Remoção de micropoluentes orgânicos e atividade estrogênica de esgoto doméstico em um biorreator osmótico anaeróbio acoplado à destilação com membranas

The contamination of water sources by pharmaceutically active compounds (PhACs) and their effect on aquatic communities and human health have become an environmental concern worldwide. Municipal sewage is the major source of organic micropollutants in the environment. Even when there is a sewage treatment plant present, conventional biological treatment cannot remove recalcitrant compounds. Membrane bioreactors (MBRs), due to their high solids concentrations and retention times, improve biological treatment removal of nutrients and recalcitrant organic compounds. Forward osmosis (FO) and membrane distillation (MD), which present high rejection of dissolved compounds, even at concentrations of µg L -1 and ng L -1 , are an alternative for use in MBRs treating municipal sewage. Thus, this research aimed to evaluate the performance of an anaerobic osmotic membrane bioreactor coupled with membrane distillation (AnOMBR-MD) in treatment of municipal sewage containing PhACs (17α- ethinylestradiol, betamethasone, ketoprofen, fenofibrate, fluconazole, loratadine e prednisone). The AnOMBR-MD was operated with NaCl as draw solute in a hybrid submerged FO-MD module. The removal efficiencies of dissolved organic carbon (DOC) and P-PO 43- were 97.2% and 98.0%. N-NH 4+ accumulated in the bioreactor and reached the draw solution (DS) and distillate. Changes in the microbial community were observed due to salinity build-up and the presence of PhACs, while the system removed more than 96.4% of the compounds evaluated. Estrogenic activity was not detected in distillate samples and the environmental and human health risks sharply declined. A second study was conducted to select the best DS salt in the integrated FO-MD hybrid module. The technique to order preference by similarity to the ideal solution was used in in multicriteria decision making, that considered results of water and salt flux, energy consumption, costs, and FO and global rejection of micropollutants for each draw solute tested (NaCl, MgCl 2 , sodium acetate (NaOAc), magnesium acetate (MgOAc 2 ), and EDTA-Na 2 ). MgCl 2 was selected as the best salt for the DS in the FO-MD system and could be used to mitigate salinity build-up in the mixed liquor, followed in order of rank by NaCl, NaOAc, EDTA-Na 2 and MgOAc 2 . In the third study, MgCl 2 was used as draw solute of the AnOMBR-MD in treatment of synthetic municipal sewage containing PhACs and estrogenic activity. Due to organic and inorganic fouling, permeate fluxes declined 82 and 67%, for FO and MD, respectively. MD salt rejection was higher than 99.6% and more than 90% of dissolved organic carbon was removed. P-PO 43- rejection by the FO-MD module was greater than 99.98%, which led to accumulation of this nutrient in the mixed liquor (ML). N-NH 4+ concentration in the ML also increased, and with the reverse flux of Mg 2+ , precipitation of struvite, magnesite and monetite may have occurred. Salinity build-up was lower than when NaCl was used as DS. The ML conductivity increased until day 21 and then stabilized. Biological removal of estrogenic activity was reduced with salt accumulation, but increased after salinity stabilization. AnOMBR-MD removal of estrogenic activity was higher than 99.97%, with reduction in environmental and non-carcinogenic human risks from high to low, while incremental lifetime carcinogenic risk decreased to negligible. On the other hand, risk assessment showed that a better removal of ketoprofen and loratadine is needed, since the acute environmental risk of the distillate was still high, due to the presence of these substances. The results of the present research demonstrated that permeate fluxes in FO and MD are still low and some strategies to overcome this drawback are needed, such as physical and chemical cleaning. Furthermore, the use of the YES assay combined with detection and identification of micropollutants allowed an effective assessment of overall treatment performance. Keywords: Microbial community. Concentration polarization. Reverse salt flux. YES assay. Risk assessment.A contaminação dos recursos hídricos por fármacos (PhACs) e os seus efeitos em organismos aquáticos e aos seres humanos tornou-se um problema de grande preocupação ambiental. Esgotos domésticos são a principal fonte de micropoluentes orgânicos para o meio ambiente. Mesmo quando existem estações de tratamento de esgotos, o tratamento biológico convencional não é capaz de remover compostos recalcitrantes. Biorreatores com membranas (MBRs), por permitirem elevada concentração de sólidos e maior tempo de residência celular, apresentam maior eficiência na remoção de nutrientes e compostos orgânicos recalcitrantes. O uso de membranas de osmose direta (FO) e de destilação (MD), que apresentam elevada rejeição de compostos dissolvidos, mesmo em concentrações de µg L -1 e ng L -1 , pode ser uma alternativa para MBRs no tratamento de esgoto doméstico. Desta forma, esta pesquisa teve como objetivo avaliar o desempenho de um biorreator osmótico anaeróbio acoplado à destilação com membranas (AnOMBR-MD) no tratamento de esgoto doméstico contendo PhACs (17α- etinilestradiol, betametasona, cetoprofeno, fenofibrato, fluconazol, loratadina e prednisona). O AnOMBR-MD foi operado utilizando NaCl como o soluto da solução osmótica (DS) do módulo híbrido submerso de FO-MD. A eficiência de remoção de carbono orgânico dissolvido (DOC) e P-PO 43- foi de 97,2% e 98,0%. Em relação ao N-NH 4+ , foi observado o acúmulo no biorreator, atingindo a DS e o destilado. Mudanças na comunidade microbiana foram observadas devido ao acúmulo de salinidade e à presença de PhACs, enquanto o sistema removeu mais de 96,4% dos compostos avaliados. A atividade estrogênica não foi detectada em amostras de destilados e os riscos ambientais e para a saúde humana foram reduzidos. Um segundo estudo foi conduzido para selecionar o melhor soluto para a DS no módulo híbrido de FO-MD. A técnica para avaliar o desempenho das alternativas através da similaridade com a solução ideal foi utilizada para auxiliar na tomada de decisão, considerando os resultados de fluxo de água e sal, consumo de energia, custos e rejeição na FO e global de micropoluentes, para cada soluto testado (NaCl, MgCl 2 , acetato de sódio (NaOAc), acetato de magnésio (MgOAc 2 ) e EDTA- Na 2 ). O MgCl 2 foi selecionado como o melhor sal para o sistema de FO-MD e pode ser usado para mitigar o acúmulo de salinidade no líquido reacional, seguido em ordem de classificação por NaCl, NaOAc, EDTA-Na 2 e MgOAc 2 . No terceiro estudo, MgCl 2 foi utilizado para compor a DS do AnOMBR-MD no tratamento de esgoto doméstico sintético, contendo PhACs e atividade estrogênica. Devido à incrustação orgânica e inorgânica, os fluxos de permeado reduziram 82 e 67%, para FO e MD, respectivamente. A rejeição do sal pela MD foi superior a 99,6% e mais de 90% do carbono orgânico dissolvido foi removido. A rejeição de P-PO 43- pelo módulo FO-MD foi superior a 99,98%, o que promoveu o acúmulo desse nutriente no líquido reacional (ML). A concentração de N-NH 4+ no ML também aumentou, e com o fluxo inverso de sal de Mg 2+ , pode ter ocorrido a precipitação de estruvita, magnesita e monetita. O acúmulo de salinidade foi menor do que na operação com NaCl. A condutividade do ML aumentou até o dia 21 e depois se estabilizou. A remoção biológica de atividade estrogênica diminuiu com o acúmulo de sal, mas aumentou novamente após a estabilização da salinidade. A remoção da atividade estrogênica pelo AnOMBR-MD foi superior a 99,97%, o que levou à redução nos riscos ambiental e humano não carcinogênico de alto para baixo, enquanto o incremento de risco carcinogênico ao longo da vida diminuiu para desprezível. Por outro lado, a avaliação de risco mostrou que uma melhor remoção de cetoprofeno e loratadina é necessária, uma vez que o risco ambiental agudo do destilado ainda era alto, devido à presença desses fármacos. Os resultados da presente pesquisa demonstraram que os fluxos de permeado em FO e MD ainda são baixos e algumas estratégias para contornar esta desvantagem são necessárias, como limpeza física e, ou química. Além disso, o uso do ensaio YES combinado com a detecção e identificação de micropoluentes permitiu uma avaliação eficaz do desempenho geral do tratamento. Palavras-chave: Comunidade microbiana. Polarização da concentração. Fluxo inverso de sal. Ensaio YES. Avaliação de risco

