Taxonomia, estrutura e dinâmica do fitoplâncton e do zooplâncton em um sistema piloto de tratamento de esgoto sanitário em lagoas de polimento

• Ano de defesa: 2011
• Autor(a) principal: Magalhães, Adriana Barbosa Sales de
• Orientador(a): Otoni, Wagner Campos
• Banca de defesa: Cecon, Paulo Roberto , Nascimento, Antonio Galvão do , Jardim, Fernando Antônio , Bastos, Rafael Kopschitz Xavier
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Botânica
• Departamento: Botânica estrutural; Ecologia e Sistemática
• País: BR
• Palavras-chave em Português: Taxonomia; Fitoplâncton; Zooplâncton; Tratamento de esgoto sanitário; Lagoas de polimento
• Palavras-chave em Inglês: Taxonomy; Phytoplankton; Zooplankton; Sewage treatment plant; Polishing ponds
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BOTANICA
• Link de acesso: http://locus.ufv.br/handle/123456789/382

Even though the microalgae and cyanobacteria has been proven as an important part of the sewage treatment, there are few available studies about taxonomy of those organisms in sewage treatment plants. The purpose of the current study is to provide the taxonomic information of the phytoplankton in a pilot sewage treatment plant, to evaluate the phytoplankton community structure and the effectiveness of a sewage treatment system focusing the phytoplankton community. The system is a set of reactor UASB + biofilter aerated and submerged (in real scale), followed by four sequential pounds (pilot scale). The study were developed using analytical data of samples from four sequential pounds between February and June of 2009. The samples were collected with plankton net (pore size 20 μm) and divided into two samples. The former subdivided sample were treated with formaldehyde 4% and the other part of the sample were kept alive to further observation of the morphological characteristics, because of essential role to its identification. The analysis were performed in optical microscope and the taxa were identified and described including morphological and metrical parameters of vegetative and reproductive life of the population sampled. Those analysis have provided information about the morphological and metric variation of the each unit evaluated. We have used identification keys available in specialized papers and books to achieve the taxonomic classification. The phytoplankton community were analyzed by its main attributes: abundant and dominant species, diversity, species evenness, number of taxa and population density. The samples for analysis zooplankton were collected with plankton net (pore size 68 μm) and packed in glass containers and preserved in formaldehyde 4%. For taxonomic analysis and quantification of organisms used a light microscope and a stereoscopic microscope with increased up to 1000 times. Taxonomic analysis was done at the level of large groups, with the use of literature specific to each group. We have analyzed the following parameters: visibility, temperature, dissolved oxygen, pH, alkalinity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen Kjeldahl (TN), ammoniacal nitrogen, nitrate (NO3), total phosphate (TP), orthophosphate, total suspense solids (TSS), chlorophyll a, precipitation and air temperature. We have registered 103 taxa among seven classes: Chlorophyceae (53), Euglenophyceae (21), Cyanobacteria (18), Cryptophyceae (6), Zygnemaphyceae (2), Chrysophyceae (2) and Dinophyceae (1). Based in qualitative paramers the predominat class were Chlorophyceae, followed by Euglenophyceae, Cyanophyceae and Cryptophyceae. The classes Zygnemaphyceae, Dinophyceae and Chrysophyceae were not well disseminated. The L3 has achieved large phytoplankton composition with 91 identified taxa, followed by L2 (87), L4 (81) and L1 (73). In the four pounds evaluated, the class Chlorophyceae presented the large number of species (27), with the specie Chlorella vulgaris representing 50% of the samples. In the class Euglenophyceae there was a decrease in the density from the L1 to L4. The species Menoidium gracile and Phacus dangeardii were found in large amounts in all of the pounds. As for dominance, we have registered dominant organisms only in the classes Cyanophyceae (1) and Chlorophyceae (5). In the class Cyanophyceae only the specie Aphanocapsa delicatissima and in the class Chlorophyceae the specie Chlorella vulgaris has dominate almost all the evaluated time with bigger impact in the L1. Other than Chlorella vulgaris, all species evaluated of the genus Scenedesmus (Scenedesmus ellipticus, Scenedesmus dimorphus, Scenedesmus acuminatus e Scenedesmus acutus) were dominants. The diversity increased from the L1 in direction to L2 and we have seen more diversity when less dominance were present and vice versa. The zooplankton were represented by Rotifers, Copepod and Cladocera in low density, from 604 org L-1 in the L4 to 2.509 org L-1 in the L2. Along the evaluated time we could see efficiency on the decrease of BOD, TN, NH3 and chlorophyll a. However, there were no significant decrease of the COD, TP, NO3 and orthophosphate contents.