Oh, KNO₃! Effects of Potassium Nitrate on Algal Growth in Water

Abstract

As society advances further, its need for energy, and in turn fossil fuels, will increase. However, these fossil fuels are detrimental to the environment and the air that we breathe. Research into biofuels is an important step into the future of energy. Because some microalgae species are very rich in oil, with levels exceeding 80% of the dry weight, it can act as a viable alternative energy source to these nonrenewable resources (Chisti 2008). Because the overall biomass is so important to biofuel production, an important factor in making algal biofuel plausible is to grow as much organic material as possible. We studied the effect of potassium nitrate (KNO₃) on the growth rate of Chlorella by comparing three experimental groups with varying levels of KNO₃ to a control group. We measured the initial and final cell densities after a week, and repeated the experiment to see if the results were consistent. KNO₃ contains nutrients that are beneficial to plant growth so we hypothesized that as we add more KNO₃ added to an algal inoculated solution, there would be increased growth and cell density.