33 research outputs found
Tratamento de efluentes da indústria de conservas de peixe com vista à sua reutilização
É de grande interesse ambiental e económico estudar o tratamento de
efluentes da indústria de conservas de peixe de forma a obter uma água com os requisitos
de qualidade necessários para considerar a sua reutilização e/ou reciclagem para a unidade
industrial. No entanto, o elevado conteúdo de sal tem sido um fator limitante, pois persiste
mesmo após o tratamento convencional dos efluentes. Assim, foi estudado e otimizado
um processo de clarificação por filtração rápida, osmose inversa e desinfeção UV, como
tratamento de afinação do efluente previamente tratado, de modo a remover sólidos, sais e
microrganismos remanescentes. Este tratamento de afinação permitiu alcançar eficiências
de remoção de 78% de sólidos suspensos totais, 97,3% de carbono orgânico dissolvido,
99,8% de azoto total solúvel, 99,1% de condutividade, acima de 96% de aniões e catiões e
100% de bactérias heterotróficas (UFC), atingindo-se, como pretendido, água com os
requisitos de qualidade necessários para ser reutilizada ou reciclada para a unidade
industrial. Consequentemente, é possível uma redução da descarga de efluentes, uma
limitação do uso de água e uma redução dos custos associados.Este trabalho é parcialmente suportado pelo projeto PEst C/EQB/LA0020/2013, financiado pela FEDER através do Programa Operacional Fatores de Competitividade –COMPETE e pela Fundação para a Ciência e a Tecnologia –FCT e pelo projeto em co-promoção I&DT QREN nº 13634, ValorPeixe –
Valorização de Subprodutos e Águas Residuais da Indústria de Conservas de Peixe, financiado pela FEDER através do Programa Operacional Fatores de Competitividade POFC aos quais os autores se encontram agradecidos. Os autores querem também agradecer à indústria de conservas em estudo pelas amostras de efluente. A autora Raquel O. Cristóvão agradece também à FCT pela bolsa de Pós-doutoramento (SFRH/BPD/81564/2011).info:eu-repo/semantics/publishedVersio
Fish canning industry wastewater treatment for water reuse – a case study
The valorization of wastewaters from the fish canning industry is of great concern, not only because of
the high quantities generated, but also economic and environmental benefits may result from a proper
treatment approach of the waste generated while reducing costs related to wastewater discharge.
A limiting factor for reuse and recycling treated fish canning wastewater into an industrial plant and
also for other uses is the high salt content, which persists even after conventional treatment. So, the
reuse of fish canning industrial wastewater was assessed by combining conventional treatments, such as
sedimentation, chemical coagulation-flocculation and aerobic biological degradation (activated sludge
process) followed by a polishing step by reverse osmosis (RO) and ultraviolet (UV) disinfection.
In this investigation all these processes were optimized in order to remove essentially the effluent
suspended particles (primary treatment), the organic matter content in the biological aerated reactor
(secondary treatment) and, finally, the remaining salts and microorganisms (tertiary treatment).
The overall removal efficiencies obtained were: 99.9% for dissolved organic carbon (DOC), 99.8% for oil
and grease (O&G), 98.4% for total suspended solids (TSS), above 96% for anions and cations and 100% for
heterotrophic bacteria expressed as colony-forming units (CFU). The final clarified effluent was found to
have the quality requirements to be recycled or reused in the industrial plant, allowing the reduction of
the effluent to be discharged, the water use and the costs of tap water for industrial use.
As regards the energy and chemicals costs, to obtain a treated effluent to be reused in the process costs
0.85 V/m3. This value can be reduced by about 60% if the goal is only to meet the legislated standards for
the effluent discharge into water bodies. Tap water for the industrial plant costs about 2.1 V/m3.This work is partially supported by project PEst-C/EQB/LA0020/2013,financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundação para a
Ciência e a Tecnologia and by ValorPeixe - Valorizaçãode Sub-produtos e Águas Residuais da Indústria de Conservas de Peixe, project in co-promotion I&DT QREN, nº13634,financed by FEDER through POFC - Programa Operacional Factores de Competitividade for which the authors are thankful.
