Isolation of Enterobacteriaceae strains carrying mcr-1 resistance gene from Shanghai wastewater treatment plants and quantification of their copy number / 上海预防医学

ObjectiveTo provide technical support for the molecular surveillance of pathogenic bacteria strains carrying mobile colistin resistance-1 （mcr⁃1） gene isolate from inlet of wastewater treatment plants （WWTP）. MethodsThe Enterobacteriaceae strains carrying mcr⁃1 resistance gene isolate from inlet of WWTP during April 1 to June 30， 2023 in Shanghai were cultured on blood-rich and SS culture medium and were identified using a mass spectrometry analyzer. The mcr⁃1 gene and copy number were detected by real-time fluorescence quantitative PCR. Drug susceptibility test was performed by microbroth dilution method. The copy numbers of Escherichia coli carrying mcr⁃1 gene isolated from wastewater and human fecel were statistically analyzed by SPSS 25.0. ResultsA total of 14 strains carrying the mcr⁃1 gene were isolated from 49 WWTP samples， and the positive isolation rate was 28.6%， including 12 non-diarrheal E. coli strains and 2 Klebsiella pneumoniae strains. The drug susceptibility results showed that all 14 strains were multi-drug resistant bacteria. They were all sensitive to imipenem and tigecycline， but were ampicillin- and cefazolin-resistant. There was no significant difference in the copy number between human-sourced diarrheal E. coli and wastewater-sourced non-diarrheal E. coli （t=0.647， P>0.05）. ConclusionThe isolation and identification of strains carrying the mcr⁃1 gene from inlet of WWTP samples were firstly established in Shanghai. The multi-drug resistance among the isolated strains is severe. To effectively prevent and control the spread of colistin-resistant bacteria， more attention should be paid to the surveillance of mcr⁃1 gene.

Avaliação de ultrafiltração como alternativa à flotação por ar dissolvido no pós-tratamento do efluente de lodos ativados — estudo em escala piloto na estação de tratamento de esgoto Brasília norte / Evaluation of ultrafiltration as an alternative to dissolved air flotation for the post-treatment of activated sludge effluent — pilot study in the Brasília norte wastewater treatment plant

RESUMO A melhoria da qualidade dos efluentes das estações de tratamento de esgotos Brasília Norte e Sul tornou-se premente após o corpo receptor dos seus efluentes, o lago Paranoá, passar a ser utilizado como manancial de abastecimento. Este trabalho apresenta estudo comparativo entre o tratamento terciário por ultrafiltração precedido por coagulação em escala piloto e a flotação por ar dissolvido existente na estação de tratamento de esgotos Brasília Norte. A instalação piloto de ultrafiltração e a flotação por ar dissolvido foram alimentadas pela mesma matriz, o efluente da etapa de lodos ativados das estações de tratamento de esgotos Brasília Norte, após coagulação. Foram avaliadas sete condições operacionais da instalação piloto de ultrafiltração variando-se a vazão, o tempo de operação entre limpezas e a duração da limpeza física. O comportamento operacional e a qualidade do efluente produzido foram monitorados. O aumento do fluxo do permeado (de 40,2 para 50,6 e 61,0 L.m−2.h−1) e do tempo de operação entre as limpezas (de 25 para 38 e 50 min), bem como a redução da duração da retrolavagem (de 80 para 60 e 30 s) resultaram em evolução mais intensa da pressão transmembrana. A ultrafiltração foi mais eficiente do que a flotação por ar dissolvido na remoção de turbidez, sólidos suspensos totais, demanda química de oxigênio e fósforo total, com ganho médio de remoção de 9,4, 13,0, 8,5 e 12,8%, respectivamente. Destaca-se a remoção de coliformes na ultrafiltração, 3,4 log superior à da flotação por ar dissolvido. A utilização da ultrafiltração como alternativa à flotação por ar dissolvido apresenta a vantagem de produzir efluente de melhor qualidade, particularmente no aspecto microbiológico, com menor flutuação da qualidade, porém o tratamento e a destinação do lodo produzido pela ultrafiltração devem ser equacionados.

