Too Much of a Bad Thing Can Be Good: The Introduction of Yeast Into Water Polluted by Fertilizer

Abstract

An experiment was conducted by Alan D. Tappin and others on the effect of removing Atrazine from river waters by indigenous organisms. In that experiment they added Atrazine, a common component in herbicides, to a water source with the idea that it may reduce contaminants within that source when combined with a decomposer. The experiment involving Atrazine noted that concentrations of contaminants decreased by 11% over the course of 21 days. We hoped to mimic these results with alternate chemicals. Our experiments was designed around adding a decomposer (yeast) and an extra nitrogen-phosphorous source (fertilizer) to the water sample, and then observe the changes in dissolved oxygen content. With the nitrogen based fertilizer injected into the water source as well as the augmentation of a decomposer, we predict that our results will be similar to that of the aforementioned experiment. Our first trials with both high and low concentrations of yeast and fertilizer elucidated that the water sample had degraded in quality through the addition of the two nutrients (Original Dissolved Oxygen: 9.12 mg/L). Similarly, by the fourth week of the experiment, the quality of the water sample had significantly decreased, and contended our original hypothesis (W4 Dissolved Oxygen Avg: 8.55 mg/L), suggesting that the addition of the two opposing nutrients did not aid in maintaining, or improving water quality over time nor did they alter the dissolved oxygen concentrations within the samples.