Nitrogen Absorption by Water Hyacinths and Salvinia

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Nitrogen Absorption by Water Hyacinths and
Salvinia
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Abstract

• Water Hyacinth and Salvinia are buoyant plants
  that live in water and are sustained via nutrient
  absorption from sub aquatic root systems
• My hypothesis was that these plants would
  decrease nitrate concentrations in water
• Nitrates, caused by human and animal waste
  products, are a common water pollutant

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Water Hyacinths are already being used as a
natural means to purify sewage
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Method

• Ten habitats were made five per plant
• Potassium Nitrate was added in one-fourth
  decreasing increments using molals
• The fifth container acted as a control
• Deionized water was used to eliminate other
  nutrients and minerals
• Nitrate levels were determined berfore plant
  addition and one week after addition in parts per
  million

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Method

• In each of the experiments the lowest Nitrate
  concentration of the experiment before it was
  divided in fourths to give the new lower
  concentrations for the next test group
• Salvinia use was discontinued after the second
  experiment
• For the remainder of the research five more
  Hyacinths replaced the Salvinia and the Nitrate
  level for these was lowered

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Experiment One

• All of the plants except for the control groups
  died by the end of experiment one
• These concentrations were high and this was expect

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Death of PlantsExperiment 2
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Nitrate Levels Experiment One
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Nitrate Levels Experiment Two
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Nitrate Levels Experiment Three
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Nitrate Levels Experiment Four
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Results

• In Experiments one and two the nitrogen content
  was not decreased enough for my test kit to
  determine nitrate depletion
• Experiments three and four exhibit the ability of
  the Hyacinths to decrease nitrates in water
• The plant was most efficient between .00095
  moles/liter and .0012 moles/liter that is between
  0 and 10 parts per million

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Conclusions

• Hyacinths in an environment of nitrates and
  potassium only do efficiently remove nitrates at
  low molar concentrations
• However, the plant may better eliminate nitrates
  in the presence of other nutrients and in
  environments less stressful than those found in
  the laboratory