The Effects of Various pH Levels on the Phososynthesis Process of the Aquatic Plant Elodea.
Researched by Nichole A. 2000-01	PURPOSE  HYPOTHESIS  EXPERIMENT DESIGN  MATERIALS  PROCEDURES  RESULTS  CONCLUSION  RESEARCH REPORT  BIBLIOGRAPHY ACKNOWLEDGEMENTS ABOUT THE RESEARCHER

The purpose of this experiment was to determine how different pH levels of acidic and basic pollution solutions affected the amount of oxygen produced by plants in the process of photosynthesis.
I became interested in this idea when one of my best friends decided to add plants to her aquarium, however she has an outdoor tank and she wanted to know if the pollutants around her house would kill the plants she fills the tank with.

The information gained from this experiment will benefit all aquarium owners and aquatic plant growers. I believe that these results will help factories reduce the amount of acid rain produced by their companies.
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My first hypothesis was that as the amount of acid varied farther from neutral (pH = 7) the less oxygen would be produced by the plants’ photosynthesis process. 

My second hypothesis was that as the amount of alkalinity varied farther from neutral (pH = 7) the less oxygen would be produced by the plants’ photosynthesis process.

I base my hypothesis on a statement taken from Encarta Encyclopedia Deluxe 2001 Edition that states "acid rain…makes lakes uninhabitable for wildlife."
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The constants in this study were:
-Amount of light 
-Amount of water 
-Bio-mass of plant tested in each trial 
-Amount of solution put in each beaker 

The manipulated variable was the pH level of the substances used.

The responding variable was the amount of oxygen produced by the process of photosynthesis.

To measure the responding variable the researcher measured the volume of the oxygen produced by the plant. 
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The original purpose of this experiment was to determine how different pH levels of acidic and basic pollution solutions affected the amount of oxygen produced by plants in the process of photosynthesis

The results of the experiment were that the plants in pH 6.0 produced 1 mL of oxygen, the plants in pH 6.4 produced 2.1 mL of oxygen, the plants in pH 7.0 produced 3 mL of oxygen, the plants in pH 7.6 produced 0 mL of oxygen, and the plants in pH 8.0 produced 0 mL of oxygen.

See the table and graph.

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My first hypothesis was that as the amount of acid varied farther from neutral (pH = 7) the less oxygen would be produced by the plants’ photosynthesis process. 

My second hypothesis was that as the amount of alkalinity varied farther from neutral (pH = 7) the less oxygen would be produced by the plants’ photosynthesis process.

The results indicate that the first hypothesis should be accepted and the second should be rejected

Because of the results of this experiment, I wonder if the color of the light would affect the amount of oxygen. I also wonder if the ammonia’s ingredients affected the plants rather than it’s pH. 

