The Effects of Acid Rain on Algal

GrowthAlex Zapinski

Pittsburgh Central Catholic

PJAS 2015

Grade 9

Acid Rain Contains high amounts of nitric and sulfuric

acids Created by emissions of sulfur dioxide and

nitrogen oxides. Emissions come from both natural and man

made factors Can be deposited onto the earth in two

forms: dry and wet deposition

AlgaeLarge and diverse group of

eukaryotic organisms, typically autotrophs

Base of all aquatic food chainsUsed as a bio-indicator for aquatic

ecosystems

Euglena gracilis Generally cylindrical in shape with many

flagella Common algal like protist Partial heterotroph- endocytosis and

photosynthesis Capable of surviving in both salt and

freshwater ecosystems A common lab subject

SpectrophotometryMeasures the amount of light that

passes through a medium at a set wavelength

Commonly used in physics, chemistry, biochemistry, material science, and molecular biology

Past studies Some limiting factors such as sulfuric acid can

cause algal blooms

Algal blooms can lead to the deoxygenization of the pond and death of other aquatic life

High concentrations of sulfuric acid have been shown to be a hindrance to the growth of algae

Interaction of Components Algae in nature is commonly affected by

acid rain, which can have devastating effects on the surrounding environment

The sulfuric acid affects the growth of the euglena

The spectrophotometer is used to measure the growth of the algae

PurposeTo determine if sulfuric acid has

significant effects on the growth of Euglena gracilis.

Hypothesis Null hypothesis- the sulfuric acid will not

have significant effects on the growth of Euglena gracilis

Alternative hypothesis- the sulfuric acid will have significant effects on the growth of Euglena gracilis

Materials Euglena gracilis 35 test tubes (13 x 100 mm culture tubes

borosilicate) Micro-pipettes Micro-pipette tips Spectrophotometer Test tube racks 0.1 M sulfuric acid Spring water Soil water

Procedures1. Racks with tubes were set up on a desk 46 cm away from a lamp.

2. The temperature of the room was set to 20-21 degrees Celsius.

3. The following ingredients were added to the tubes to create the following experimental concentrations of sulfuric acid.

Tube concentrations (mL)

Molarity

10-2 10-3 10-4

10-3 Substock

10-5

10-3 Substock

Control0

SulfuricAcid

0.5 0.05 0.5 0.05 0

Euglena 1 1 1 1 1

Soil Water

1 1 1 1 1

Spring Water

2.5 2.95 2.5 2.95 3

TotalVolume

5 5 5 5 5

4. The top of each tube was covered with wax paper and mixed by inversion.

5. The absorbance was taken at 430nm using a spectrophotometer.

6. Absorbance readings were taken every two days for 14 days.

Procedures (cont.)

Anova: Single Factor Analysis of data that compares variation

within groups to variation between the groups

Alpha: 0.05 If the p-value is below the alpha, then the

effects are significant

Day 1: 0.3795P-values:

430

nm Day 3: 10-13

Day 7: 10-11

Day 13: 10-22

Dunnett's Test Compares experimental groups back to the

control Determines which experimental groups

produced significant variation If T value > T-crit then the results were

significant

T-crit= 2.689

10-2

Sulfuric Acid

10-3 10-4 10-5

Day 3T-value

12 5.1 .632 1.288

Significance Significant Significant Not Sig. Not Sig.

Day 7T-value

13.748 4.208 0.705 2.114

Significance Significant Significant Not Sig. Not Sig.

Day 13T-value

29.2599 9.592 9.11 4.69

Significance Significant Significant Significant Significant

Conclusion Null hypothesis would be rejected for the

concentrations of 10-2 and 10-3

Null hypothesis would be accepted for the concentrations of 10-4 and 10-5 except for day 13

Limitations and ExtensionsLimitations- Health of Euglena? Controlled temperature

Extensions- Use more species of algae Use more replicates Use more concentrations of sulfuric acid Use concentrations of nitric acid The synergistic effects of sulfuric acid and

other chemicals

Works cited http://www.epa.gov/acidrain/index.html http://www.physics.ohio-state.edu/~kagan/

phy367/P367_articles/AcidRain/effects-on-lakes.html

http://www.fcps.edu/islandcreekes/ecology/euglena.htm

http://www.chemspider.com/Chemical-Structure.1086.html

Mark Krotec, PTEI

Anova: Single Factor

SUMMARYGroups CountSum Average Variance

1 7 1.3130.187571 6.7E-052 7 1.8030.257571 0.0001193 7 1.5230.217571 0.0002374 7 1.3390.191286 8.36E-055 7 1.26 0.18 9.87E-05

ANOVASource of Variation SS df MS F P-value F critBetween Groups 0.028157 4 0.00703958.16652 1.05E-13 2.689628Within Groups 0.003631 30 0.000121

Total 0.031788 34  

Anova: Single Factor

SUMMARYGroups CountSum AverageVariance1 7 1.3130.187571 6.7E-05

2 7 1.8030.2575710.0001193 7 1.5230.2175710.0002374 7 1.3390.191286 8.36E-055 7 1.26 0.18 9.87E-05

ANOVA

Source of Variation SS dfMS F P-value F critBetween Groups 0.028157 40.007039 58.16652 1.05E-132.689628Within Groups 0.003631 300.000121Total 0.031788 34

Anova: Single Factor

SUMMARYGroups CountSum AverageVariance1 7 1.1760.1680.000108

2 7 1.7390.2484290.0003863 7 1.34 0.1914290.0003014 7 1.1070.158143 7.35E-055 7 1.0570.1510.000108

ANOVA

Source of Variation SS dfMS F P-value F critBetween Groups 0.043526 40.010882 55.70477 1.85E-132.689628Within Groups 0.00586 300.000195Total 0.049386 34

Anova: Single Factor

SUMMARYGroups CountSum AverageVariance2 7 2.0930.2996.97E-05

3 7 1.1620.1660.000938

4 7 1.0490.1498570.0001675 7 0.9130.130429 7.86E-05 0 0 #DIV/0! #DIV/0!

ANOVA

Source of Variation SS dfMS F P-value F critBetween Groups 0.122942 40.030735 93.99736 6.64E-142.795539Within Groups 0.007521 230.000327Total 0.130462 27