Heterogeneous photocatalysis using TiO2 modified with hydrotalcite and iron oxide for color and toxicity removal from biologically treated textile mill effluent

O objetivo deste trabalho foi avaliar a remoção de cor ADMI de um efluente têxtil secundário pela fotocatálise heterogênea com TiO2 modificado com hidrotalcita e óxido de ferro (HT/Fe/TiO2), sob radiação UV-visível. Nos testes de simulação de tratamento biológico, os corantes reativos utilizados na indústria têxtil não foram biodegradados, mesmo após 96 h, enquanto houve mais que 50% de remoção dos corantes a cuba, o que indica que o efluente secundário ainda continha muitos corantes reativos aniônicos. A fotocatálise foi realizada com TiO2 e HT/Fe/TiO2 (razão molar Fe:Ti de 1:4, 2:4, 3:4 e 4:4) e diferentes concentrações do catalisador (0 - 3 mg/L), valores de pH (4 -10) e tempos de radiação UV-visível (0 - 6 h). A maior remoção de cor ADMI com TiO2 foi encontrada em pH 4, com 2 g/L do catalisador. O compósito mais eficiente foi o HT/Fe/TiO2 4:4, em pH 10, sendo inclusive melhor que TiO2, com eficiências de remoção de 96% e 88% de cor ADMI, respectivamente, após 6 h de radiação UV- visível e 2 g/L do catalisador. Para HT/Fe/TiO2 4:4, cuja energia de bandgap foi de 2,34 eV, o pH 10 foi melhor para a fotocatálise, porque nesse pH a produção de radicais hidroxila foi favorecida, devido à maior concentração de OH- e foi demonstrado em teste com adição de 2-propanol, um sequestrador de .OH, que o mecanismo de degradação foi por radicais hidroxila. A remoção de DQO foi de cerca de 20% para TiO2 e HT/Fe/TiO2 4:4, após 6 h sob radiação UV-visível. Após a fotocatálise, a toxicidade aguda moderada do efluente secundário (CE50 = 70,7%) foi reduzida, mais com TiO2 (CE50 = 95,0 %) do que com o compósito HT/Fe/TiO2 4:4 (CE50 = 78,6 %). A fotocatálise heterogênea com HT/Fe/TiO2 mostrou-se adequada como pós tratamento por prover elevada eficiência de remoção de cor ADMI e remoção adicional de DQO e toxicidade e, devido ao caráter magnético do catalisador, reduziria custos quanto à sua recuperação se comparado ao TiO2.The objective of this study was to evaluate ADMI color removal from a biologically treated textile mill effluent by heterogeneous photocatalysis using TiO2 modified with hydrotalcite and iron oxide (HT/Fe/TiO2) under UV-visible radiation. Simulated biological treatment of solutions of the dyes (50 mg/L) used in the greatest amounts at the mill where the effluent was collected, resulted in no color removal in the reactive dye solutions and about 50% color removal in vat dye solutions, after 96 hours, indicating that the secondary effluent contained a large proportion of anionic reactive dyes. Photocatalytic treatments were carried out with TiO2 and HT/Fe/TiO2 (Fe:Ti molar ratios of 1:4, 2:4, 3:4 and 4:4), with varying catalyst concentration (0 - 3 mg/L), pH (4 - 10) and UV-visible irradiation time (0 - 6 h). The highest ADMI color removal with unmodified TiO2 alone was found at pH 4 and 2 g/L of the catalyst. The most efficient composite was HT/Fe/TiO2 4:4, at pH 10, and this composite provided more complete ADMI color removal (96%) than unmodified TiO2 (88%), after 6 h under UV- visible irradiation, with 2 g/L of catalyst. For HT/Fe/TiO2 4:4,with bandgap energy equal to 2.34 eV, pH 10 was better since hydroxyl radical formation was favored because of the higher concentration of hydroxide ions present in solution and hydroxyl radicals were shown to be responsible for the color reduction, since when 2-propanol, an .OH scavenger, was added, color removal was very low. COD removal was similar, approximately 20% for both catalysts after 6 h under UV-visible irradiation. Secondary effluent toxicity to Daphnia similis (EC50 = 70.7%) decreased more after photocatalysis with TiO2 (EC50 = 95.0%) than with the HT/Fe/TiO2 4:4 composite (EC50 = 78.6%). The HT/Fe/TiO2 4:4 composite catalyst proved efficient in tertiary treatment of textile mill effluent for ADMI color removal and toxicity reduction and its magnetic nature facilitated its recovery compared to TiO2, which would reduce treatment costs.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

