Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro

Detalhes bibliográficos
Autor(a) principal: Torres, Dayana Melo
Data de Publicação: 2011
Tipo de documento: Dissertação
Idioma: por
Título da fonte: Repositório Institucional da UFRN
Texto Completo: https://repositorio.ufrn.br/jspui/handle/123456789/15977
Resumo: Stabilization pond system consisting in more sewage treatment used in Rio Grande do Norte (RN), Brazil, representing about 90% of all systems. Fecal bacteria are removed mainly facultative ponds and in maturation ponds. Many factors influence bacterial decay, such as the levels of pH and DO, temperature, light intensity, HDT and nutrient availability. The bacterial decay rate (Kb) is calculated considering many variables, but the hydraulic regime is a significant influence for microorganisms removal, and the dispersed flow which best characterizes a stabilization pond. However, some authors developed equations for the Kb accordant plug flow and complete mixing. This research study aimed to evaluate the bacterial decay of fecal coliform and Enterococcus sp. in stabilization ponds designed to treat domestic sewage, full-scale, in RN. All systems have assessed pretreatment, a facultative pond (LF) followed by two maturation (LM1 and LM2). The parameters availed were: temperature, pH, DO, BOD5, COD, fecal coliform, Enterococcus sp., Chlorophyll a, total suspended solids, fixed and volatile. In general, there were not significant differences for pH, DO and temperature in the ponds, except for the new systems, since they have low flow and hydraulic loads. The removal of organic matter in the ponds was low, about 70%, and nearly all are overloaded organic and operational problems. The bacterial removals were low, with average 96% for LF for fecal coliform, and 98% for Enterococcus sp.; LM1 were in itself a removal for fecal coliform about 71%, and 81% for Enterococcus sp.; LM2 have efficiency of 69% for fecal coliform, and 68% for Enterococcus sp. The equation proposed by Von Sperling (1999), according to the dispersed flow regime, generated empirical values of Kb more approximate to calculated values of Kb. On average, the calculated Kb to coliforms in the LF was 0.31 d-1, and for both maturation ponds were 0.35 d-1. For Enterococcus sp. the average was 0.40 d-1 for LF, 0.55 d-1 for LM1, and 0.58 d-1 for LM2. These results also showed that the Kb obtained in full-scale systems are smaller than those found in pilot-scale ponds. Moreover, one can say that the equation proposed by Marais (1974), according to the complete-mix regime, overestimates Kb. Actual results of Kb indicated that fecal coliforms are more resistant to adverse conditions present in stabilization ponds than Enterococcus sp., therefore, an indicator of microbiological safety and efficiency. The factors significant interventions in the rate of bacterial decay were concentrations of COD, the organic loading and HDT. The few Kb relationship between pH, DO and temperature were not significant. Finally, we conclude that it s essential to correct operation and maintenance, for not performing these activities is one of the main factors contributing to low rates of bacterial decay.
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spelling Torres, Dayana Melohttp://lattes.cnpq.br/6920200718463532http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4799320A6Andrade Neto, Cícero Onofre deANDRADE NETO, Cícero Onofre deSantos, Hélio Rodrigues doshttp://lattes.cnpq.br/9048384392428073Konig, Annemariehttp://lattes.cnpq.br/1484397481626689Araújo, André Luis Calado2014-12-17T15:03:27Z2012-01-162014-12-17T15:03:27Z2011-06-17TORRES, Dayana Melo. Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro. 2011. 99 f. Dissertação (Mestrado em Saneamento Ambiental; Meio Ambiente; Recursos Hídricos e Hidráulica) - Universidade Federal do Rio Grande do Norte, Natal, 2011.https://repositorio.ufrn.br/jspui/handle/123456789/15977Stabilization pond system consisting in more sewage treatment used in Rio Grande do Norte (RN), Brazil, representing about 90% of all systems. Fecal bacteria are removed mainly facultative ponds and in maturation ponds. Many factors influence bacterial decay, such as the levels of pH and DO, temperature, light intensity, HDT and nutrient availability. The bacterial decay rate (Kb) is calculated considering many variables, but the hydraulic regime is a significant influence for microorganisms removal, and the dispersed flow which best characterizes a stabilization pond. However, some authors developed equations