Dissolved Oxygen Levels in Streams with Water Mixtures

Abstract

With sewage running through many streams in today’s environment, it is important to see what is affecting plant/algae life. We tested phosphate and nitrogen to get a better understanding if either of them affects these plants and algae. We tested these items by using a Vernier Optical DO Probe to determine the dissolved oxygen levels in samples of water (clean water, clean water with Phosphate, clean water with Nitrogen, and clean water with Nitrogen and Phosphate) at the beginning and ending of a two week span. After conducting this test, we found that the clean water with Phosphate had the most oxygen at the beginning, but the least at the end. However, all of the samples gained a considerable amount of oxygen over the experiment. The least gained oxygen was brought about by the clean oxygen and Phosphate gaining about .7 mg/L of oxygen, and the clean water with the most gained a total of 1.4 mg/L oxygen. These results meant clean water gains the most oxygen (in mg/L) over a long period of time, being the most sought after for plant and algae life. This means that sewage runoff and the adding of Nitrogen and Phosphate to our water supplies hurt our plant and algae life as well as our environment.