1. Selection of Biological Methods for Industrial Effluents Assessments Rubinger. Carla Ferreira 1 , Leão. Mônica Maria Diniz, Paulinyi. Helene Maria Universidade Federal de Minas Gerais Departamento de Engenharia Sanitária e Ambiental Programa de Pós graduação em Saneamento, Meio Ambiente e Recursos Hídricos Belo Horizonte – Minas Gerais, Brasil. E-mail: carlarubinger@ufmg.br
2.
3.
4. GOALS This study aimed to identify existing biological methods, bioassays of acute and chronic toxicity, seeking their comparison and their applicability to the assessment of quality of treatment applied to industrial effluents and to understand its advantages and limitations.
5. Therefore we performed a survey of the main methods of toxicity tests used in the analysis of industrial effluents. Identifying existing bioassays for the evaluation of acute and chronic toxicity of industrial wastewater, so this has led to comparisons between the main methods used for the analysis of chronic toxicity of effluent from its applicability, contributing to the compilation of data for environmental monitoring. RESULTS
6. Biological methods or bioassays are tests that use living organisms to produce information on the development and changes, the effect of acute or chronic condition that a particular chemical may exert on living matter. BIOLOGICAL METHODS
7.
8.
9. ECOTOXICOLOGICAL TESTS Toxicity tests to assess the effects of test species, are the exposure of aquatic organisms representative of the environment to various concentrations of one or more substances or environmental factors, for a certain period of time. These tests are called bioassays or biological assays.
26. Comparison between the test methods most commonly used in toxicological evaluation of industrial effluents. Test – organism Type Test duration Variable response Expression results Unicellular Green Algae Acute 72h Specific growth rate of average ECNO Microcrustacian Daphnia sp Acute 48h Mobility (ability nadatória) in 24h and 48h EC50 Acute 48h Immobility of 50% at the end of 48 h EC50 Chronic 21 days Number of offspring, mortality among the parental ECNO, Cex(50, 20, 10%) Microcrustacian Ceriodaphnia SP Chronic 7 days Paternogenica number of offspring, survival of adult females ECNO Phish Acute 96h 100% mortality of the lowest effective concentration LC50 Chronic 7 - 10days Appearance and abnormal LC50 Chronic 14 - 28days Mortality and abnormal behavior and appearance ECNO Chronic 10 – 14days Shock and survival, appearance and abnormal behavior ECNO Bacteria Acute 15min - 2h Decrease bioluminescence ECNO Chronic 2 – 3days Reducing the number of colonies, synthesis of histamine ECNO, Cex(50, 20, 10%) Chronic 30h Reducing the number of colonies, synthesis of β - galactose ECNO, Cex(50, 20, 10%)
27. The methods of biological assays are preventive action procedures, and essential in the estimation of environmental impacts, were used by the authorities. There is no consensus on what would be the best type of test organisms for a particular effluent, but what set of tests should be developed to ensure that the components and byproducts of the degradation of effluents cause the least adverse impact to aquatic biota and consequently to humans. CONCLUSIONS
28. The test methods for toxicity tests are acute or chronic, to an effluent as a whole, they generally follow several standard protocols that include a description of use and culture of the species recommended as test organisms. There is clearly a tendency to use test-organisms which are regulated and standardized over the use of native species. Among the test-organisms as the most frequent search terms are highlighted in the cladoceran Daphnia magna and Ceriodaphnia dubia , followed by the bioluminescent bacterium Vibrio fischeri . No less significant is the use of algae as Pseudokirchneriella subcapitata and fish species such as fathead minnows . CONCLUSIONS
29. Recent studies show changes in standardized test methods as an attempt to increase the degree of security in the face of the same composition of the biota of specific local in which you want to develop particular study. Because they are standardized tests and described internationally longer than the others, the tests using cladocerans as daphnideos are more widespread in research and regulations aimed at examining the toxicity of effluents and chemicals complex. The studies suggest that the toxicological evaluation of aquatic ecosystems by the combined or isolated from an environmental pollutant is recommended that biological testing is done in different trophic levels of the ecosystem. CONCLUSIONS
30. Regarding the response time of a test-organism to the presence or absence of toxicant action of an effluent or chemical compound, it is recommended the use of tests with bacteria, because they generally have a duration of 30 minutes to 2 days only, for sensitivity, the toxicity of industrial effluents and compounds chemical complex there is a definition of pattern or individual species described as more or less sensitive to the action of pollutants. The tests are preferred to chronic acute tests, since they describe situations of damage deeper in the body test and consequently the impact that this toxicant can cause the biocenose that this pollutant is inserted. CONCLUSIONS
31. Thank you all for the attention. Rubinger. Carla F. 1 . Universidade Federal de Minas Gerais Departamento de Engenharia Sanitária e Ambiental Programa de Pós graduação em Saneamento, Meio Ambiente e Recursos Hídricos Belo Horizonte – Minas Gerais, Brasil. E-mail: carlarubinger@ufmg.br