Avaliação ecotoxicológica de metais/metalóides e interferentes endócrinos em frações de substâncias húmicas de diferentes tamanhos moleculares
| Ano de defesa: | 2015 |
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| Autor(a) principal: | |
| Orientador(a): | |
| Banca de defesa: | |
| Tipo de documento: | Dissertação |
| Tipo de acesso: | Acesso aberto |
| Idioma: | por |
| Instituição de defesa: |
Universidade Estadual Paulista (Unesp)
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| Programa de Pós-Graduação: |
Não Informado pela instituição
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| Departamento: |
Não Informado pela instituição
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| País: |
Não Informado pela instituição
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| Palavras-chave em Português: | |
| Link de acesso: | http://hdl.handle.net/11449/124025 http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/15-05-2014/000830249.pdf |
Resumo: | At this work, toxicity tests using metalloid arsenic, metal cobalt and emerging contaminant 17β-estradiol were studied in the presence and absence of aquatic humic substances (AHS) and its fractions of different molecular sizes (<5, 5-10; 10-30; 30-100 and > 100 kDa), using the Ceriodaphnia dubia and Pseudokirchneriella subcapitata organisms. The tests using C. dubia, influence of AHS contact arsenic metal in toxicity reducing by statistical analysis AHS and the different fractions showed different behavior in each other, reducing toxicity fractions of larger molecular size, in decreasing order of toxicity: F1 = F2 <F3 <F4 = F5. In regard to cobalt despite, the toxicity reduction was not observed the influence of the molecular size of AHS in toxicity between fractions using a concentration of 50 μgL-1, where fraction of molecular size showed the following order of toxicity: F5 F4 = <F3 <F2 <F1. Assays using P. subcapitata shown that presence of AHS even alone, cause an inhibition in the growth of the organism in almost all concentrations of the three substances studied, related composition, bonds present in the extract SHA and interactions between the surface seaweed and organic matter. Thus, combined with the test chemical toxicity studies show that the humic substances was much different behavior with regard to the test organism and which is interacting substance, which may act either as or as potentiators of minimizing toxic effects in different organisms |