ABSTRACT Improvement in the effluent quality of the Brasília Norte and Brasília Sul wastewater treatment plants became necessary after their effluent receiving body, Paranoá Lake, started being used as source of drinking water for the population of Brasília (Federal District, Brazil). This is a comparative study between the tertiary treatment with ultrafiltration membrane (pilot scale) and the existing dissolved air flotation of Brasília Norte wastewater treatment plant. Both ultrafiltration pilot plant and dissolved air flotation were fed with the same matrix, the effluent of the activated sludge stage of Brasília Norte wastewater treatment plants, after coagulation. Seven operational conditions were evaluated at ultrafiltration pilot plant, with variations in flow rate, time of operation between cleaning processes, and the duration of backwashing. The operational behavior and the quality of the produced effluent were monitored. The increase in permeate flux (from 40.2 to 50.6 and 61.0 L.m−2.h−1) and in the time of operation between cleaning processes (from 25 to 38 and 50 min), as well as the reduction of backwashing duration (from 80 to 60 and 30s), resulted in a more intense evolution of transmembrane pressure. Ultrafiltration was more efficient than dissolved air flotation in the removal of turbidity, total suspended solids, chemical oxygen demand, and total phosphorous, with average gain in removal of 9.4, 13.0, 8.5, and 12.8%, respectively. It is worth mentioning the removal of coliforms by ultrafiltration, which was, on average, 3.4 log higher than that by dissolved air flotation. The use of ultrafiltration as an alternative to dissolved air flotation has the advantage of producing better quality effluent, particularly regarding microbiological aspects, providing lower quality fluctuation; however, treatment and destination of the ultrafiltration waste must be considered.

Custos de operação e manutenção de estação de tratamento de esgotos por reator anaeróbio e lodos ativados / Operating and maintenance costs of wastewater treatment plant by anaerobic reactor and activated sludge

RESUMO Este trabalho apresentou estudos de custos de operação e manutenção (O&M) na estação de tratamento de esgotos (ETE) de nível terciário, intitulada ETE do Baldo, localizada na cidade de Natal, Rio Grande do Norte. Teve como objetivo avaliar a eficiência econômico-ambiental da ETE através da determinação de indicador de desempenho, calculado via identificação e quantificação de todos os custos operacionais e de manutenção envolvidos nos seus processos internos de tratamento. Na pesquisa, foram identificados os diversos componentes dos custos de O&M responsáveis pelas atividades necessárias ao funcionamento da ETE de julho de 2016 a dezembro de 2018, reunidos em quatro grupos de custos. Os custos mensais foram correlacionados com os dados de vazões do período, e os de O&M por metro cúbico de esgoto tratado ao longo dos anos de 2016, 2017 e 2018 assumiram valores médios de R$ 0,32, R$ 0,30 e R$ 0,38·m−3, respectivamente. Os custos referentes ao pessoal e ao consumo energético exerceram, em todos os meses analisados, o primeiro e o segundo componentes de maior representatividade no custo total, assumindo as seguintes composições percentuais: 56,72 e 26,75% no segundo semestre do ano de 2016; 46,69 e 28,73% no ano de 2017; e 52,44 e 27,56% no ano 2018. Por fim, recomendam-se estudos na implementação de melhorias nos grupos pessoal e energia, tendo em vista que são responsáveis por cerca de 75% de todos os custos de O&M da ETE.