for the Kb accordant plug flow and complete mixing. This research study aimed to evaluate the bacterial decay of fecal coliform and Enterococcus sp. in stabilization ponds designed to treat domestic sewage, full-scale, in RN. All systems have assessed pretreatment, a facultative pond (LF) followed by two maturation (LM1 and LM2). The parameters availed were: temperature, pH, DO, BOD5, COD, fecal coliform, Enterococcus sp., Chlorophyll a, total suspended solids, fixed and volatile. In general, there were not significant differences for pH, DO and temperature in the ponds, except for the new systems, since they have low flow and hydraulic loads. The removal of organic matter in the ponds was low, about 70%, and nearly all are overloaded organic and operational problems. The bacterial removals were low, with average 96% for LF for fecal coliform, and 98% for Enterococcus sp.; LM1 were in itself a removal for fecal coliform about 71%, and 81% for Enterococcus sp.; LM2 have efficiency of 69% for fecal coliform, and 68% for Enterococcus sp. The equation proposed by Von Sperling (1999), according to the dispersed flow regime, generated empirical values of Kb more approximate to calculated values of Kb. On average, the calculated Kb to coliforms in the LF was 0.31 d-1, and for both maturation ponds were 0.35 d-1. For Enterococcus sp. the average was 0.40 d-1 for LF, 0.55 d-1 for LM1, and 0.58 d-1 for LM2. These results also showed that the Kb obtained in full-scale systems are smaller than those found in pilot-scale ponds. Moreover, one can say that the equation proposed by Marais (1974), according to the complete-mix regime, overestimates Kb. Actual results of Kb indicated that fecal coliforms are more resistant to adverse conditions present in stabilization ponds than Enterococcus sp., therefore, an indicator of microbiological safety and efficiency. The factors significant interventions in the rate of bacterial decay were concentrations of COD, the organic loading and HDT. The few Kb relationship between pH, DO and temperature were not significant. Finally, we conclude that it s essential to correct operation and maintenance, for not performing these activities is one of the main factors contributing to low rates of bacterial decay.Lagoas de estabilização consistem no sistema de tratamento de esgotos mais utilizado no Rio Grande do Norte (RN), Brasil, correspondendo a cerca de 90% de todos os sistemas. As bactérias fecais são removidas principalmente nas lagoas facultativas e de maturação. Muitos fatores influenciam no decaimento de bactérias, como: os níveis de pH e OD, temperatura, intensidade luminosa, TDH e disponibilidade de alimento. A taxa de decaimento bacteriano (Kb) é calculada a partir de muitas variáveis, mas o regime hidráulico possui significativa influência na remoção de microorganismos, sendo o de fluxo disperso o que melhor caracteriza uma lagoa de estabilização. Todavia, alguns autores elaboraram equações para o Kb conforme o regime de mistura completa. Essa pesquisa teve como objetivo avaliar o decaimento bacteriano de coliformes termotolerantes e Enterococcus sp. em lagoas de estabilização destinadas ao tratamento de esgotos domésticos, em escala real, no RN. Todos os sistemas avaliados possuem tratamento preliminar, uma lagoa facultativa (LF), seguida de duas de maturação (LM1 e LM2). Os parâmetros avaliados foram: temperatura, pH, OD, DBO5, DQO, coliformes termotolerantes, Enterococcus sp., clorofila a, sólidos em suspensão totais, fixos e voláteis. Não foram identificadas diferenças significativas entre os valores de pH, OD e temperatura nas lagoas, exceto para os sistemas mais novos, já que eles possuem baixas vazões e cargas hidráulicas. A remoção de matéria orgânica nos sistemas de tratamento foi baixa, cerca de 70%, e praticamente todas estão com sobrecarga orgânica e com problemas operacionais. As remoções bacterianas também foram baixas, com média para as LF de 96% para coliformes termotolerantes, e de 98% para Enterococcus sp.; nas LM1 obteve-se remoção para coliformes termotolerantes de 71%, e para Enterococcus sp. de 81%; e, nas LM2 a eficiência foi de 69% para coliformes termotolerantes e de 68% para Enterococcus sp. A equação proposta por Von Sperling (1999), segundo o regime de fluxo disperso, foi a que gerou valores de Kb empíricos mais aproximados dos valores de Kb calculados a partir de dados reais. Em média, o Kb calculado com base nos dados reais para coliformes termotolerantes nas LF foi de 0,31 d-1, e em ambas as lagoas de maturação foram de 0,35 d-1. Para