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Blackburn meadows wastewater treatment works

Lima, R.; Bachmann, R.
Fonte: Inderscience Publicador: Inderscience
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Blackbum Meadows wastewater treatment works is situated in Sheffield, the fourth largest city in England, in the county of South Yorkshire. This treatment plant has a fluidized bed incinerator in order to treat and dispose the sludge. This paper gives a brief overview of the various stages and processes involved in effluent treatment at Blackbum Meadows and assesses the sludge disposal operation.

Primary treatment optimization of a fish canning wastewater from a Portuguese plant

Cristovão, Raquel; Botelho, Cidália; Martins, Ramiro; Loureiro, José; Boaventura, Rui
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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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.

Chemical oxidation of fish canning wastewater by fenton’s reagent

Cristovão, Raquel; Gonçalves, Cristiana; Botelho, Cidália; Martins, Ramiro; Boaventura, Rui
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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The fish canning industry generates large volume of wastewater for which the treatment is particularly difficult due to the high content of organic matter and salts and to the significant amount of oil and grease they present. In this work, a closed jacketed batch reactor was used to study the feasibility of applying a Fenton reaction step after an activated sludge biological treatment. For this purpose and in order to find optimal conditions, a 33 Box-Behnken full factorial design was used. The predicted optimum value (64% DOC degradation) was found for hydrogen peroxide concentration of 1520 mg/L, iron concentration of 338 mg/L and pH 3.2.

Tratamento anaeróbio de pentaclorofenol em reator de leito fluidificado alimentado com água residuária sintética contendo glicose como fonte única de carbono; Anaerobic treatment of pentachlorophenol in a fluidized bed reactor fed with synthetic wastewater containing glucose as a single carbon source

FREIRE, Flavio Bentes; PIRES, Eduardo Cleto; FREIRE, José Teixeira
Fonte: ABES Publicador: ABES
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Neste trabalho foi utilizado um reator anaeróbio de leito fluidificado (RALF), tratando água residuária sintética contendo pentaclorofenol (PCP), submetido a condições operacionais menos idealizadas. Utilizou-se um reator com volume de 16 litros, com partículas de carvão ativado granular como meio suporte. O desempenho do reator foi verificado pelas análises usuais de monitoramento (pH, alcalinidade, DQO, ácidos voláteis) e também por análises de microscopia e concentração de PCP. A presença de PCP no sistema, nas concentrações utilizadas, não alterou de maneira significativa a qualidade da biomassa presente, e nem os parâmetros de monitoramento. Em concentrações afluentes de PCP variando de 1 a 6 mg/L, foram observadas eficiências médias de remoção de 92% e 70%, respectivamente.; In the present work, an anaerobic fluidized bed reactor (AFBR) was used for the treatment of a synthetic wastewater containing pentachlorophenol (PCP) subjected to less idealized operating conditions. The reactor was a 16 litres tank with granular activated carbon particles as support media. Evaluation of AFBR performance was done by the analysis of usual monitoring parameters (pH, alkalinity, COD, volatile acids) together with microscopy and PCP concentration analysis. The presence of PCP under the concentrations used did not significantly alter the amount of biomass and the performance monitoring parameters. Removal average efficiencies of the order of 92% and 70% were obtained for PCP inflow concentrations in the range of 1 to 6mg/l.; Fapesp

Full-scale anaerobic sequencing batch biofilm reactor for sulfate-rich wastewater treatment

SARTI, Arnaldo; SILVA, Ariovaldo J.; ZAIAT, Marcelo; FORESTI, Eugenio
Fonte: DESALINATION PUBL Publicador: DESALINATION PUBL
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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This paper describes the performance and biofilm characteristics of a full-scale anaerobic sequencing batch biofilm reactor (ASBBR; 20 m(3)) containing biomass immobilized on an inert support (mineral coal) for the treatment of industrial wastewater containing a high sulfate concentration. The ASBBR reactor was operated during 110 cycles (48 h each) at sulfate loading rates ranging from 6.9 to 62.4 kgSO(4)(2-)/cycle corresponding to sulfate concentrations of 0.58-5.2 gSO(4)(2-)/L. Domestic sewage and ethanol were utilized as electron donors for sulfate reduction. After 71 cycles the mean sulfate removal efficiency was 99%, demonstrating a high potential for biological sulfate reduction. The biofilm formed in the reactor occurred in two different patterns, one at the beginning of the colonization and the other of a mature biofilm. These different colonization patterns are due to the low adhesion of the microorganisms on the inert support in the start-up period. The biofilm population is mainly made up of syntrophic consortia among sulfate-reducing bacteria and methanogenic archaea such as Methanosaeta spp.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP[03/07799-2]; Conselho Nacional de Desenvolvimento Cientifico e Tecnolgico-CNPq[019/2004]; Conselho Nacional de Desenvolvimento Cientifico e Tecnolgico-CNPq[478355/2004-1]