Raquel O. Cristóvão thanks FCT for the Post-doc Scholarship (SFRH/BPD/81564/2011).info:eu-repo/semantics/publishedVersio
Primary treatment optimization of a fish canning wastewater from a Portuguese plant
A sequence with three stages was optimized as a primary treatment for wastewaters from a fish canning industry of northern Portugal. Sedimentation tests were assessed at different times. The removal of a high fraction (75%) of oil and grease (O&G) and of some (48%) total suspended solids (TSS) occurred after a settling time of 1.5h. Coagulant dosage and pH value were optimized in the coagulation/flocculation treatment using several organic and inorganic coagulants. Best removal efficiencies (99.2% O&G, 85.8% TSS and 25.2% dissolved organic carbon (DOC)) were reached using 400mg/L of FeCl3 at raw pH wastewater. DAF was also tested, optimizing chamber pressure and recycle ratio. Removals of 94% for O&G and 43% for TSS were achieved. The coupling of the latter two processes was also investigated, but no improvement of the previous results was observed. The best approach proved to be a decantation process followed by coagulation/flocculation treatment. © 2014 The Authors
Endoparasites of Polygenis tripus (Siphonaptera: Rhopalopsyllidae) of wild rodents from Belo Horizonte, Minas Gerais, Brazil
Ectoparasitos de pequenos mamíferos da Ilha de Maracá, Roraima, Brasil. II. interação entre ectoparasitos e hospedeiros.
The total index of fleas, lice and acari were determined on mammals captured in Maracá Island, Roraima State, Brazil, from November 1987 to February 1989, In view of the limiting or critical values attributed to flea index, proposed as a complementary measure for plague surveillance, some wild rodent would have been exposed to this infec-tion. The total indexwas11.5 and the prevalent flea was Polygenis klagesi klagesi,observed in the dry season. The highest numbers of ectopanasites per host were: 244 for Proechimys guyannensis,193 for Proechimyssp. and 108 for Botomyssp. Species with the highest indices of infestation were P. klagesi klagesion Proechimyssp.; Gliricolasp. ri., Tur apicalisand Tur. aymaraon P. guyannensis. The single infestations were the most prevalent, while the double and others were equivalent. With the exception of proe chimyssp., all species of hosts presented single infestation . Only Laelaps dearmsiand Gliricola porcellioccurred in single infestations.Indices globais pulicidianos, anoplurianos, malofagianos e acarianos foram determinados em mamiferos capturados na Ilha de Manacá, Roraima, Brasil, no periodo de, novembro de 1987 a fevereiro de 1989.Tendo-se em vista os valores limites ou criticas atri-buidos aos indices pulicidianos, propostos como medida complementar de vigilância epide-miológica para peste, alguns, roedores silvestres poderiam ter estado expostos a esta in-fecção. O indice global foi de 11,5e a pulga prevalente foi Polygznis klagesi klagesiobservado na estação seca. Os números máximos de ectoparasitas por hospedeiros foram244 para Prorchimys guyannensis, 193para Prorchimyssp. e 108 para Bolomys sp. As espéciescom indices de infestação mais elevados fonam P. klagesi klagesiem Peoechimyssp.; Glíricolasp. n., Tur apicalise Tur aymaraem P. guyannensis.infestações simples foram de mais prevalentes, enquanto as duplas e as outras múltiplas foram equivalentes. Com exceção deProechimyssp., todas as espécies de hospedeiros apresentaram infestações simples. Apenas Laelaps dearmasie Gliricola porcelliocorreram em infestações iso-ladas
Fish canning wastewater treatment by activated sludge: Application of factorial design optimization. Biological treatment by activated sludge of fish canning wastewater.
