might mean polypropylene absorbent pads would pick up more oil.

EXPERIMENT DESIGN

• The type of polypropylene absorbent pads
• The type of oil
• Amount of oil
• Size of polypropylene absorbent pads
• Temperature of water
• The container used to hold the water and oil

MATERIALS

PROCEDURES

1. Prepare polypropylene pads
A) Cut each polypropylene pad into eighths
B) Weigh each polypropylene pad
C) Mark the weight on the corner of each pad
2. Prepare salt water. Only one of the mixtures will be used in each test.
A) Clean the bucket
B) For the control group pour 5000 ml. of tap water into the bucket
C) For the brackish water group (17.5 g/l)
i. pour 4912.5 of tap water into the bucket
ii. add 87.5 grams of salt
iii. mix well for 3 minutes using an electric drill with a paint-stirring rod.
D) For the ocean water group (35 g/l)
i. pour 4825 ml. of tap water into the bucket
ii. add 175 grams of salt
iii. mix well for 3 minutes using an electric drill with a paint-stirring rod.
3. Add 100 ml. of motor oil to the water or salt water being tested.
A) Mix well for 3 minutes using an electric drill with a paint-stirring rod.
B) Let sit 15 minutes
4. Recover oil with polypropylene pads.
A) Place a pad onto the surface and let it float for 15 min.
B) Remove this pad and let it dry.
C) Place a second pad onto the surface and let it float for 15 minutes
D) Dry polypropylene pads
5. Weigh the pads separately using a triple beam balance and record on a data sheet.
6. Repeat steps 2 – 5 for a total of three trials with the same salt-water mixture.
7. Repeat steps 2 – 6 with the next salt-water mixture.
8. Find the average of the different trials for each salt-water group.

RESULTS

The original purpose of this experiment was to determine the effect of salinity on the ability of polypropylene absorbent pads to pick up oil spills.

The oil was collected from the water in three passes. For all three treatments the first pad collected about three times as much as the second pad, which collected about twice as much as the third pad. The total for all three pads was the most useful data.

The results of the experiment showed that all three treatments were nearly the same. The fresh water group collected an average of 81.1 grams of oil, the brackish water collected 80.7 grams, and the salt water collected 81 grams.

CONCLUSION

My hypothesis was that as the salinity level increased the polypropylene absorbent pads would pick up more oil.

The results indicate that this hypothesis should be rejected because there was almost no difference between the groups. In fact the fresh water group was .01 gram higher than the highest salinity group.

Because of the results of this experiment, I wonder if collecting the oil immediately after mixing it into the water without giving it time to separate would change the amount absorbed for each group. Another interesting question would be to test the effect of water temperature on oil recovery. The oil I used was highly refined, so it would be valuable to test crude oil recovery.

If I were to conduct this project again I would make sure that the times I took the pads out of the bucket were more exact. I would also use more pads so there was no oil left in the bucket at the end of each trial. Another improvement would be to find a more efficient way to pour the oil into the bucket because the oil got stuck to the sides of the graduated cylinder, so not all of the oil got into the bucket. The last difference would be to do more trials to make sure my results were reliable.