1. Phosphorous Remediation of Various Water Samples With Duckweed Wilnely Rivera, Amber Stangroom, Richard Tia, and Mark Troutt Introduction This experiment answered two questions; What are the phosphorus levels of various water samples? and How effective is duckweed in the remediation of these samples? These questions were asked so that we could determine not only how effective duckweed is at removing phosphorus but also to see how great a need there is for phosphorus remediation. The following results, we believe, accurately answers the first of these questions. The following duckweed results may not be entirely accurate and cannot be taken fully at face value. Figure 1. Graph of change in absorbance. Procedure Collect different water samples (pond, well, tap, etc.) Measure absorbance level to figure out phosphorus concentration Add duckweed to samples Wait five days for remediation to occur Filter out the duckweed from the water Measure absorbance again References "Application of Duckweed in Treating Municipal Wastewater." Foundation for Water Research. Apr. 1993.21Dec.2007. Results No duckweed Duckweed Conclusions Only the pond water sample showed a significant decrease in phosphorous levels. All of the other samples showed an increase in the amount of phosphorous. There could be several reasons for this. One explanation is that the caps on the BOD bottles were too tight and no air could get in, disrupting normal gas exchange. That would cause the duckweed to die and release phosphorous. Another reason why only the pond water showed positive results could be because the duckweed was raised in the pond water and became adapted to its specific oxygen and nutrient levels. This could cause it to flourish in the pond sample and die in the tap and well water. Also, some human error could have caused the results. A pond water sample had to be thrown out because the device used to filter out the duckweed had a backup of tap water which mixed with the sample. The same thing could have happened to our other samples without being noticed. Based on the research by other people on this subject; the results after the experiment disagreed with that of the other people, who performed a similar experiment using duckweed. In the experiment, the phosphorous levels of the different water samples were raised after the duckweed was left in them for a few days, while in other experiments the phosphorous levels were lowered. Figure 3. Duckweed, “The Remediator”. When testing the phosphorous levels of various water When testing the phosphorous levels of various water sources we were quite surprised with the results we got. For our experiment we used three main water sources which were tap,well, and pond water. Out of the water samples tap had the highest phosphorous levels. That was a shock, because in most places tap water is the most fasted way to get water. Thats a problem because we need to take better care of our water sources. We performed a experiment in which we added duckweed to the samples. The results we got from the experiment weren't that great because intead of decreasing the phosphorous level, the duckweed actually increased the phosphorous levels. The only good result we had was from the pond water. it decreased the phosphorous levels from 0.179 to 0.042.