The optimization of hydraulic retention time (HRT) and initial organic matter concentration for dissolved organic carbon (DOC) abatement of wastewater from a fish canning industry of northern Portugal by activated sludge was investigated using response surface methodology (RSM). The two parameters were chosen since it was found that the treatment efficiency is mainly influenced by them. The experimental data on DOC r emoval were fitted into a quadratic polynomial model using factorial design and RSM. The optimum process conditions were determined by analyzing the response surface of a three-dimensional plot and by solving the regression model equation. The obtained results showed a HRT of 6.4. h and an initial DOC of 406.2. mg/L as the best treatment conditions. Under these conditions, the maximum predicted DOC removal was 88.0%, confirming the feasibility and the reliability of fish canning wastewater treatment by activated sludge for organic content removal.This work is partially supported by project PEst-C/EQB/LA0020/2011, financed byFEDER through
COMPETE – Programa Operacional Factores de Competitividade and by FCT – Fundação para a Ciência e a
Tecnologia and by project Valor Peixe – Valorização de Subprodutos e Águas Residuais da Indústria de
Conservas de Peixe, projectinco-promotion I&DTQREN, No.13634, financed by FEDER through POFC –
Programa Operacional Factores de Competitividade for which the authors are thankful.The authors
also wish to thank the cannery in study for wastewater samples.Authors also thank FCT for the Post-
doc Scholarship (SFRH/BPD/81564/2011).info:eu-repo/semantics/publishedVersio
Noteworthy records of Ixodes auritulus Neumann, 1904 (Acari, Ixodida) on birds from Paraná, southern Brazil
Ectoparasitos de roedores da região urbana de Belo Horizonte, MG. I. Interação entre ectoparasitos e hospedeiros
Pediculose capitis: prevalência em escolares da Rede Municipal Pública de Belo Horizonte, Minas Gerais, Brasil
During 1985, 50,356 children and adolecents from 105 public schools of Belo Horizonte, Minas Gerais State were questioned about or examined for head lice (Pediculus capitis). The mean prevalence of pediculosis, obtainde from the questionnaires and sometimes confirmed by head inspections, was 7.7% or else 10.2% when adjusted to 38,311 respondents. Current and past infestations combined - within a period of three months before survey - revealed a total prevalence of 57.4%. Significant differences were observed among socioeconomic levels, and grades of school age. The more prevalent categories among the factors studied were: sex - femal: 9.2% (P<0.001); ethnic group - white: 10.0% (P<0.001); hair length - long: 9.5% (P<0.05); year age-group - 1-5 years: 19.2% (P<0.001), with a peak in the 5th year (21.3%)
Infestação por Pediculus humanus (Anoplura: Pediculidae) no Município de São Paulo, SP, Brasil
Adults, nymphs and nits of the Pediculus humanus were found in a frame-house infesting the clothes and bedding of three inhabitants in a shanty town in S. Paulo county, S. Paulo State. A total of 198 nits were found glued in 15.0 cm² of fibres of the infested clothing, giving a ratio of 13.2 nits/cm². Having in view that the precarious living conditions, promiscuity, absence of basic sanitation and negligence of the sanitary authorities in various Brazilian cities, this situation should not be underestimated. This find should be more frequent than an isolated observation.Adultos, ninfas e lêndeas da espécie Pediculus humanus foram encontrados em barraco, infestando roupas de cama e vestes de três habitantes em uma favela na cidade de São Paulo, Estado de São Paulo, Brasil. Lêndeas, num total de 198, foram encontradas aderidas em 15,0 cm² de fibras de vestes infestadas, dando uma média de 13,2 por cm². Dada a freqüência em diversas cidades do Brasil, de precárias condições de vida, promiscuidade, ausência de saneamento básico e negligência das autoridades sanitárias tal ocorrência poderá ser maior do que um simples caso isolado