My third grade scientists continued their environmental labs with one that focused on oil spills. We began with a discussion about crude oil– how it is obtained and the many ways it is used. Vocabulary included petroleum, fossil fuel, and nonrenewable resource. We looked at pictures of the Alaskan pipeline, oil rigs, and oil tankers. That led us to a discussion of oil spills and their impact on marine life. We also observed that oil and water don’t mix and discussed why oil sits on the top of water. Does that make it easier or harder to remove the oil from the ocean water?
We brainstormed ways that we thought scientists might try to remove the oil. Then we investigated how difficult it is to remove oil from water using similar techniques tried by environmental engineers. We didn’t have crude oil, so we used vegetable oil mixed with cocoa.
First we tried to contain the oil with a Popsicle stick and string and then we attempted to skim the oil off the top of the water using a pipette and spoon. Next the students tried absorbing oil with a sponge and cotton ball. As they were working, I dropped a squirt of Dawn soap into their oil spill. The oil dispersed. I explained that scientists have used dispersants to help break oil into small droplets, but the oil sank to the ocean floor where it was more difficult to remove. We dipped feathers into the oil to investigate how oil adheres to a bird’s feathers. In two of the classes, we washed off the feathers with Dawn soap.
Look at this invention that effectively removes oil from water. Click here to see it at work. After trying themselves to remove oil from water, they were amazed by this product. I also demonstrated a polymer that changes the oil into a solid. Click here to watch the investigation.