Various cultures throughout history have attempted many different water purification methods. Students can complete a project not only to help them learn about water purification, but about some cultural customs and ideas as well. Students will compare the ancient water purification methods of Japanese, German, African and American cultures. To begin, students must obtain water that is not clean and separate it into four samples. Then, students must test the samples to obtain initial bacteria levels. Next, students must try each of the following methods: boiling (the Americas); use of Moringa Olefeira seeds placed in water (African); the addition of iodine to the water (German); the addition of scallop shells into the water (Japanese). Once complete, students can test each sample again and determine which, if any, of these methods was most effective.
Students can do a project to compare the purification of water using hydrogen peroxide, vinegar, light and darkness. Students should collect four samples and do initial bacteria tests. Then, students should add hydrogen peroxide to one sample and vinegar to another, and place the water in a place that is not too bright, nor too dark. Students can place the other two samples in a bright area and a very dark area respectively. After 48 hours, students should test the water samples once more for bacteria to see if any of these methods were effective.
Another fun project focuses specifically on the removal of oil from water, such as after an oil spill. Students should collect water in two separate basins. Next, students should dye vegetable oil a dark color with food coloring so that it can be better seen during the science experiment. Then students should compare which method is more effective in removing the oil: a sponge used to absorb the oil or a spoon used to take the oil from the top of the water. To determine which method was effective, students can squeeze the oil from the sponge into one measuring cup and dump the oil from the spoon into another to compare which method netted the most oil.
By doing a project using a water filter, students will be able to see how a filter works to purify water. Students should use a two-liter bottle cut in half, gravel or sand, and napkins or cotton balls. They will also need water that is contaminated with an easy-to-find household material such as oil. Students should stuff the top half of the two-liter bottle with the cotton balls, napkins, and gravel or sand. Then, the contaminated water can be poured from a pitcher through the "filter" into the bottom half of the two-liter bottle. Students should be able to see how the filter keeps impurities from reaching the other side.