AnSBBR Applied to the Treatment of Metalworking Fluid Wastewater: Effect of Organic and Shock Load

CARVALHINHA, Pedro P.; FLORES, Anderson; RODRIGUES, Jose A. D.; RATUSZNEI, Suzana M.; ZAIAT, Marcelo; FORESTI, Eugenio
Fonte: HUMANA PRESS INC Publicador: HUMANA PRESS INC
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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An investigation was performed regarding the application of a mechanically stirred anaerobic sequencing batch biofilm reactor containing immobilized biomass on inert polyurethane foam (AnSBBR) to the treatment of soluble metalworking fluids to remove organic matter and produce methane. The effect of increasing organic matter and reactor fill time, as well as shock load, on reactor stability and efficiency have been analyzed. The 5-L AnSBBR was operated at 30 A degrees C in 8-h cycles, agitation of 400 rpm, and treated 2.0 L effluent per cycle. Organic matter was increased by increasing the influent concentration (500, 1,000, 2,000, and 3,000 mg chemical oxygen demand (COD)/L). Fill times investigated were in the batch mode (fill time 10 min) and fed-batch followed by batch (fill time 4 h). In the batch mode, organic matter removal efficiencies were 87%, 86%, and 80% for influent concentrations of 500, 1,000, and 2,000 mgCOD/L (1.50, 3.12, and 6.08 gCOD/L.d), respectively. At 3,000 mgCOD/L (9.38 gCOD/L.d), operational stability could not be achieved. The reactor managed to maintain stability when a shock load twice as high the feed concentration was applied, evidencing the robustness of the reactor to potential concentration variations in the wastewater being treated. Increasing the fill time to 4 h did not improve removal efficiency...

Effect of Fill Time on the Performance of Pilot-scale ASBR and AnSBBR Applied to Sanitary Wastewater Treatment

NOVAES, Luciano Farias de; BORGES, Lucas Oliveira; RODRIGUES, Jose Alberto Domingues; RATUSZNEI, Suzana Maria; ZAIAT, Marcelo; FORESTI, Eugenio
Fonte: HUMANA PRESS INC Publicador: HUMANA PRESS INC
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Many lab-scale studies have been carried out regarding the effect of feed strategy on the performance of anaerobic sequencing batch reactors (ASBR); however, more detailed pilot-scale studies should be performed to assess the real applicability of this type of operation. Therefore, the objective of this work was to assess the effect of feed strategy or fill time in a 1-m(3) mechanically stirred pilot-scale sequencing batch reactor, treating 0.65 m(3) sanitary wastewater in 8-h cycles at ambient temperature. Two reactor configurations were used: one containing granular biomass (denominated ASBR) and the other immobilized biomass on polyurethane foam as inert support (denominated anaerobic sequencing batch biofilm reactor (AnSBBR)). The reactors were operated under five distinct feed strategies, namely: typical batch and fed-batch for 25%, 50%, 75%, and 100% of the cycle length. Stirring frequency in the ASBR was 40 rpm with two flat-blade turbine impellers and 80 rpm in the AnSBBR with two helix impellers. The results showed that both the ASBR and AnSBBR when operated under typical batch, fed-batch for 50% and 75% of the cycle length, presented improved organic matter removal efficiencies, without significant differences in performance...