If I were to conduct this project again I would let the plants photosynthesize longer, use more trials, and have more grams of plant per trial.  Also I would not let the plant sit for as long before the trial was held.
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RESEARCH REPORT INTRODUCTION The purpose of this document is to explain the fundamentals of the effect of air pollution on many types of aquatic plants. The main topics in this report will be plants, air pollution, and pH.  PLANTS  Introduction to Plants  Plants can grow almost everywhere and are necessary to life’s processes. They are believed to be the oldest living organisms on Earth. There are 260,000 known species around the world, however this number is not accurate due to the fact that many types of plants are microscopic and cannot be studied.  PHOTOSYNTHESIS  Photosynthesis is the process by which plants produce their food. In this process sunlight is captured by chlorophyll, a substance in the cell of the plant. This sunlight enables carbon dioxide to unite with the water and minerals which have been absorbed into the plant by the roots. This union creates food for the plant and releases oxygen.  PARTS OF PLANTS Roots  Roots grow under ground to anchor the plant in the soil. As they grow, they expand to better absorb water and minerals.  One other job the root of the plant has is to store any excess food that is produced. Stem Each species of plant has it’s own type of stem which can vary greatly between plants. However in most plants the stem makes up the largest portion of the plant. Leaves  Like the stem, leaves vary among species. They differ in size, shape and color. On most plants the leaves are arranged in a definite pattern. Also this is where  the process of photosynthesis occurs.  AQUATIC PLANTS  Introduction to Aquatic Plants  Aquatic plants grow under or submerged in water. Most aquatic plants can survive varying water conditions, however pollution is a major problem.  CLASSIFACATION GROUPS   There are four aquatic plant classification groups. They are  I. Plants that float freely on or above the surface with no contact with soil II. Leaves of the plant float with the roots of the plant in the soil III. Root of the plant in soil with stalks above the water. IV. Roots of the plant in the soil with stem, leaves and flowers above the surface of the water. ELODEA  This type of aquatic plant is commonly known as waterweed.  They grow completely submerged in water. This species of plant is used in aquariums to help increase the oxygen level.  AIR POLLUTION INTRIDUCTION  Air pollution occurs every day in modern society. Air pollution is classified as contamination of air through smoke and exhaust. This contamination occurs when industry and vehicles put gas and particulates into the air. Most air pollution has the potential to be hazardous to animal and plant life.  OUTDOOR AIR POLLUTION  There are millions of tons of gas and particulates poured into the air each year. This is a result of industrial burning of fossil fuels. The most common types of outdoor air pollution are smog and acid rain. ACID RAIN  Acid rain begins as a chemical compound, sulfur dioxide, SO2, which then mixes creating a compound of H2SO4. As the mixture reaches high altitude it cools and condenses returning to the earth in the form of rain or snow. This compound causes widespread damage due to it’s chemical reaction with things it comes in contact with. pH INTRODUCTION TO pH  pH is a number scientists use to indicate the concentration of hydrogen ions.  pH was invented by biochemist SØren SØrensen who invented a pH meter to measure the level of pH. The pH meter measures a range of 1-14 with 7 being neutral. pH stands for potential hydrogen.  ACID  Acid is classified as a group of chemical compounds with similar properties. Some acids are essential to life’s processes and occur naturally. Acids neutralize bases or alkaline substances. They have a pH coordinate lower than seven. BASE  Base is a chemical compound that yields hydrogen ions. They are also defined as substances that can be combined with a proton. Bases also neutralize acids. They are used in many household items such as ammonia. These substances have a pH coordinate higher than seven. SUMMARY The facts on air pollution, plants and their pH content could prove beneficial to the general population but more specifically marine biologists and water chemists.  Back to Top

BIBLIOGRAPHY Armbuster, David. "Ammonia," World Book Encyclopedia, 1998, volume 1 Chertow, Marian. "Environmental Pollution," World Book Encyclopedia, 1998, volume 6, pages 331-334  DeMichele, William, "Plants," World Book Encyclopedia, 1998, volume 15 pages 516-545 "Elodea," World Book Encyclopedia, 1998, volume 6 Hart, John.   "Acid Rain," Encarta Deluxe, 2001. Meyer, B. "Sulfuric Acid," World Book Encyclopedia, 1998, volume 18 pages 997-998 Rose, Emily. "Base," World Book Encyclopedia, 1998, volume 2, page 123 Rose, Emily. "Acid," World Book Encyclopedia, 1998, volume 1, pages 26-27 Rock, Peter. "pH," World Book Encyclopedia, 1998, volume 15, page 353 Singer, Walter. "Aquatic Plants," Encyclopedia Americana, 1999, volume 2, page 135  Young, J. A. "Elodea," Encyclopedia Americana, 1999, volume 10 page 259 Back to Top

I would like to thank the following people for their contributions in making my science project possible.

_ My father, Alan, who helped my to set up the solutions and trials for my experiment.
_ My mother, Brooke, who helped my pay for my experiment and display.
_ My neighbors, Matt and Candy Thompson, who inspired my to work on this experiment.
_ Mr. Newkirk, Mrs. Pasckavale, and Mrs. Cooley for helping me to format the procedures, and grammar of this journal, and Mrs. Paskavale for taking a special picture of my buddies and I. 
_ Also my friedns Lacey T., Tiera G., and Vannessa W.  for helping me with all my mistakes.
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