Enterococcus sp. a média nas LF foi de 0,40 d-1, nas LM1 foi igual a 0,55 d-1, e nas LM2 de 0,58 d-1. Esses resultados também demonstraram que os Kb obtidos em sistemas em escala real são menores do que os verificados em lagoas em escala piloto. Além disso, pode-se afirmar que a equação proposta por Marais (1974), segundo o regime de mistura completa, superestima o Kb. Os resultados dos Kb calculados indicaram que os coliformes termotolerantes são mais resistentes às condições adversas presentes em lagoas de estabilização do que os Enterococcus sp., sendo, portanto, um indicador microbiológico mais eficiente e seguro. Os fatores de significativa intervenção na taxa de decaimento bacteriano foram as concentrações de DQO, a carga orgânica e o TDH. As poucas relações existentes entre Kb com pH, OD e temperatura não foram estatisticamente significativas. Por fim, conclui-se que é fundamental a operação e manutenção corretas, pois a não realização dessas atividades consiste em um dos principais fatores que contribuem para as baixas taxas de decaimento bacteriano.Coordenação de Aperfeiçoamento de Pessoal de Nível Superiorapplication/pdfporUniversidade Federal do Rio Grande do NortePrograma de Pós-graduação em Engenharia SanitáriaUFRNBRSaneamento Ambiental; Meio Ambiente; Recursos Hídricos e HidráulicaLagoas de estabilizaçãoDecaimento bacterianoColiformes termotolerantesEnterococcus sp.Stabilization pondsBacterial decayThermotolerant coliformEnterococcus sp.CNPQ::ENGENHARIAS::ENGENHARIA SANITARIADecaimento bacteriano em lagoas de estabilização no Nordeste brasileiroinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRNinstname:Universidade Federal do Rio Grande do Norte (UFRN)instacron:UFRNORIGINALDayanaMT_DISSERT.pdfapplication/pdf5461193https://repositorio.ufrn.br/bitstream/123456789/15977/1/DayanaMT_DISSERT.pdfe14ad35e988326c6b2deb98ea1ef274eMD51TEXTDayanaMT_DISSERT.pdf.txtDayanaMT_DISSERT.pdf.txtExtracted texttext/plain169669https://repositorio.ufrn.br/bitstream/123456789/15977/6/DayanaMT_DISSERT.pdf.txtc8fadaaab3931bd1946d7bfba5d2b06cMD56THUMBNAILDayanaMT_DISSERT.pdf.jpgDayanaMT_DISSERT.pdf.jpgIM Thumbnailimage/jpeg2595https://repositorio.ufrn.br/bitstream/123456789/15977/7/DayanaMT_DISSERT.pdf.jpgb3824faff2159c563e5fdd8558f0bd2fMD57123456789/159772017-11-02 08:50:29.817oai:https://repositorio.ufrn.br:123456789/15977Repositório de PublicaçõesPUBhttp://repositorio.ufrn.br/oai/opendoar:2017-11-02T11:50:29Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN)false
dc.title.por.fl_str_mv Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro
title Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro
spellingShingle Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro
Torres, Dayana Melo
Lagoas de estabilização
Decaimento bacteriano
Coliformes termotolerantes
Enterococcus sp.
Stabilization ponds
Bacterial decay
Thermotolerant coliform
Enterococcus sp.
CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA
title_short Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro
title_full Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro
title_fullStr Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro
title_full_unstemmed Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro
title_sort Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro
author Torres, Dayana Melo
author_facet Torres, Dayana Melo
author_role author
dc.contributor.authorID.por.fl_str_mv
dc.contributor.authorLattes.por.fl_str_mv http://lattes.cnpq.br/6920200718463532
dc.contributor.advisorID.por.fl_str_mv
dc.contributor.advisorLattes.por.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4799320A6
dc.contributor.referees1.pt_BR.fl_str_mv Andrade Neto, Cícero Onofre de
dc.contributor.referees1ID.por.fl_str_mv
dc.contributor.referees1Lattes.por.fl_str_mv ANDRADE NETO, Cícero Onofre de
dc.contributor.referees2.pt_BR.fl_str_mv Santos, Hélio Rodrigues dos
dc.contributor.referees2ID.por.fl_str_mv
dc.contributor.referees2Lattes.por.fl_str_mv http://lattes.cnpq.br/9048384392428073
dc.contributor.referees3.pt_BR.fl_str_mv Konig, Annemarie
dc.contributor.referees3ID.por.fl_str_mv
dc.contributor.referees3Lattes.por.fl_str_mv http://lattes.cnpq.br/1484397481626689
dc.contributor.author.fl_str_mv Torres, Dayana Melo
dc.contributor.advisor1.fl_str_mv Araújo, André Luis Calado
contributor_str_mv Araújo, André Luis Calado
dc.subject.por.fl_str_mv Lagoas de estabilização
Decaimento bacteriano
Coliformes termotolerantes
Enterococcus sp.
topic Lagoas de estabilização
Decaimento bacteriano
Coliformes termotolerantes
Enterococcus sp.
