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PT13 Aquatic Ecotoxicology I
(PT198) Evaluation of the Acute and Chronic Effect of Effluent ECF on the Reproduction of Daphnia magna.
Baptista, I1, Soares, C1, 1 Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
ABSTRACT- The objective of this work was to evaluate acute and chronic toxicity of treated and non-treated ECF (Elementar Chlorine Free) effluent performed on Daphnia magna. Three types of reproduction 21-day tests were carried out with Scenedesmus subspicatus neonates (< 24-hour-olds). Tests were carried out in replicate using 100 ml of test solution in flasks containing five individuals, exposed to four different concentrations (12,5%, 25%, 50% and 100%). A control for each test was performed. In the first assay, the organisms were submitted to different effluent concentrations and fed with standard Scenedesmus subspicatus culture. In the second assay, the organisms were submitted to the same concentration range as the effluent and fed with Scenedesmus subspicatus, grown in the same concentration range of the effluent. In a third assay, the organisms were incubated in a standard culture solution and fed with Scenedesmus subspicatus, grown in the same concentration range. The results of the first assay demonstrated that the daphnides submitted to the both effluents, presented a higher reproduction ratio compared to the controls, being that this ratio was higher in the non-treated effluent. In both effluents the 25% concentration presented the highest neonates ratio, and the 100% concentration presented the lowest. In the second assay, all the tested concentrations presented a lower ratio as compared to the control, being the 25% concentration the lowest. In the third assay, only the 25% and 100% concentrations presented a lower ratio than that of the control, being that the lowest was in the 100% concentration and the highest was in the 50% concentration. Although not presenting acute toxic effects on the exposed organisms, the results obtained showed that the presence of toxic chemical components in the effluent and those bioacumulated by the algae, potencialized the effect of toxicity on the Daphnia magna reproduction ratio.
Key words: pulp and paper, reproduction ratio, Daphnia magna , bioaccumulation
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