The treatment of sulfate-rich wastewater using an anaerobic sequencing batch biofilm pilot-scale reactor

SARTI, Arnaldo; SILVA, Ariovaldo J.; ZAIAT, Marcelo; FORESTI, Eugenio
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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This paper presents the results from 92 cycles of an anaerobic sequencing batch biofilm reactor containing biomass immobilized on inert support (mineral coal) applied for the treatment of an industrial wastewater containing high sulfate concentration. The pilot-scale reactor, with a total volume of 1.2 m(3), was operated at sulfate loading rates ranging from 0.15 to 1.90 kgSO(4)(2-)/cycle (48 It - cycle) corresponding to sulfate concentrations of 0.25 to 3.0 gSO(4)(2-) l(-1). Domestic sewage and ethanol were utilized as electron donors for sulfate reduction. Influent sulfate concentrations were increased in order to evaluate the minimum COD/sulfate ratio at which high reactor performance could be maintained. The mean sulfate removal efficiency remained between the range of 88 to 92% at several sulfate concentrations. Temporal profiles along the 48 h cycles were carried out under stable operation at sulfate concentrations of 1.0, 2.0 and 3.0 gSO(4)(2-) l(-1). Sulfate removal reached 99% for cycle times of 15, 25, and 30 h, and the effluents sulfate concentrations were lower than 8 mgSO(4)(2-) l(-1). The results demonstrate the potential applicability of the anaerobic configuration for the biological treatment of sulfate-rich wastewaters. (C) 2009 Elsevier B.V. All rights reserved.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP[03/07799-2]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq[019/2004]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq[478355/2004-1]

Morphological and molecular characterization of cyanobacteria from a Brazilian facultative wastewater stabilization pond and evaluation of microcystin production

FURTADO, Ana Luiza Fonseca Fortes; CALIJURI, Maria do Carmo; LORENZI, Adriana Sturion; HONDA, Ricardo Yukio; GENUARIO, Diego Bonaldo; FIORE, Marli Fatima
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
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The cyanobacterial population in the Cajati waste stabilization pond system (WSP) from Sao Paulo State, Brazil was assessed by cell isolation and direct microscope counting techniques. Ten strains, belonging to five genera (Synechococcus, Merismopedia, Leptolyngbya, Limnothrix, and Nostoc), were isolated and identified by morphological and molecular analyses. Morphological identification of the isolated strains was congruent with their phylogenetic analyses based on 16S rDNA gene sequences. Six cyanobacterial genera (Synechocystis, Aphanocapsa, Merismopedia, Lyngbya, Phormidium, and Pseudanabaena) were identified by direct microscope inspection. Both techniques were complementary, since, of the six genera identified by direct microscopic inspection, only Merismopedia was isolated, and the four other isolated genera were not detected by direct inspection. Direct microscope counting of preserved cells showed that cyanobacteria were the dominant members (> 90%) of the phytoplankton community during both periods evaluated (summer and autumn). ELISA tests specific for hepatotoxicmicrocystins gave positive results for six strains (Synechococcus CENA108, Merismopedia CENA106, Leptolyngbya CENA103, Leptolyngbya CENA112, Limnothrix CENA109...

Effect of impeller type and mechanical agitation on the mass transfer and power consumption aspects of ASBR operation treating synthetic wastewater

MICHELAN, Rogerio; ZIMMER, Thiago R.; RODRIGUES, Jose A. D.; RATUSZNEI, Suzana M.; MORAES, Deovaldo de; ZAIAT, Marcelo; FORESTI, Eugenio
Fonte: ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD Publicador: ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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The effect of flow type and rotor speed was investigated in a round-bottom reactor with 5 L useful volume containing 2.0 L of granular biomass. The reactor treated 2.0 L of synthetic wastewater with a concentration of 800 mgCOD/L in 8-h cycles at 30 degrees C. Five impellers, commonly used in biological processes, have been employed to this end, namely: a turbine and a paddle impeller with six-vertical-flat-blades, a turbine and a paddle impeller with six-45 degrees-inclined-flat-blades and a three-blade-helix impeller. Results showed that altering impeller type and rotor speed did not significantly affect system stability and performance. Average organic matter removal efficiency was about 84% for filtered samples, total volatile acids concentration was below 20 mgHAc/L and bicarbonate alkalinity a little less than 400 mgCaCO(3)/L for most of the investigated conditions. However, analysis of the first-order kinetic model constants showed that alteration in rotor speed resulted in an increase in the values of the kinetic constants (for instance, from 0.57 h(-1) at 50 rpm to 0.84 h(-1) at 75 rpm when the paddle impeller with six-45 degrees-inclined-flat-blades was used) and that axial flow in mechanically stirred reactors is preferable over radial-flow when the vertical-flat-blade impeller is compared to the inclined-flat-blade impeller (for instance at 75 rpm...