ABSTRACT This study presented operational and maintenance costs (O&M) at the tertiary wastewater treatment plant (WWTP) entitled Baldo's ETE, located in the city of Natal, Rio Grande do Norte. Its aim was to evaluate the economic and environmental efficiency of the WWTP through the determination of a performance indicator, calculated from the identification and quantification of all the operational and maintenance costs involved in its internal processes of treatment. The research identified the various components of O&M costs responsible for the activities necessary for the operation of the WWTP from July 2016 to December 2018, assembled into 4 cost groups. The monthly costs were correlated with the flow data of the period. O&M costs per cubic meter of sewage treated over the years 2016, 2017, and 2018 assumed average values of R$ 0.32, R$ 0.30, and R$ 0.38·m−3, respectively. Personnel and energy consumption costs accounted for the first and second most representative components of the total cost in all the months analyzed, with the following percentage compositions: 56.72 and 26.75% in the second half of 2016; 46.69 and 28.73% in 2017; and 52.44 and 27.56% in the year 2018. Finally, studies on the implementation of improvements in the personal and energy groups are recommended, as they account for about 75% of all O&M costs of the WWTP.

Avaliação de estação de tratamento de esgoto com reator anaeróbio recebendo lodo de estação de tratamento de água Actiflo® / Evaluation of wastewater treatment plant with anaerobic reactor receiving sludge from water treatment plant Actiflo ®

RESUMO O objetivo deste trabalho foi analisar a disposição do lodo do decantador de uma estação de tratamento de água (ETA) com sedimentação lastreada por microareia (Actiflo®) em uma estação de tratamento de esgoto (ETE) composta de upflow anaerobic sludge blanket (UASB) e lagoa de polimento, em Ponta Grossa, Paraná. A ETE Verde operou em condição estável, com uma vazão média afluente de 213,14 L.s-1. Os UASBs operaram com tempo de detenção hidráulica (TDH) de 9,9 horas, carga hidráulica volumétrica de 2,4 m3.m-3.d-1 e carga orgânica volumétrica (COV), em função da demanda química de oxigênio (DQO), variando entre 0,75 e 1,66 kgDQO.m-3.d-1. A lagoa operou com TDH de 4,5 dias, com taxa de aplicação superficial variando entre 765 e 2.872 kgDQO.ha-1.d-1 e COV variando entre 19 e 72 gDQO.m-3.d-1. A eficiência na remoção de DQO e sólidos suspensos totais (SST) foi mantida, mesmo com o lançamento do lodo da ETA. A eficiência da ETE variou entre 80 e 86% para a remoção de DQO e entre 92 e 96% para a remoção de SST. Concluiu-se que o lançamento na rede de esgotos é uma alternativa viável de disposição do lodo do decantador da ETA Actiflo®.

ABSTRACT The objective of this paper was to analyze the disposal of decanter's sludge from a WTP with microsand ballasted sedimentation (Actiflo®) in a WWTP containing UASB reactors and polishing pond, in Ponta Grossa - PR. The WWTP Verde operated in stable condition, with an average flow tributary of 213.14 L.s-1. The UASBs operated with HRT in 9.9 hours, VHL in 2.4 m3.m-3.d-1 and OLR ranging from 0.75 to 1.66 kgCOD.m-3.d-1. The polishing pond operated with HRT in 4.5 days and OLR ranging from 765 to ­2872 ­kgCOD.ha-1.d-1, which corresponds from 19 to 72 gCOD.m-3.d-1. The efficiency of COD and TSS removal was maintained even with the release of WTP sludge. WWTP's efficiency ranged between 80% and 86% for COD removal and between 92% and 96% for TSS. It was concluded that the release in the sewage collection network is a viable alternative to disposal of the decanter's sludge from WTP Actiflo®.

Acompanhamento operacional e avaliação de uma estação compacta de tratamento de esgoto sanitário: reator UASB seguido de filtro aerado submerso / Operational monitoring and evaluation of a compact sanitary wastewater treatment plant: UASB reactor followed by submerged aerated filter

RESUMO Estações Compactas de Tratamento de Efluentes (ECTEs) são uma ótima alternativa para a implantação de sistemas descentralizados de esgoto doméstico que possam atender pequenas comunidades. No entanto, tais sistemas ainda são pouco utilizados e há pouca experiência em relação à sua operação. Diante de tal demanda, esta pesquisa visou avaliar a eficiência e realizar o acompanhamento operacional de uma ECTE composta por reator Upflow Anaerobic Sludge Blanket (UASB), seguido de filtro aerado submerso (FAS), que está localizada no município de Uru, em São Paulo, Brasil. Durante a pesquisa, o sistema mostrou-se uma alternativa viável de tratamento para pequenas comunidades, pois apresentou boa eficiência, com valores médios de remoção de demanda bioquímica de oxigênio (DBO5) e demanda química de oxigênio (DQO) de 91 e 85%, respectivamente. O monitoramento realizado durante a pesquisa também contribuiu para melhorias gerais no sistema.

