The Effects of Acid Rain on Algal Growth

Alex 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

Algae ! Large and diverse group of eukaryotic

organisms, typically autotrophs ! Base of all aquatic food chains ! Used 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

Spectrophotometry ! Measures 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

Purpose ! To 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

Procedures 1. 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 Control 0

Sulfuric Acid

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

Total Volume

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: 0.3795 P-values:

430n

m 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 3 T-value

12 5.1 .632 1.288

Significance Significant Significant Not Sig. Not Sig.

Day 7 T-value

13.748 4.208 0.705 2.114

Significance Significant Significant Not Sig. Not Sig.

Day 13 T-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 Extensions ! Limitations- ! 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

SUMMARY Groups Count Sum Average Variance 1 7 1.313 0.187571 6.7E-05 2 7 1.803 0.257571 0.000119 3 7 1.523 0.217571 0.000237 4 7 1.339 0.191286 8.36E-05 5 7 1.26 0.18 9.87E-05

ANOVA Source of Variation SS df MS F P-value F crit Between Groups 0.028157 4 0.007039 58.16652

1.05E-13 2.689628 Within Groups 0.003631 30 0.000121

Total 0.031788 34  

Anova: Single Factor SUMMARY Groups Count Sum Average Variance

1 7 1.313 0.187571 6.7E-05 2 7 1.803 0.257571 0.000119 3 7 1.523 0.217571 0.000237 4 7 1.339 0.191286 8.36E-05 5 7 1.26 0.18 9.87E-05 ANOVA Source of Variation SS df MS F P-value

F crit Between Groups 0.028157 4 0.007039

58.16652 1.05E-13 2.689628 Within Groups 0.003631 30 0.000121

Total 0.031788 34

Anova: Single Factor SUMMARY Groups Count Sum Average Variance

1 7 1.176 0.168 0.000108 2 7 1.739 0.248429 0.000386 3 7 1.34 0.191429 0.000301 4 7 1.107 0.158143 7.35E-05 5 7 1.057 0.151 0.000108 ANOVA Source of Variation SS df MS F P-value

F crit Between Groups 0.043526 4 0.010882

55.70477 1.85E-13 2.689628 Within Groups 0.00586 30 0.000195

Total 0.049386 34

Anova: Single Factor SUMMARY Groups Count Sum Average Variance

2 7 2.093 0.299 6.97E-05 3 7 1.162 0.166 0.000938 4 7 1.049 0.149857 0.000167 5 7 0.913 0.130429 7.86E-05 0 0 #DIV/0! #DIV/0! ANOVA Source of Variation SS df MS F P-value

F crit Between Groups 0.122942 4 0.030735

93.99736 6.64E-14 2.795539 Within Groups 0.007521 23 0.000327

Total 0.130462 27