ADMI color and toxicity reductions in raw textile mill effluent and dye mixtures by TiO2/UV is limited by presence of vat dyes

Full-scale application of heterogeneous photocatalysis for industrial wastewater treatment remains a challenge because of the complex nature of these matrices and the potential to form toxic by-products during treatment. A recent unsuccessful attempt to find adequate conditions for TiO2/UV treatment of a cotton dyeing textile mill led to this study on the treatability of mixtures of the dyes used in the greatest amounts at the mill and therefore most likely to be present in mill effluent. Four reactive and three vat dyes were mixed in different combinations and treated (10 mg/L of each dye, 0.5 mg/L TiO2, pH 4) to evaluate the influence of the different dyes on ADMI color, chemical oxygen demand (COD), and acute toxicity. While ADMI color removal was similar in all dye mixtures, COD removal was higher when vat dyes were absent. When treated individually, vat dyes exhibited greater recalcitrance, with no ADMI color removal and COD removals of less than 30%. Toxicity to Daphnia similis was decreased or eliminated from dye mixtures that exhibited the highest COD removals and corresponded to those in which reactive dyes were partially degraded. For raw textile mill effluent, photocatalysis reduced but did not eliminate treated effluent toxicity (EC50 = 26.8%)

Heterogeneous photocatalysis using TiO2 modified with hydrotalcite and iron oxide under UV–visible irradiation for color and toxicity reduction in secondary textile mill effluent

The objective of this study was to evaluate ADMI color removal from a biologically treated textile mill effluent by heterogeneous photocatalysis with UVevisible irradiation (UVevis) using a novel catalyst composed of TiO 2 supported on hydrotalcite and doped with iron oxide (HT/Fe/TiO 2 ). Simulated biological treatment of solutions of the dyes (50 mg/L) used in the greatest amounts at the mill where the textile effluent was collected resulted in no color removal in reactive dye solutions and about 50% color removal in vat dye solutions, after 96 h, indicating that the secondary effluent still contained a large proportion of anionic reactive dyes. Photocatalytic treatments were carried out with TiO 2 and HT/Fe/TiO 2 of Fe:Ti molar ratios of 0.25, 0.5, 0.75 and 1, with varying catalyst doses (0e3 mg/L), initial pH values (4 e10) and UVevis times (0e6 h). The highest ADMI color removal with unmodified TiO 2 was found at a dose of 2 g/L and pH 4, an impractical pH value for industrial application. The most efficient composite was HT/Fe/TiO 2 1 at pH 10, also at a dose of 2 g/L, which provided more complete ADMI color removal, from 303 to 9 ADMI color units (96%), than unmodified TiO 2 , from 303 to 37 ADMI color units (88%), under the same conditions. Hydroxyl radicals were responsible for the color reduction, since when 2- propanol, an OH scavenger, was added color removal was very low. For this reason, the HT/Fe/TiO 2 1 composite performed better at pH 10, because the higher concentration of hydroxide ions present at higher pH favored hydroxyl radical formation. COD reductions were relatively low and similar, approximately 20% for both catalysts after 6 h under UVevis, because of the low initial COD (78 mg/L). Secondary effluent toxicity to Daphnia similis (EC 50 1⁄4 70.7%) was reduced by photocatalysis with TiO 2 (EC 50 1⁄4 95.0%) and the HT/Fe/TiO 2 1 composite (EC 50 1⁄4 78.6%). HT/Fe/TiO 2 1 was reused five times and still lowered secondary effluent ADMI color below local discharge limits. Benefits of the HT/Fe/TiO 2 1 catalyst compared to TiO 2 include its lower bandgap energy (2.34 eV vs 3.25 eV), higher ADMI color removal and its magnetic nature that facilitated its recovery and would reduce treatment costs

Reference evapotranspiration of Brazil modeled with machine learning techniques and remote sensing.