ABSTRACT Compact Wastewater Treatment Plants (CWTPs) are a great alternative to implementing decentralized sewage systems that can serve small communities. However, such systems are still poorly used and there is little experience regarding their operation. Based on such demand, this research aimed to evaluate the efficiency and to conduct an operational monitoring of a CWTP composed by an Upflow Anaerobic Sludge Blanket (UASB) reactor, followed by Submerged Aerated Filter (SAF), in the city of Uru, São Paulo, Brazil. During the research, the system proved to be a viable alternative for small communities, because it showed good efficiency, with average removal values of biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) of 91 and 85%, respectively. The monitoring carried out during the research also contributed to general improvements in the system.

Distribución de esteroides estrogénicos en plantas de tratamiento de aguas residuales municipales / Distribution of estrogenic steroids in municipal wastewater treatment plants

En la actualidad, existe una preocupación creciente por la presencia de estrógenos en el medio acuático, donde pueden ser introducidos a partir de aguas residuales después de su eliminación incompleta en las plantas de tratamiento. Las aguas residuales sistemáticamente reciben estrógenos naturales y sintéticos, y por lo tanto una comprensión más profunda de la suerte de ellos en el medio ambiente es necesaria. Se evaluaron los niveles de estrógenos en los efluentes de las Plantas de Tratamiento de Aguas Residuales (PTARs) Penha e Ilha do Governador, ambos de tipo convencional de flujo continuo de lodo activado con aireación prolongada. Fue utilizado como el parámetro de determinación de algunos compuestos de interés como estrógenos naturales [estrona (E1), 17β-estradiol (E2), estriol (E3)) y sintéticos (17α-etinilestradiol (EE2)]. Las muestras individuales se recogieron posteriormente al tratamiento de cada PTAR y después de los procedimientos de laboratorio se realizó la determinación de estrógenos basado en la extracción en fase sólida (SPE) y la cromatografía líquida de alta resolución con detector de arreglo de diodos (HPLC-DAD). Las concentraciones fueron de: 0,7 a 5,2 μg/l y de 0,5 a 5,6 de E1; 0,9 a 7,7 y 1,2 a 9,2 μg/l para E2; 2,01 a 6,09 y 1,07 a 4,08 μg/l para EE2 en PTAR Penha y PTAR Ilha do Governador, respectivamente. La capacidad de eliminación de estrógenos fue eficaz, pero denota que la eliminación sistemática de la población es en la actualidad alta. Se recomienda instalar mecanismos para mitigar el consumo exagerado de estas sustancias o implementar una eliminación completa más eficaz.

Currently, there is a growing concern over the presence of estrogens in the aquatic environment, where they can be introduced from wastewater after their incomplete elimination in the treatment plants. Wastewater systematically receives natural and synthetic estrogens, and thus a deeper understanding of the fate of them in the environment is extremely necessary. It was evaluated estrogen levels in the effluent from the Sludge Wastewater Treatment Plants (SWTPs) Penha and Ilha do Governador, both of type conventional continuous-flow activated sludge with extended aeration. The determination of some target compounds as natural estrogens was used as the evaluation parameter [estrone (E1), 17β-estradiol (E2), estriol (E3) and synthetic (17α-ethinylestradiol (EE2)]. Individual samples were collected posterior treatment of each SWTP, and after laboratory procedures, the determination of estrogens was performed by a method based on solid phase extraction (SPE) and high performance liquid chromatography-diode array detector (HPLC-DAD). Concentrations ranged from 0.7 to 5.2 μg/l and from 0.5 to 5.6 for E1; 0.9 to 7.7 and 1.2 to 9.2 μg/l for E2; 2.1 to 6.9 and 1.7 to 4.8 μg/l for EE2 at SWTPs Penha and Ilha do Governador, respectively. The removal capacity of estrogens despite its effectiveness denotes that the systematic elimination by the population is high nowadays and urging mechanisms to mitigate the exaggerated consumption or to implement most effective complete removal.

