Effect of acid rain on algae
The materials required for this science fair project:
- 15 ml of spirogyra algae
- 15 ml of green algae
- 15 ml of red algae
- Check with an aquarium store, if you do not have easy access to natural habitats
- 9 beakers
- 1 bottle of sulfuric acid
- 1800ml of distilled water
- 1 measuring cylinder
- Several pieces of pH paper
- 1 black marker pen
1. For this science fair project, the independent variable is the acidity of the water used for the experiment (pH 5.0, 6.0 and 7.0) and the type of algae – spirogyra, green algae and red algae. The dependent variable is how the algae responds and how well it thrives in the acidic solution. This is determined by observing the algae over a period of time. The constants (control variables) are the amount of water used, the amount of sunlight and the type of algae used.
2. The 9 beakers are separated into 3 groups and labeled as “spirogyra”, “green algae” and “red algae”. The beakers are also labeled as “pH5”,” pH6” or “pH7” and these markings are made beside the names of the algae.
3. Each of the beakers are filled with 200ml of distilled water. The water in the beakers marked “pH 7” is tested with pH paper to verify that it is pH neutral. Sulfuric acid is added to the beakers marked “pH 6” and “pH 5” until the required level of acidity is obtained. The pH levels in each of these beakers is verified using the pH paper. Refer to a pH chart to ascertain the acidity level of the water, given the color that appears on the pH paper.
4. Each type of algae is separated into 3 portions and placed inside (follow the markings on the beakers). The beakers are observed after 5 days to determine if the algae are alive or dead. The observations are recorded in the table given below.
Basic safety requirements, Use gloves and safety goggles/masks when handling the sulphuric acid.