Anaerobic treatment of sulfate-rich wastewater in an anaerobic sequential batch reactor (AnSBR) using butanol as the carbon source

SARTI, Arnaldo; ZAIAT, Marcelo
Fonte: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD Publicador: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.71%
Biological sulfate reduction was studied in a laboratory-scale anaerobic sequential batch reactor (14 L) containing mineral coal for biomass attachment. The reactor was fed industrial wastewater with increasingly high sulfate concentrations to establish its application limits. Special attention was paid to the use of butanol in the sulfate reduction that originated from melamine resin production. This product was used as the main organic amendment to support the biological process. The reactor was operated for 65 cycles (48 h each) at sulfate loading rates ranging from 2.2 to 23.8 g SO(4)(2-)/cycle, which corresponds to sulfate concentrations of 0.25, 0.5,1.0, 2.0 and 3.0 g SW(4)(2-)L(-1). The sulfate removal efficiency reached 99% at concentrations of 0.25, 0.5 and 1.0 g SO(4)(2-)L(-1). At higher sulfate concentrations (2.0 and 3.0 g SO(4)(2-)L(-1)), the sulfate conversion remained in the range of 71-95%. The results demonstrate the potential applicability of butanol as the carbon source for the biological treatment of sulfate in an anaerobic batch reactor. (C) 2011 Elsevier Ltd. All rights reserved.; FAPESP-Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Brazil[07/08335-0]

Reclaimed wastewater: Impact on soil-plant system under tropical conditions

PEREIRA, B. F. F.; HE, Z. L.; SILVA, M. S.; HERPIN, U.; NOGUEIRA, S. F.; MONTES, C. R.; MELFI, A. J.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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This study investigated the ionic speciation of reclaimed urban wastewater (RWW), and the impact of increasing RWW irrigation rates on soil properties and plant nutrition under field conditions. Most RWW elements (>66%) are readily available as NH(4)(+), Ca(2+), Mg(2+), K(+), SO(4)(2-), Cl(-), H(3)BO(3), Mn(2+) and Zn(2+), but in imbalanced proportion for plant nutrition. Lead, Cd, Cr and Al in RWW are mostly bounded with DOM or OH. Irrigation with RWW decreased soil acidity, which is beneficial to the acidic tropical soil. Although RWW irrigation builds exchangeable Na(+) up, the excessive Na(+) was leached out of the soil profile after a rainy summer season (>400 mm). Benefits of the disposal of RWW to the soil under tropical conditions were discussed, however, the over irrigation with RWW (>100% of crop evapotranspiration) led to a nutritional imbalance, accumulating S and leading to a plant deficiency of P and K. (C) 2011 Elsevier B.V. All rights reserved.; FAPESP (Sao Paulo Research Foundation)[06/56419-6]; FAPESP (Sao Paulo Research Foundation)[04/14315-4]

Dynamics of Aeromonas species isolated from wastewater treatment system

MARTONE-ROCHA, S.; PIVELI, R. P.; MATTE, G. R.; DORIA, M. C.; DROPA, M.; MORITA, M.; PETERNELLA, F. A.; MATTE, M. H.
Fonte: IWA PUBLISHING Publicador: IWA PUBLISHING
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Aeromonas are widely distributed in the aquatic environment, and are considered to be emerging organisms that can produce a series of virulence factors. The present study was carried out in a sanitary sewage stabilization pond treatment system, located in Lins, State of Sao Paulo, Brazil. Most probable number was applied for estimation of the genus Aeromonas. Colony isolation was carried out on blood agar ampicillin and confirmed by biochemical characterization. Aeromonas species were isolated in 72.4% of influent samples, and in 55.2 and 48.3% of effluent from anaerobic and facultative lagoons, respectively. Thirteen Aeromonas species were isolated, representing most of the recognized species of these organisms. Even though it was possible to observe a tendency of decrease, total elimination of these organisms from the studied system was not achieved. Understanding of the pathogenic organism`s dynamics in wastewater treatment systems with a reuse potential is especially important because of the risk it represents.; Programa de Saneamento Ambiental PROSAB/Finep/CNPq (Brazil)