Ocorrência de diclofenaco e naproxeno em água superficial no município de Três Lagoas (MS) e a influência da temperatura da água na detecção desses anti-inflamatórios / Occurence of diclofenac and naproxen in surface water in the Três Lagoas (MS) city and water temperature influence in the detection of these anti-inflammatories

RESUMO Os objetivos deste trabalho foram avaliar a presença e a concentração dos anti-inflamatórios diclofenaco e naproxeno em um córrego urbano localizado no município de Três de Lagoas, Mato Grosso do Sul, que recebe efluente de uma estação de tratamento de esgoto; e verificar a influência da temperatura da água na ocorrência dos fármacos em águas superficiais. Foi realizado monitoramento dos anti-inflamatórios e dos parâmetros temperatura, pH e oxigênio dissolvido na água durante 12 meses consecutivos (outubro de 2008 a setembro de 2009). Foram coletadas amostras de água mensalmente em seis pontos, representando diferentes seções do córrego. As amostras foram submetidas ao processo de extração em fase sólida e analisadas por cromatografia líquida de alta eficiência. Para verificar a influência da temperatura da água na ocorrência dos anti-inflamatórios diclofenaco e naproxeno nos ambientes aquáticos, utilizou-se um modelo de regressão logística do Statistical Analysis System versão 9.0. Os anti-inflamatórios diclofenaco e naproxeno foram detectados nos diferentes pontos monitorados no Córrego da Onça. Os demais parâmetros avaliados neste estudo foram comparados com os padrões de qualidade de água estabelecidos pela Resolução CONAMA nº 357/2005. A maior concentração do diclofenaco foi detectada no ponto localizado à jusante da estação de tratamento de esgoto do município, enquanto a maior concentração de naproxeno foi registrada na foz do córrego. A temperatura da água influencia de forma inversamente proporcional a ocorrência dos dois anti-inflamatórios no córrego, ou seja, quanto maior a temperatura do corpo hídrico, menor a probabilidade de detecção dos fármacos diclofenaco e naproxeno.

ABSTRACT The aims of this study were to evaluate the presence and concentration of the anti-inflammatory drugs diclofenac and naproxen in an urban stream located in Três Lagoas, Mato Grosso do Sul, Brazil, that receives effluent from a wastewater treatment plant; and to evaluate the influence of water temperature in the occurrence of these drugs into surface waters. Monitoring of both anti-inflammatory and the parameters temperature, pH and dissolved oxygen was held in this water body during 12 consecutive months (October 2008 to September 2009). Water samples were collected monthly at six points representing different sections of the stream. The samples were subjected to solid phase extraction procedure and analyzed by high performance liquid chromatography. To check the influence of water temperature on the occurrence of the anti-inflammatory drugs diclofenac and naproxen in aquatic environments, it was used a logistic model of regression, the Statistical Analysis System version 9.0. The anti-inflammatory drugs diclofenac and naproxen were detected at different points in the Stream of Onça. The other parameters evaluated in this study were compared with the water quality standards established by the CONAMA Resolution 357/2005. The highest concentration of diclofenac was detected in the point located downstream of the wastewater treatment plant of the city, while the largest concentration of naproxen was recorded at the mouth of the stream. The water temperature influence, in an inversely proportional way, the occurrence of both anti-inflammatory in the stream, the higher the temperature the lower the water body probability of detection of drug diclofenac and naproxen.

