PM05 Aquatic Vertebrate/Invertebrate Toxicology
Exhibit Hall
8:00 AM - Monday, 10 November 2003
(PM096) Dose-Response of Freshwater Rotifers to an Advanced Oxidation Process of Hydrogen Peroxide and Ultraviolet Light.
TenEyck, M1, Balcer, M1, 1 University of Wisconsin-Superior, Superior, WI, USA
ABSTRACT- During the past six years , treatment alternatives such as ozone, ultraviolet radiation, filtration, heat, chemical biocides, and deoxygenation have matured to the point of testing their effectiveness of a potential use of blocking invasive aquatic species and effects on native populations upon discharge into an environment. This system will involve the introduction of hydrogen peroxide(H2O2) to aqueous solutions of filtered Lake Superior Water, filtered Duluth-Superior Harbor water, and laboratory water, followed by UV-C irradiation (254 nm). The aqueous matrix will also be augmented with dissolved oxygen and magnesium oxide. Other aqueous constituents or parameters that may influence process performance will include carbonate alkalinity. In this system, it is believed inactivation of waterborne organisms (freshwater rotifers) can be accomplished photochemically, through the action of radicals, oxidants, or a combination of these systems attributes. The following experiments will examine the influence of water quality on the lifetime of intermediate active oxygen species of H2O2 degradation, residual toxicity effects of H2O2 and intermediate radicals to Ceriodaphnia dubia, and the immediate toxicity effects of the exposed media to the freshwater rotifer species Philodina and Brachionus calyciflorus. Rotifers (n=150) were added to designated treatments (a combination of H2O2 and MgO) and exposed to appropriate UV light levels. Exposed media was transferred into a 150 mL Erlenmeyer flask and aerated. Each experimental flask was fed 250 uL of Selenastrum algae and 250 uL of Yeast- Trout Chow-Cereal Leaves. Aliquots were removed at 24 and 168 h post exposure for Philodina population examination. Aliquots were removed at 24 and 72 h post exposure for B. calyciflorus. Preliminary results indicate a significant (p<0.05) reduction in the Philodina and B. calyciflorus at the appropriate time periods. The exposed media was held for 24 h to check for peroxide degradation, C dubia (n = 40) were exposed to the media and survival was checked 48 h post exposure. Complete mortality occurred.
Key words: rotifers, advanced oxidzation process, ultraviolet light, invasive species