Cleaning the Water
For years in school, I have learned that out of all the water on Earth, there is only about 0.7% available as fresh drinkable water. I live on a farm, and I understand that water is one of the most precious resources. I fully appreciate the luxury of "clean" water and often wonder if there is a way to filter the contaminated poultry house water that stands outside the chicken houses. I believe there may be a way to build the poultry houses on materials that would filter the contaminated water.
I hypothesized that by using sand to filter the water, the sand would lessen the pollutants being released into the environment. In preparing for this experiment, I needed to find all the information I could about environmental water issues. With only a basic comprehension of the water cycle, I wanted to understand more about our town's primary water source and the treatment of the water. The background information for this project came from interviewing poultry farmers and experts who deal with contaminated water, as well as Internet research. Through this background research, I obtained a wealth of information regarding the water system and the water purification process.
The experts I interviewed told me that I should test the water for pH, nitrate level, and phosphate level. Of course, I live on a farm and I wanted to use chicken litter to "contaminate" the water. I came up with the idea that I would use different types of soil to filter the contaminated water. I thought that the information gained from this experiment could be used to help future poultry farmers in the construction of their farms. At this point, the only thing left to do was plan the experiment.
Once I had a plan, I had to prepare my materials for the testing process. I had to collect soil samples from the local soil conservation district. The five different soil samples that I chose were sand, red clay, ash, gravel, and loam. The soil samples were dried and tested for pH, nitrate level, and phosphate level. Then I used filtered tap water to wash the soil samples and make sure that there were no nitrates or phosphates in the soil. Once the soil had been washed several times with clean filtered water, the water was tested to make sure the pH, nitrate, and phosphate levels were not detectable.
I began collecting water samples. The first part of the process was to test the water that would be filtered for temperature, pH, nitrate level, and phosphate level. A mixture of chicken litter and water was made, and I let it sit for two weeks. Each mixture consisted of 600 ml of water and 500 ml of chicken litter. The mixture was tested again for temperature, pH, nitrate level, and phosphate level, and I recorded the results. Once these tests were performed and recorded, 250 ml of the mixture was filtered through the soil samples into jars.
I almost forgot to check the coffee filters. To ensure that the coffee filters were not responsible for removing the contaminants, five different jars with only coffee filters were tested. The jars were set up with only the soil samples missing, and 250 ml of the contaminated water was filtered through. The results were that pH, nitrate levels, and phosphate levels remained the same in the water as before the filtration.
Finally I was ready to experiment on the soil samples. I asked my science teachers if I could use a 125 ml beaker, a 250 ml graduated cylinder, 12 small funnels, and a water testing kit that included the supplies to test for pH, nitrate level, and phosphate levels. Then I had to make sure each jar was clean, and a clean plastic funnel was placed in the mouth of each jar. I then put a coffee filter in place, making sure to leave an area for the soil. Fifty ml of one soil sample was placed in the filter, and I made sure the soil sample was level for the surface area I needed. Slowly, I poured 250 ml of contaminated litter water through the soil sample. Once this was done, I set each jar aside to allow the water to filter through the soil sample. Then I placed the lid on the jar and shook the sample of filtered water. After three hours, I tested each sample for pH levels, nitrates levels, and the phosphate levels. My method for determining the amount of particles in my samples was fairly straightforward.
In order to analyze my data, I made graphs to show the levels of contaminates. The original purpose of this experiment was to see how well different types of soils would filter contaminated water. The results turned out to be very interesting. I have included the graphs I made for the experiment.
The contaminated water was found to have a pH of 8. After running the contaminated water through the different filters, the pH remained the same with the ash, clay, dry filter and sand. The contaminated water's pH levels dropped to 7 with both the gravel and the loam.
The phosphate levels in the contaminated water were found to be around two parts per million. After running the contaminated water through the ash, clay, dry filter, gravel and sand, the phosphate levels remained the same. The contaminated water's phosphate levels dropped to around zero parts per million with the loam.
The nitrate levels in the contaminated water were found to be around 2.5 parts per million. After running the contaminated water through the different filters, the nitrate levels remained the same except for loam. The contaminated water's nitrate levels dropped to around zero parts per million with the loam. The gravel also filtered a small amount of the nitrates from the water. The gravel tests showed that the nitrate levels dropped to two parts per million.
Though this project was conducted in jars and with limited resources, I found that the information gained was very relevant to environmental issues in my own backyard. The data that I gathered during this investigation was not what I had expected. The results of this experiment show how different types of soil filter contaminated water. Initially I had hypothesized that the sand would filter the contamination from the water. I based this on prior knowledge of filtration systems. After conducting this experiment, I now know that the loam soil from the A horizon filtered the contamination better than any of the other types of soil. I hope that the information gained from this experiment can be used to help future poultry farmers in their construction of their farms.
In reflecting on this experiment, I find myself motivated to research this issue further. I have obtained simulated Martian soil, known as JSC Mars-1, from NASA's Johnson Space Center. The coarse cinnamon-colored powder closely resembles the red dirt found on the surface of Mars. Its characteristics are very similar to what scientists know about the color, density, grain size, porosity, and chemical composition of Martian soil. I plan to compare the characteristics of the JSC Mars-1 soil to the characteristics of soil types found here on Earth. I am also studying ways of using JSC Mars-1 soil for the filtration of possible contaminates. At this time, I am working on building a filtration system that may be helpful to astronauts traveling to Mars.
Jones, Greg. Nashville Water Department. Interviewed by Hunter Anderson, 12 Sep 2009.
Lovett, Richard. "Soil Resembles Veggie-Garden Dirt, Lander Finds." National Geographic News. Retrieved from the World Wide Web on 29 Sep 2009. http://news.nationalgeographic.com/news/2008/06/080626-mars-lander.html
Riskowski, Jodi. "An Activity to Develop Water-Quality Awareness." Science Scope (May 2009): 34-37.
Williams, Becky. Natural Resource Conservation Service. Interviewed by Hunter Anderson, 5 Sep 2009.
More About This Resource...
This winning entry in the Museum's Young Naturalist Awards 2010 is from an Arkansas ninth grader. Hunter experimented with soil filtration systems. His essay discusses:
- his motivation to determine if he could find a way to filter contaminated poultry house water
- the experiment he set up and what he tested the soil samples for
- how his results conflicted with what he had expected
Supplement a study of ecology with an activity drawn from this winning student essay.
- Send students to this online article, or print copies of the essay for them to read.
- As a class, discuss the importance of fresh drinkable water. What are some of the ways water is contaminated? What are some of the contaminates that home water filtration systems remove?
OriginYoung Naturalist Awards
SubtopicMinerals and Resources