Levantamento da tipologia das estações de tratamento de esgoto oriundas do Programa de Aceleração do Crescimento e a previsão do impacto no índice de tratamento de esgoto no estado do Espírito Santo / Survey of the type of sewage treatment plants from the Growth Acceleration Program and the forecast impact on the rate of sewage treatment in the state of Espírito Santo, Brazil

RESUMO No âmbito do Programa de Aceleração do Crescimento, cabe ao Ministério das Cidades a gestão de investimentos destinada ao esgotamento sanitário no valor de R$ 26,4 bilhões para implantação ou ampliação do sistema coletor e da estação de tratamento de esgoto. O estado do Espírito Santo foi selecionado para realizar o estudo sobre as tecnologias e avaliar o impacto do aumento do volume de esgoto tratado no índice de tratamento de esgoto (IN046) dos municípios e do estado. Foram identificadas 13 operações com investimentos em tratamento de esgoto, que beneficiam 11 municípios. Estima-se que o valor investido seja de R$ 120.852.842,33, correspondendo a 38,9% do total de recursos em esgotamento sanitário para o estado. As 13 estações de tratamento de esgoto vão proporcionar o aumento de 39.606,69 (x1.000 m³ano-1) de volume do esgoto tratado. O IN046 de oito municípios poderá alcançar o valor de 100,0% e o do estado do Espírito Santo poderá tê-lo alterado de 27,0 para 46,9%, com a entrada em operação dessas estações de tratamento de esgoto.

ABSTRACT Within the scope of the Growth Acceleration Program, the The Brazilian Ministry of Cities is responsible for the management of investments intended for sewage in the amount of BRL 26.4 billion for implementation or expansion of the collection system and wastewater treatment plant. The state of Espírito Santo was chosen to perform the study on the technologies and to evaluate the impact of the increased treated sewage volume in the sewage treatment rate (IN046) of the municipalities and state. It identified 13 operations with investments in wastewater treatment, benefiting 11 municipalities. It has been estimated that the amount invested in treatment is of BRL 120,852,842.33, which represents 38.9% of total sanitation resources for the state. The 13 wastewater treatment plants will provide an increase of 39,606.69 (x1,000 m³ year-1) of volume of treated sewage. The IN046 of eight municipalities might reach a value of 100.0% and the state of Espírito Santo might have its value changed from 27.0 to 46.9%, after the beginning of operation of these wastewater treatment plants.

Nanowastes treatment in environmental media

OBJECTIVES: This paper tried to review a recent research trend for the environmental exposure of engineered nanomaterials (ENMs) and its removal efficiency in the nanowaste treatment plants. METHODS: The studies on the predicted environmental concentrations (PEC) of ENMs obtained by exposure modeling and treatment (or removal) efficiency in nanowaste treatment facilities, such as wastewater treatment plant (WTP) and waste incineration plant (WIP) were investigated. The studies on the landfill of nanowastes also were investigated. RESULTS: The Swiss Federal Laboratories for Materials Science and Technology group has led the way in developing methods for estimating ENM production and emissions. The PEC values are available for surface water, wastewater treatment plant effluents, biosolids, sediments, soils, and air. Based on the PEC modeling, the major routes for the environmental exposure of the ENMs were found as WTP effluents/sludge. The ENMs entered in the WTP were 90-99% removed and accumulated in the activated sludge and sludge cake. Additionally, the waste ash released from the WIP contain ENMs. Ultimately, landfills are the likely final destination of the disposed sludge or discarded ENMs products. CONCLUSIONS: Although the removal efficiency of the ENMs using nanowaste treatment facilities is acceptable, the ENMs were accumulated on the sludge and then finally moved to the landfill. Therefore, the monitoring for the ENMs in the environment where the WTP effluent is discharged or biomass disposed is required to increase our knowledge on the fate and transport of the ENMs and to prevent the unintentional exposure (release) in the environment.

Fate of dissolved organic nitrogen during biological nutrient removal wastewater treatment processes.

