In a world where pollution is a major problem, scientists are looking for ways to improve the quality of our air using plants. Plants take in carbon dioxide during photosynthesis and produce oxygen, but plants may also be able to absorb other pollutants including chemicals like trichloroethylene and benzene. Make sure that all air-quality projects involving chemicals occur in a controlled environment that cannot leak out into the environment. Ensure that proper approval is received before working with any dangerous chemicals.
For this project you will need a type of air pollutant and several house plants to test in a closed environment. You will also require a device that detects the levels of that particular chemical. Some examples of chemicals that would work are benzene, formaldehyde and carbon monoxide. This project tests how well plants remove the chemical from the air through absorption and the survival rate of the plants. A few plants that tend to absorb these chemicals well are the marginita, the pot mum and the Chinese evergreen. Test the plants over the course of a couple of weeks, watering and feeding them as needed, and record your results.
This project is similar to the experiment from section 1. This experiment differs by using three plants of the same species and at least three types of air pollutant but still requires a closed environment and a device that detects the levels of the three pollutants. Depending on the chemicals you use, different detection methods can be used. For example, dosimeter tubes can detect levels of formaldehyde in the air. Create a hypothesis about which chemical the house plant you choose will absorb the most effectively. Place the plant into the several controlled environments and release the chemicals into the air near each plant. Further variation can be added by using different levels of each chemical as well. Make observations and record your results.
There are several harmful chemicals released into the air during smoking and you can detect which plant is the most effective in absorbing it. Using a controlled environment and a device to measure the chemical levels of cigarette smoke, have an adult light a cigarette in each environment and measure the amount of chemicals released in each environment. Test at least three different plants and determine which plant has the highest percentage of absorbed chemicals. This experiment is especially useful if you already live in a house with smokers.
Oxygen, Carbon Dioxide and Humidity
Some indicators as to how well a plant cleans the air are the levels of oxygen, carbon dioxide and humidity in the air. Theoretically, the plant that is most effective on air quality would reduce carbon dioxide, raise oxygen levels and add humidity. This experiment does not require as controlled an environment as the chemical experiments, but you will need a device (or several devices) that detects oxygen, carbon dioxide and humidity levels. Test several plants against each other in separate rooms and see which one has the most positive percentage change among them.