Reference evapotranspiration (ETo) is a fundamental parameter for hydrological studies and irrigation management. The Penman-Monteith method is the standard to estimate ETo and requires several meteorological elements. In developing countries, the number of weather stations is insufficient. Thus, free products of remote sensing with evapotranspiration information must be used for this purpose. In this context, the objective of this study was to estimate monthly ETo from potential evapotranspiration (PET) made available by MOD16 product. In this study, the monthly ETo estimated by Penman-Monteith method was considered as the standard. For this, data from 265 weather station of the National Institute of Meteorology (INMET), spread all over the Brazilian territory, were acquired for the period from 2000 to 2014 (15 years). For these months, monthly PET values from MOD16 product for all Brazil were also downloaded. By using machine learning algorithms and information from WorldClim as covariates, ETo was estimated through images from the MOD16 product. To perform the modeling of ETo, eight regression algorithms were tested: multiple linear regression; random forest; cubist; partial least squares; principal components regression; adaptive forward-backward greedy; generalized boosted regression and generalized linear model by likelihood-based boosting. Data from 2000 to 2012 (13 years) were used for training and data of 2013 and 2014 (2 years) were used to test the models. The PET made available by the MOD16 product showed higher values than those of ETo for different periods and climatic regions of Brazil. However, the MOD16 product showed good correlation with ETo, indicating that it can be used in ETo estimation. All models of machine learning were effective in improving the performance of the metrics evaluated. Cubist was the model that presented the best metrics for r2 (0.91), NSE (0.90) and nRMSE (8.54%) and should be preferred for ETo prediction. MOD16 product is recommended to be used to predict monthly ETo, which opens possibilities for its use in several other studies

Increasing yoghurt daily production with modeling and simulation process

The objective of this research was to use the modeling and computer simulation to support decision makers, aiming to increase the productive capacity of the agro-industry of LaticínioFunarbe. Specifically, it has modeled the current yoghurt production sector for simulation that enables it to meet the new demand. The Arena 14.7 simulation software was used to conduct the modeling. To validate the model, the output of yoghurt production collected at the factory for three months was compared with the output from the simulated computational model. Two indicators were established to perform analyzes of four different scenarios. The implemented model resulted in an increase in the production capacity of 5,000L.d^-1 of yoghurt, corresponding to a production of yoghurts processed daily three times higher than the current production.O objetivo deste trabalho foi usar a modelagem e a simulação computacional como ferramenta de suporte aos tomadores de decisão, visando a aumentar a produtividade da agroindústria Laticínio Funarbe. Especificamente, modelou o setor atual da produção de iogurte para elaboração de análises que possibilita atender à nova demanda. Para a modelagem utilizou-se o software de simulação Arena 14.7. Para a validação do modelo foram comparados os resultados de produção de iogurte coletados na fábrica durante três meses com os resultados simulados pelo modelo computacional. Foram estabelecidos dois indicadores para realizar análises de quatro cenários diferentes. Por meio do modelo implementado, obtivemos um aumento da capacidade produtiva de 5000L.d^-1 de iogurte, que corresponde a uma produção de iogurtes processados, diariamente, três vezes maior do que a produção atual

ADMI color and toxicity reductions in raw textile mill effluent and dye mixtures by TiO2/UV is limited by presence of vat dyes

Full-scale application of heterogeneous photocatalysis for industrial wastewater treatment remains a challenge because of the complex nature of these matrices and the potential to form toxic by-products during treatment. A recent unsuccessful attempt to find adequate conditions for TiO2/UV treatment of a cotton dyeing textile mill led to this study on the treatability of mixtures of the dyes used in the greatest amounts at the mill and therefore most likely to be present in mill effluent. Four reactive and three vat dyes were mixed in different combinations and treated (10 mg/L of each dye, 0.5 mg/L TiO2, pH 4) to evaluate the influence of the different dyes on ADMI color, chemical oxygen demand (COD), and acute toxicity. While ADMI color removal was similar in all dye mixtures, COD removal was higher when vat dyes were absent. When treated individually, vat dyes exhibited greater recalcitrance, with no ADMI color removal and COD removals of less than 30%. Toxicity to Daphnia similis was decreased or eliminated from dye mixtures that exhibited the highest COD removals and corresponded to those in which reactive dyes were partially degraded. For raw textile mill effluent, photocatalysis reduced but did not eliminate treated effluent toxicity (EC50 = 26.8%)