Due to its potential to form toxic nitrogenous disinfection byproducts (N-DBPs), dissolved organic nitrogen (DON) is considered as one of the most important parameters in wastewater treatment plants (WWTP). This study describes a comprehensive investigation of variations in DON levels in orbal oxidation ditches. The results showed that DON increased gradually from 0.71 to 1.14 mg l-1 along anaerobic zone, anoxic zone, aerobic zone 1 and aerobic 2. Molecular weight fractionation of DON in one anaerobic zone and one aerobic zone (aerobic zone 2) was performed. We found that the proportion of small molecular weight (<6 kDa) decreased and large molecular weight (>20 kDa) showed opposite trend. This variation may have been caused due to the release of different types of soluble microbial products (SMPs) during biological processes. These SMPs contained both tryptophan protein-like and aromatic protein-like substances, which were confirmed by three-dimensional excitation-emission matrix (EEM) analysis.

Metagenomic analysis of cadmium and copper resistance genes in activated sludge of a tannery wastewater treatment plant.

In order to comprehensively characterize the copper and cadmium resistance in activated sludge of a tannery wastewater treatment plant, a resistance protein database of the two heavy metals was manually created by retrieving annotated sequences and related information from the public databases and published literatures. The metagenomic DNA was extracted from the activated sludge for Illumina high-throughput sequencing, and the obtained 11,973,394 clean reads (1.61 Gb) were compared against the established databases using BLAST tool. Annotations of the BLAST hits showed that 222 reads (0.019‰) and 197 reads (0.016‰) were identified as copper and cadmium resistance genes, respectively. Among the identified cadmium resistance genes, czcA encoding cobalt-zinc-cadmium resistance protein had the highest abundance (83 reads, 0.0069‰), which was further confirmed by annotation of the open reading frames predicted with the assembly contigs. Among the copper resistance genes, copA (66 reads, 0.0055‰) was most abundant, followed by copK and cusR. Alignment against the Clusters of Orthologous Groups (COG) database also suggested that 87.26% of the matched reads were grouped in COG0474 (cation transport ATPase). This study may be practically helpful for exploring various functional genes in the environment using high-throughput sequencing and bioinformatics methods.

Tratamento combinado de lixiviado de aterros de resíduos sólidos urbanos e esgoto doméstico como alternativa para a solução de um grave problema ambiental e de saúde pública - revisão bibliográfica. / Co-treatment of municipal solid waste landfill leachate and domestic wastewater as an alternative solution to a serious environmental and public health problem - a literature review.

A disposição de lixiviados de aterros de resíduos sólidos urbanos é um grande problema de saúde ambiental, com impactos sobre a saúde das populações que vivem em áreas circunvizinhas, devido às características poluentes deste lixiviado. Uma opção é coletar e direcionar o lixiviado para estações de tratamento de esgotos, nas quais podem ser tratados conjuntamente com o esgoto doméstico. A viabilidade dessa opção depende da existência de rede coletora de esgotos próxima ao aterro e da capacidade da estação de tratamento em assimilar as cargas, sobretudo orgânica e nitrogenada, advindas do lixiviado. Este trabalho apresenta uma revisão bibliográfica sobre o tratamento combinado de lixiviado e esgoto doméstico. Os estudos realizados mostram que a quantidade limite de lixiviado a ser recebida em estações de tratamento, sem comprometer a qualidade do efluente final, não é fixa, dada a grande variabilidade da composição dos lixiviados. Entretanto, a maioria dos estudos não apresenta variações significativas de qualidade para efluentes do tratamento combinado com até 2% de volume de lixiviado.

The disposal of municipal solid waste landfill leachates is a major environmental health problem, with impacts on the health of people living in surrounding areas due to the characteristics of leachate pollutants. One option is to collect and direct the leachate to sewage treatment plants, where it can be co-treated with domestic sewage. The viability of this option depends on the existence of sewerage near the landfill and the treatment plant capacity to absorb the loads, especially organic and nitrogen, stemming from leachate. This paper presents a literature review on combined treatment of leachate and domestic sewage. Studies show that the quantity limit of leachate to be received on treatment plants, without compromising the quality of the final effluent, is not fixed, given the great variability in the composition of leachate. However, most studies present no significant variations in quality for effluent treatment combined with up to 2% of the volume of leachate.

