Millions of gallons of oil are transported across large bodies of water every week and spills occur in oceans with environmentally catastrophic results. Usual methods for cleaning up oil spills are either by polymers or by natural extraction. In Claudia Zeiger et al's experiment, “Microstructures of superhydrophobic plant leaves - inspiration for efficient oil spill cleanup materials" they found plants with trichomes whose ends are connected absorb the most oil, and trichomes with separate trichomes have less absorbance. Based on Ziegler's results with Salvinia, my goal was to find a land plant that could match or exceed Salvinia's absorption rate. I hypothesized that the hydrophobic behaviors of Salvinia would allow better absorption than the land plants tested alongside it: Licorice Plant, Dusty Miller, and Lamb's Ear.

Salvinia, Lamb's Ear, Licorice Plant, and Dusty Miller were selected for further scale up studies. Plant matter would be weighed (generally 1-3 grams of leaves), and then the oil calculated based on Motor Oil density (0.766 g/mL). Lamb's Ear and Salvinia showed the lowest absorption rates at 29% and 35%. Dusty Miller and Licorice Plant were the most successful with absorption rates at 77% and 63%. In later studies, only the land plants were tested in a saline solution (35% salt mixed with distilled water to mimic ocean environments) in amounts of 1-15 times the mass of the leaves in Motor Oil. A controlled time of five minutes and consistent stirring was used in all experiments throughout data collection. The oil soaked leaves were extracted, and put into a new beaker with tap water set aside for 48 hours to stir and release oil. The leftover water in the tank was filtered through filter paper to measure the oil absorbed.

My results showed that not only did Salvinia absorb a large amount of Motor Oil, but land plants showed significantly greater absorption rates. When testing the land plants in saline solution on a larger scale, they all had positive results. Dusty Miller had an absorption rate of 83%, Licorice Plant absorbed 81%, and Lamb's Ear increased absorption to 71%. Specifically, Dusty Miller and Licorice Plant showed to be very strong contenders for oil spill clean up:

r, Licorice plant is more plentiful around the US and it is cheaper to purchase at one gallon ($6.98) when Dusty Miller is $11.27. Thus, extended studies were done with Licorice Plant in 1-15 times the mass of its leaves in motor oil to see how effectively it could absorb large amounts of oil. The results showed that leaves exposed to oil 10 times their weight absorbed 90% of the oil.

Finding a way to get the leaves out of the water and then extracting the oil from the leaves will be the next step. Extracting the oil back out of the leaves will allow the leaves to be decomposed and left over oil to be contained, filtered, and then reused. This would further develop and encourage the environmentally friendly aspect of this project.