Observações sobre o fitoplâncton de lagoas de estabilização e avaliação de remoção algal via flotação com ar dissolvido

• Ano de defesa: 2013
• Autor(a) principal: Oliveira, Expedito Rômulo Amado de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Saneamento; Lagoas de estabilização; Alga de água doce; Bactérias
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/5653

The composition, weekly change, and evaluation of removal of phytoplankton biomass by Dissolved Air Flotation with a system of stabilization ponds Station Wastewater Treatment Aquiraz - EC was studied during the period from May to December 2011. Analyzing data removal efficiency of solids, COD, BOD, Turbidity, Coliform and density of organisms. Qualitatively the phytoplankton is composed of 36 specific taxa spread over 14 green algae, 11 euglenoids, 7 cyanobacteria, 2 bacilariofíceas, 1 criptofícea and only one clamidofícea. Although the number of species of green algae, the highlight densidadade and frequency was Planktotrhix agardhii, species known as producing toxins, dominating throughout the study period. This species has been supplanted in a very few weeks a coccoid green algae. Decrease occurred in the number of classes among the ponds along the survey reduction and worsening of species richness among lakes, culminating with the concentration of more than 90% of the composition of organisms belonging to a single species of cyanobacteria. Cyanophyceae were found with averages of 7.9 x105 to 1.6 x 106 org./mL. The results are worrying regarding the toxic potential of the dominant species and is thrown into the River Pacoti plus ponds behave like stock hormogon and replication of these organisms to the environment. In tests of removal, effluent Maturation Pond had 5.7 x 104 ind / mL, 132 NTU turbidity, 4,8 x103 NMP E. coli. The flotation tests with dissolved air show to be promising. After flotation, fell to 291,4 org/L, 2.7 NTU, 102 NMP E. Coli/100mL. The lowest efficiency of BOD, reaching averages of 73%. The COD was removed at 80%. Flotation had to be helped by coagulants. Was removed 98% of the phytoplanktonic organisms, 98.8% of fecal and 98% turbidity. E. coli was reduced by two logarithmic units, resulting in <600 NMP/100mL. The low bacterial concentration allows state after simple disinfection, reuse for irrigation, urban car washing and other uses of human contact restricted.