Cassava wastewater as a substrate for the simultaneous production of rhamnolipids and polyhydroxyalkanoates by Pseudomonas aeruginosa

COSTA, Siddhartha G. V. A. O.; LEPINE, Francois; MILOT, Sylvain; DEZIEL, Eric; NITSCHKE, Marcia; CONTIERO, Jonas
Fonte: SPRINGER HEIDELBERG Publicador: SPRINGER HEIDELBERG
Tipo: Artigo de Revista Científica
Português
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Glycerol, cassava wastewater (CW), waste cooking oil and CW with waste frying oils were evaluated as alternative low-cost carbon substrates for the production of rhamnolipids and polyhydroxyalkanoates (PHAs) by various Pseudomonas aeruginosa strains. The polymers and surfactants produced were characterized by gas chromatography-mass spectrophotometry (MS) and by high-performance liquid chromatography-MS, and their composition was found to vary with the carbon source and the strain used in the fermentation. The best overall production of rhamnolipids and PHAs was obtained with CW with frying oil as the carbon source, with PHA production corresponding to 39% of the cell dry weight and rhamnolipid production being 660 mg l(-1). Under these conditions, the surface tension of the culture decreased to 30 mN m(-1), and the critical micelle concentration was 26.5 mg l(-1). It would appear that CW with frying oil has the highest potential as an alternative substrate, and its use may contribute to a reduction in the overall environmental impact generated by discarding such residues.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biohydrogen production from cassava wastewater in an anaerobic fluidized bed reactor

Amorim,N. C. S.; Alves,I.; Martins,J. S.; Amorim,E. L. C.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 Português
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The effect of hydraulic retention time (HRT) and organic loading rate (OLR) on biological hydrogen production was assessed using an anaerobic fluidized bed reactor fed with cassava wastewater. The HRT of this reactor ranged from 8 to 1 h (28 to 161 kg COD/m³-d). The inoculum was obtained from a facultative pond sludge derived from swine wastewater treatment. The effluent pH was approximately 5.00, while the influent chemical oxygen demand (COD) measured 4000 mg COD/L. The hydrogen yield production increased from 0.13 to 1.91 mol H2/mol glucose as the HRT decreased from 8 to 2 h. The hydrogen production rate significantly increased from 0.20 to 2.04 L/h/L when the HRT decreased from 8 to 1 h. The main soluble metabolites were ethanol (1.87-100%), acetic acid (0.00-84.80%), butyric acid (0.00-66.78%) and propionic acid (0.00-50.14%). Overall, we conclude that the best hydrogen yield production was obtained at an HRT of 2 h.

Degradation of organic pollutants and characteristics of activated sludge in an anaerobic/anoxic/oxic reactor treating chemical industrial wastewater

Wang,Dong; Ji,Min; Wang,Can
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 Português
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A laboratory-scale anaerobic/anoxic/oxic system operated at the hydraulic retention times (HRT) of 20, 40, and 60 h with mixed liquor suspended solids (MLSS) concentrations of 3 g/L and 6 g/L was considered for treating chemical industrial wastewater rich in complex organic compounds and total dissolved solids. Extending the HRT and increasing the MLSS concentration resulted in higher removal efficiency for chemical oxygen demand at 72%. Organic compounds in wastewater could be classified into easily-removed and refractory compounds during treatment. The easily-removed compounds consisted primarily of ethers, alcohols, and aldehydes, whereas the refractory compounds included mainly oxygen-containing heterocyclic and benzene-containing compounds. Results from energy-dispersive X-ray spectroscopy showed that several metal ions accumulated in activated sludge, particularly Fe(III). Fe accumulated mainly on the surface of sludge floc pellets and resulted in the compactness of activated sludge, which caused the values of mixed liquor volatile suspended solids /MLSS and sludge volume index to decrease.