Stabilization ponds
Bacterial decay
Thermotolerant coliform
Enterococcus sp.
CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA
dc.subject.eng.fl_str_mv Stabilization ponds
Bacterial decay
Thermotolerant coliform
Enterococcus sp.
dc.subject.cnpq.fl_str_mv CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA
description Stabilization pond system consisting in more sewage treatment used in Rio Grande do Norte (RN), Brazil, representing about 90% of all systems. Fecal bacteria are removed mainly facultative ponds and in maturation ponds. Many factors influence bacterial decay, such as the levels of pH and DO, temperature, light intensity, HDT and nutrient availability. The bacterial decay rate (Kb) is calculated considering many variables, but the hydraulic regime is a significant influence for microorganisms removal, and the dispersed flow which best characterizes a stabilization pond. However, some authors developed equations for the Kb accordant plug flow and complete mixing. This research study aimed to evaluate the bacterial decay of fecal coliform and Enterococcus sp. in stabilization ponds designed to treat domestic sewage, full-scale, in RN. All systems have assessed pretreatment, a facultative pond (LF) followed by two maturation (LM1 and LM2). The parameters availed were: temperature, pH, DO, BOD5, COD, fecal coliform, Enterococcus sp., Chlorophyll a, total suspended solids, fixed and volatile. In general, there were not significant differences for pH, DO and temperature in the ponds, except for the new systems, since they have low flow and hydraulic loads. The removal of organic matter in the ponds was low, about 70%, and nearly all are overloaded organic and operational problems. The bacterial removals were low, with average 96% for LF for fecal coliform, and 98% for Enterococcus sp.; LM1 were in itself a removal for fecal coliform about 71%, and 81% for Enterococcus sp.; LM2 have efficiency of 69% for fecal coliform, and 68% for Enterococcus sp. The equation proposed by Von Sperling (1999), according to the dispersed flow regime, generated empirical values of Kb more approximate to calculated values of Kb. On average, the calculated Kb to coliforms in the LF was 0.31 d-1, and for both maturation ponds were 0.35 d-1. For Enterococcus sp. the average was 0.40 d-1 for LF, 0.55 d-1 for LM1, and 0.58 d-1 for LM2. These results also showed that the Kb obtained in full-scale systems are smaller than those found in pilot-scale ponds. Moreover, one can say that the equation proposed by Marais (1974), according to the complete-mix regime, overestimates Kb. Actual results of Kb indicated that fecal coliforms are more resistant to adverse conditions present in stabilization ponds than Enterococcus sp., therefore, an indicator of microbiological safety and efficiency. The factors significant interventions in the rate of bacterial decay were concentrations of COD, the organic loading and HDT. The few Kb relationship between pH, DO and temperature were not significant. Finally, we conclude that it s essential to correct operation and maintenance, for not performing these activities is one of the main factors contributing to low rates of bacterial decay.
publishDate 2011
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dc.identifier.citation.fl_str_mv TORRES, Dayana Melo. Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro. 2011. 99 f. Dissertação (Mestrado em Saneamento Ambiental; Meio Ambiente; Recursos Hídricos e Hidráulica) - Universidade Federal do Rio Grande do Norte, Natal, 2011.
dc.identifier.uri.fl_str_mv https://repositorio.ufrn.br/jspui/handle/123456789/15977
identifier_str_mv TORRES, Dayana Melo. Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro. 2011. 99 f. Dissertação (Mestrado em Saneamento Ambiental; Meio Ambiente; Recursos Hídricos e Hidráulica) - Universidade Federal do Rio Grande do Norte, Natal, 2011.
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dc.publisher.department.fl_str_mv Saneamento Ambiental; Meio Ambiente; Recursos Hídricos e Hidráulica
publisher.none.fl_str_mv Universidade Federal do Rio Grande do Norte
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