Acid Rain Lab: Logan, Sam, Julianne, Christina, Kylee
Introduction:
According to the EPA, "Acid rain is a broad term referring to a mixture of wet and dry deposition (deposited material) from the atmosphere containing higher than normal amounts of nitric and sulfuric acids." Acid rain is formed when gases, sulfur dioxide and nitrogen oxides, react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds, resulting in sulfuric acid and nitric acid. Both sulfur dioxide and nitrogen oxides enter the atmosphere naturally and anthropogenically. These gases enter the atmosphere naturally by way of volcanoes and decaying vegetation and anthropogenic sources such as being emitted from industrial sources, energy generation, and automobiles. Acid rain can be detrimental to ecosystems, particularly plant life. "After much analysis, researchers now know that acid rain causes slower growth, injury, or death of forests. Acid rain has been implicated in forest and soil degradation in many areas of the eastern U.S. Acid rain does not usually kill trees directly. Instead, it is more likely to weaken trees by damaging their leaves, limiting the nutrients available to them, or exposing them to toxic substances slowly released from the soil. Quite often, injury or death of trees is a result of these effects of acid rain in combination with one or more additional threats.(EPA)" In this experiment however, we will be assessing how acid rain affects the size, growth, and color of fescue grass.
According to the EPA, "Acid rain is a broad term referring to a mixture of wet and dry deposition (deposited material) from the atmosphere containing higher than normal amounts of nitric and sulfuric acids." Acid rain is formed when gases, sulfur dioxide and nitrogen oxides, react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds, resulting in sulfuric acid and nitric acid. Both sulfur dioxide and nitrogen oxides enter the atmosphere naturally and anthropogenically. These gases enter the atmosphere naturally by way of volcanoes and decaying vegetation and anthropogenic sources such as being emitted from industrial sources, energy generation, and automobiles. Acid rain can be detrimental to ecosystems, particularly plant life. "After much analysis, researchers now know that acid rain causes slower growth, injury, or death of forests. Acid rain has been implicated in forest and soil degradation in many areas of the eastern U.S. Acid rain does not usually kill trees directly. Instead, it is more likely to weaken trees by damaging their leaves, limiting the nutrients available to them, or exposing them to toxic substances slowly released from the soil. Quite often, injury or death of trees is a result of these effects of acid rain in combination with one or more additional threats.(EPA)" In this experiment however, we will be assessing how acid rain affects the size, growth, and color of fescue grass.
Hypothesis: If we water three different samples of grass with one being pure H20, and two with varying degree of acidity, then the grass that is being watered with pure H20 would experience the best results while the samples watered with the most acidic solution would experience negative results.
Parts of the Experiment:Experimental Group: Bottle B and Bottle C -pH of 3 and 1.5 respectively
Control Group: Bottle A-pH of 6 (Regular Water)
Independent Variable: the pH level of the water
Dependent Variable: The appearance and the growth of the grass
Control: Amount of sunlight, temperature, the amount of water given to each plant, the amount of time each plant was exposed to the "acid rain"
Materials:
Methods:1. Label bottles "A", "B", "C"
2. Trim the three bottles of grass to the same height. In this particular experiment the three bottles of grass were trimmed to 2 inches.
3. Record observations of the grass
4. Find the pH of the three different waters to be sure there is one with a pH of 6, 3, and 1.5
5. Pour: 100mL of the water with a pH of 6 into bottle A, 100mL of the water with a pH of 3 into bottle B, 100mL of the water with a pH of 1.5 into bottle C
6. Repeat this process every other day for two weeks
7. After two weeks, record observations of the grass including appearance and growth
Data:
Control Group: Bottle A-pH of 6 (Regular Water)
Independent Variable: the pH level of the water
Dependent Variable: The appearance and the growth of the grass
Control: Amount of sunlight, temperature, the amount of water given to each plant, the amount of time each plant was exposed to the "acid rain"
Materials:
- 3 two-liter bottles, halfway cut open
- Grass planted in each of the two liter bottles, for this experiment the same grass that was used in the Erosion Lab was used.
- Graduated Cylinder
- Water with a pH of 6, 3, and 1.5 (pH changed by Mr. Gunsher)
- Scissors
- Ruler
Methods:1. Label bottles "A", "B", "C"
2. Trim the three bottles of grass to the same height. In this particular experiment the three bottles of grass were trimmed to 2 inches.
3. Record observations of the grass
4. Find the pH of the three different waters to be sure there is one with a pH of 6, 3, and 1.5
5. Pour: 100mL of the water with a pH of 6 into bottle A, 100mL of the water with a pH of 3 into bottle B, 100mL of the water with a pH of 1.5 into bottle C
6. Repeat this process every other day for two weeks
7. After two weeks, record observations of the grass including appearance and growth
Data:
Data Analysis:
Making it clear, the control group was supposed to be watered with distilled water; however, the water used had a pH of 6 instead of 7. The data of this experiment supported parts of the hypothesis. Going into the experiment, the expected results was that the control group would experience the most positive results while the slightly acidic would experience gentle negative results and the group with the most acidic would experience the worst results. After the experiment, the group with the pH of 1.5 experienced the most negative results, but the group with the pH of 3 experienced the best results. The control group did experience positive results but did not grow as much as the group with a pH of 3. The results of the experiment showed that group B experienced the most growth, followed by group A, and lastly group C which experienced the most negative results. Looking at this lab you are able to conclude that acid rain has a negative effect on the growth of fescue plants. The general trend shown is that the grass with any concentration of acid decreased in length. The grass without any concentration of acid was able to increase in length (the control group). Looking at other groups results and looking at their plants, you can see the correlation that grass with high concentrations of sulfuric acid have a brownish color down towards the roots.