O emprego da análise de imagem na determinação da distribuição de tamanho de partículas da areia presente no esgoto sanitário / The use of image analysis to determine particle size distribution of grit carried by sewage

É consensual, no meio técnico, que unidades de desarenação devem reter partículas discretas de elevada velocidade relativa de sedimentação (por exemplo: areia, silte, cinzas, semente de frutas etc); e que desarenadores capazes de remover grãos de areia de tamanho maior ou igual a 0,2 mm removem a maior parte dos materiais que ocasionam problemas operacionais em estações de tratamento de esgoto (ETE). Entretanto, não existe concordância acerca da forma de se determinar a concentração ou a distribuição granulométrica de tais materiais no esgoto sanitário. O presente artigo apresenta um método para determinar a distribuição granulométrica da areia presente no esgoto sanitário, o qual se baseia no emprego de técnicas de análise de imagens digitais. A aplicação do método proposto demonstrou que, em média, 84 por cento da massa de areia carreada pelo esgoto sanitário afluente da ETE Jardim das Flores (Rio Claro, SP) era composta por partículas maiores ou iguais a 0,2 mm.

There is a consensus among technicians that degritters ought to remove discrete particles which present elevated settling velocities (e.g. sand, silt, ashes, fruit seeds etc.) and that units which are able to retain particles larger than or equal to 0.2 mm remove most of the material which causes operational problems to wastewater treatment plants (WWTP). Nevertheless, there is no agreement on how to determine grit concentration in wastewater and particle size distribution of this material. This paper presents a method to determine particle size distribution of grit carried by sewage based on the use of digital image analysis techniques. The use of the proposed method demonstrated that, on average, 84 percent of grit mass carried by the WWTP Jardim das Flores (Rio Claro, SP, Brazil) influent was made up of particles larger than or equal to 0.2 mm.

Microbiologia de sistema de lodos ativados e sua relação com o tratamento de efluentes industriais: a experiência da Cetrel / Activated sludge system microbiology and its relationship with the industrial effluents treatment: the experience of the Cetrel

Buscou-se, neste trabalho, caracterizar a comunidade microbiana de lodos ativados dos tanques de aeração (TA-2, TA-3 e TA-4) da estação de tratamento de efluentes (ETE) da Cetrel e correlacioná-la com parâmetros físico-químicos de processo, bem como avaliar o impacto do efluente industrial (EI) bruto na estrutura da comunidade do lodo. Adicionalmente, foi verificada a existência de possíveis correlações entre a qualidade do efluente tratado final (ETF) e a comunidade do lodo para identificar algum grupo biológico que pudesse ser usado como bioindicador desta ETE. Os principais grupos encontrados nos TA foram ciliados (livre natantes, de vida livre e pedunculados) e flagelados. Verificou-se que altas cargas de DBO e DQO no EI afetam negativamente o sistema, especialmente o grupo dos ciliados, que foram os melhores indicadores da elevada eficiência da ETE. O TA-2 mostrou ser o tanque mais estável e eficiente.

The purpose of this study was to characterize the microbial community of activated sludge in the aeration tanks (AT-2, AT-3 and AT-4) from the Cetrel wastewater treatment plant (WWTP) and to correlate it to physical-chemical parameters, as well as to assess the impact of the raw industrial effluent (IE) on the activated sludge community. Additionally, it was verified the relationship between the treated effluent (TE) quality and the biological groups to determinate indicators of the WWTP efficiency. Ciliated protozoa (free-swimming, crawler and sessile) and flagellates were the main biological groups found in the TA. It was demonstrated that high IE-BOD and -COD loads have a negative influence on the system, especially on the ciliated protozoa, which was the best indicator of high efficiency of the WWTP. The AT-2 was the more stable and efficient.