This week, we were celebrating Earth Day all week with science activities to care for the Earth. First, we did a two day project – recycled paper. The first day, the students tore up scrap paper into small pieces then we allowed the paper scraps to soak overnight. For some interesting paper, you can add old jeans torn up with the paper. The next day, we blended the soaked paper. Then we pored the pulpy solution over some screens into some cookie cutter molds. The students used their hands to press the water out, which is a very important step in the process. We added some seeds and pressed some more. Then we moved the cookie cutter and pressed a piece of felt over the seed paper, pressing out more water. We allowed the paper to dry on the felt and the students each had a piece of recycled seed paper.
We learned about the effects of mining on the environment with chocolate chip cookies. The students each drew before and after pictures of their cookies, and an imagined habitat their cookie could represent. We talked about what animals and plants might grow in their imagined habitat. Then they used toothpicks to try to remove the chocolate chips. We thought about what this would mean for their habitat. We talked about how some places use water in the mining process and what effect that would have on the water and the habitat. While they ate their cookies, we thought about alternative methods we could use to get energy.
We performed some small demonstrations about wetlands and watershed areas. To represent a wetlands, we lined a tray with several damp sponges. Half the tray was left uncovered. When a flood of dirty water washed through the area, we watched as the dirty water was trapped in the wetlands. We used a second tray to represent a city that decided to expand over the wetlands. This tray had no sponges. When the flood of dirty water came, the city had no defense.
To create a wetlands, we crumpled up a piece of paper. Then we opened up the piece of paper without completely flattening it to represent mountains and valleys. We marked the ridges of the mountains with green markers and the students guessed where water might pool with blue markers. Finally, we used some brown markers to represent leaf litter, animal feces, and other natural and unnatural pollutants that might find their way into the water. We sprayed the mountains with a water bottle and watched as the colors blurred and traveled through the mountains. We noticed how the water gathered in certain areas, along with other things it may have picked up.
Finally, we created a water filtration system. We created some dirty water, then talked about the steps from the Home Science Tools example. We agitated the water by shaking the bottle, then allowed it to sit. We added some alum, then let it sit once again while we read The Magic School Bus at the Water Works. We looked for the steps we had done so far. After we finished the book, we used our cut bottle to build a filter. We turned the top half upside down in the other part of the bottle and laid a coffee filter on the bottom. You can choose items to put in the filter, from activated charcoal and sand to gravel. The students chose the order in which we added our filter items. Then we poured the water through the system, noting how much cleaner it appeared. We talked about how we missed the final step of disinfecting the water, so our water was not safe to drink. But it was much cleaner.