Cultivation of Nannochloropsis sp. in brackish groundwater supplemented with municipal wastewater as a nutrient source

Sousa,Louise Lins de; Hora,Dominique Silveira da; Sales,Emerson Andrade; Perelo,Louisa Wessels
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2014 Português
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The aim of this work was to study growth potential of the green microalgae Nannochloropsis sp. using brackish groundwater from a well in the semi-arid northeast region of Brazil as culture medium. The medium was supplemented with (%) 19.4, 22.0, 44.0 and 50.0% of municipal wastewater after UASB treatment as a low-cost nutrient source. The results showed that the culture tested was capable of growing in the brackish groundwater even at salinity levels as low as 2 ppt. Furthermore it was shown that municipal wastewater could be used as a sole nutrient source for Nannochloropsis sp.

Performance of an Anaerobic Baffled Reactor (ABR) in treatment of cassava wastewater

Ferraz,Fernanda M.; Bruni,Aline T.; Del Bianchi,Vanildo L.
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2009 Português
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The performance of an anaerobic baffled reactor (ABR) was evaluated in the treatment of cassava wastewater, a pollutant residue. An ABR divided in four equal volume compartments (total volume 4L) and operated at 35°C was used in cassava wastewater treatment. Feed tank chemical oxygen demand (COD) was varied from 2000 to 7000 mg L-1 and it was evaluated the most appropriated hydraulic retention time (HRT) for the best performance on COD removal. The ABR was evaluated by analysis of COD (colorimetric method), pH, turbidity, total and volatile solids, alkalinity and acidity. Principal component analysis (PCA) was carried to better understand data obtained. The system showed buffering ability as acidity decreased along compartments while alkalinity and pH values were increased. There was particulate material retention and COD removal varied from 83 to 92% for HRT of 3.5 days.

A DNA pooling based system to detect Escherichia coli virulence factors in fecal and wastewater samples

Luz María Chacón,J; Lizeth Taylor,C; Carmen Valiente,A; Irene Alvarado,P; Ximena Cortés,B
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 Português
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The availability of a useful tool for simple and timely detection of the most important virulent varieties of Escherichia coli is indispensable. To this end, bacterial DNA pools which had previously been categorized were obtained from isolated colonies as well as selected in terms of utilized phenotype; the pools were assessed by two PCR Multiplex for the detection of virulent E. coli eaeA, bfpA, stx1, stx2, ipaH, ST, LT, and aatA genes, with the 16S gene used as DNA control. The system was validated with 66 fecal samples and 44 wastewater samples. At least one positive isolate was detected by a virulent gene among the 20 that were screened. The analysis of fecal samples from children younger than 6 years of age detected frequencies of 25% LT positive strains, 8.3% eae, 8.3% bfpA, 16.7% ipaH, as well as 12.5 % aatA and ST. On the other hand, wastewater samples revealed frequencies of 25.7% eaeA positive, 30.3% stx1, 15.1% LT and 19.7% aatA. This study is an initial step toward carrying out epidemiological field research that will reveal the presence of these bacterial varieties.

Impact of treated wastewater irrigation on antibiotic resistance in the soil microbiome

Gatica, Joao; Cytryn, Eddie
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: text
Português
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The reuse of treated wastewater (TWW) for irrigation is a practical solution for overcoming water scarcity, especially in arid and semiarid regions of the world. However, there are several potential environmental and health-related risks associated with this practice. One such risk stems from the fact that TWW irrigation may increase antibiotic resistance (AR) levels in soil bacteria, potentially contributing to the global propagation of clinical AR. Wastewater treatment plant (WWTP) effluents have been recognized as significant environmental AR reservoirs due to selective pressure generated by antibiotics and other compounds that are frequently detected in effluents. This review summarizes a myriad of recent studies that have assessed the impact of anthropogenic practices on AR in environmental bacterial communities, with specific emphasis on elucidating the potential effects of TWW irrigation on AR in the soil microbiome. Based on the current state of the art, we conclude that contradictory to freshwater environments where WWTP effluent influx tends to expand antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes levels, TWW irrigation does not seem to impact AR levels in the soil microbiome. Although this conclusion is a cause for cautious optimism regarding the future implementation of TWW irrigation...