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EUTROPHICATION MEDIATES COMPLEX INTERACTIONS BETWEEN CYANOBACTERIA AND DIATOMS THAT INFLUENCE TASTE AND ODOR EVENTS IN A DRINKING WATER RESERVOIR (E)

Taste and odor compounds, such as geosmin and 2-methylisborneol (MIB), are secondary metabolites that cause drinking water to taste earthy or musty. These compounds can be detected at minute concentrations that can promote consumer mistrust. Removal of these compounds is costly and generally unreliable, therefore it is imperative for water resource managers to understand the causes of these events to minimize off-flavor production at the watershed level. We conducted two limnocorral experiments in a drinking water reservoir to determine the effects of different treatments on phytoplankton community structure and MIB and geosmin production. In the first experiment conducted during the fall, we assessed the impact of a range of nitrogen concentrations and nitrogen-to-phosphorus ratios. In the second experiment conducted during the summer, we tested the effects of nitrogen and phosphorus fertilization and vertical mixing. Fertilization with both nitrogen and phosphorus (but not added separately) promoted MIB after several weeks in both experiments. Interestingly, MIB dynamics were consistent with a gradual increase in diatoms in both experiments. In contrast, geosmin, which was only measured in the summer experiment, responded quickly to nitrogen and phosphorus fertilization similar to cyanobacteria. Our findings show that nitrogen and phosphorus additions affect the production of taste and odor compounds. However, the association of MIB and geosmin production to cyanobacteria or diatoms is complicated and influenced by season, further complicating the management of taste and odor compounds in drinking water reservoirs.

http://www.wilsonlab.com/

Authors

Fernandez, E. G., Auburn University, USA, edna.fernandez@auburn.edu

Olsen, B. K., Auburn University, USA, bko0003@tigermail.auburn.edu

Chislock, M. F., Purdue University, USA, mchisloc@purdue.edu

Rebelein, A., University of Erlangen-Nuremberg, Germany, anja@rebeleinnet.de

Thornton, W., Opelika Utilities, USA, wthornton@owwb.com

Hilyer, D., Opelika Utilities, USA, dhilyer@owwb.com

Wilson, A. E., Auburn University, USA, wilson@auburn.edu

Details

Oral presentation

Session #:021
Date: 03/01/2017
Time: 17:15
Location: 323 B

Presentation is given by student: Yes