The negative results that the grass experienced consisted of not growing, dying, or thinning out. Group A experienced 1.5 inches of height growth, decrease in thickness, and medium root length. Group B experienced 2 inches of height growth, no decrease in thickness, and long root length. Group C experienced no growth, a decrease in thickness, short root length, and brown colored tips.
Another group used three different marigold plants with the same three different pH levels of water that were used in this particular experiment. It appears from that data that the results of the marigolds were similar to that of the grass. The water with the highest pH was most damaging to the plant whereas the water with a pH of 3 seemed to increase growth more than the water with a pH of 6 did.
Conclusion:
After completing the experiment, I found that our results supported some, but not all of our hypothesis. There was decreased height of the plants after applying the acid rain, and there was visible death occurring at the roots of the plants because of the lowered pH in the soil. The group with slight amounts of acid in their water caused the greatest positive results while the group with the highest acidity concentration experienced the greatest negative results. This suggests that small amounts of acid can stimulate plant growth while too much can harm its health. An increase in exposure to such chemicals may yield slightly different results. For example, our Group B may survive with slight acid content for a few weeks but may steadily die after a month or so. We conducted this experiment for about two weeks so we are only able to conclude that after this amount of time, slight acid promotes growth and strong acids kill the grass.
After seeing the resistance of Fescue, I have concluded that this grass would be good for planting in cities and highly industrial areas as well as areas were grass has trouble growing because acid rain or other growth inhibitors. Fescue is a plant that takes a long time to be affected by acid rain and does not suffer significant effects, especially if it is taken care of a lot. The EPA's study on acid rain in the United States shows that the acid rain that falls in the United States is typically in between 4.0 and 5.0; in this case, the water with 10% concentration of acid is the most realistic depiction of the type of acid rain Fescue would have to go through in the United States.
Overall, the acid rain lab has presented another obvious reason the world needs to decrease the burning of harmful fossil fuels. Grassstitcher.com points out that acid rain affects lawns mostly in the eastern United States because of soil and grass type. The website also reveals that when acid rain infiltrates soil one way to "buffer" the pH back up is through the use of fertilizers. This presents another reason to stop acid rain because we have learned the use of fertilizers can cause water pollution from runoff and other related problems.
Citations:
"Grasstitcher." National Geographic. National Geographic, n.d. Web. 12 Dec. 2013.
"Effects of Acid Rain." EPA. Environmental Protection Agency, n.d. Web. 11 Dec. 2013.
Making it clear, the control group was supposed to be watered with distilled water; however, the water used had a pH of 6 instead of 7. The data of this experiment supported parts of the hypothesis. Going into the experiment, the expected results was that the control group would experience the most positive results while the slightly acidic would experience gentle negative results and the group with the most acidic would experience the worst results. After the experiment, the group with the pH of 1.5 experienced the most negative results, but the group with the pH of 3 experienced the best results. The control group did experience positive results but did not grow as much as the group with a pH of 3. The results of the experiment showed that group B experienced the most growth, followed by group A, and lastly group C which experienced the most negative results. Looking at this lab you are able to conclude that acid rain has a negative effect on the growth of fescue plants. The general trend shown is that the grass with any concentration of acid decreased in length. The grass without any concentration of acid was able to increase in length (the control group). Looking at other groups results and looking at their plants, you can see the correlation that grass with high concentrations of sulfuric acid have a brownish color down towards the roots.
The negative results that the grass experienced consisted of not growing, dying, or thinning out. Group A experienced 1.5 inches of height growth, decrease in thickness, and medium root length. Group B experienced 2 inches of height growth, no decrease in thickness, and long root length. Group C experienced no growth, a decrease in thickness, short root length, and brown colored tips.
Another group used three different marigold plants with the same three different pH levels of water that were used in this particular experiment. It appears from that data that the results of the marigolds were similar to that of the grass. The water with the highest pH was most damaging to the plant whereas the water with a pH of 3 seemed to increase growth more than the water with a pH of 6 did.
Conclusion:
After completing the experiment, I found that our results supported some, but not all of our hypothesis. There was decreased height of the plants after applying the acid rain, and there was visible death occurring at the roots of the plants because of the lowered pH in the soil. The group with slight amounts of acid in their water caused the greatest positive results while the group with the highest acidity concentration experienced the greatest negative results. This suggests that small amounts of acid can stimulate plant growth while too much can harm its health. An increase in exposure to such chemicals may yield slightly different results. For example, our Group B may survive with slight acid content for a few weeks but may steadily die after a month or so. We conducted this experiment for about two weeks so we are only able to conclude that after this amount of time, slight acid promotes growth and strong acids kill the grass.
After seeing the resistance of Fescue, I have concluded that this grass would be good for planting in cities and highly industrial areas as well as areas were grass has trouble growing because acid rain or other growth inhibitors. Fescue is a plant that takes a long time to be affected by acid rain and does not suffer significant effects, especially if it is taken care of a lot. The EPA's study on acid rain in the United States shows that the acid rain that falls in the United States is typically in between 4.0 and 5.0; in this case, the water with 10% concentration of acid is the most realistic depiction of the type of acid rain Fescue would have to go through in the United States.
Overall, the acid rain lab has presented another obvious reason the world needs to decrease the burning of harmful fossil fuels. Grassstitcher.com points out that acid rain affects lawns mostly in the eastern United States because of soil and grass type. The website also reveals that when acid rain infiltrates soil one way to "buffer" the pH back up is through the use of fertilizers. This presents another reason to stop acid rain because we have learned the use of fertilizers can cause water pollution from runoff and other related problems.
Citations:
"Grasstitcher." National Geographic. National Geographic, n.d. Web. 12 Dec. 2013.
"Effects of Acid Rain." EPA. Environmental Protection Agency, n.d. Web. 11 Dec. 2013.