Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Más filtros










Intervalo de año de publicación
1.
Environ Pollut ; 290: 118049, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34479163

RESUMEN

Pharmaceutically active compounds are increasingly detected in raw and treated wastewater, surface water, and drinking water worldwide. These compounds can cause adverse effects to the ecosystem even at low concentrations and, to assess these impacts, toxicity tests are essential. However, the toxicity data are scarce for many PhACs, and when available, they are dispersed in the literature. The values of pharmaceuticals concentration in the environment and toxicity data are essential for measuring their environmental and human health risks. Thus this review verified the concentrations of pharmaceuticals in the aquatic environment and the toxicity related to them. The risk assessment was also carried out. Diclofenac, naproxen, erythromycin, roxithromycin, and 17ß-estradiol presented a high environment risk and 17α-ethinylestradiol presented a high human health risk. This shows the potential of these pharmaceuticals to cause adverse effects to the ecosystem and humans and establishes the necessity of their removal through advanced technologies.


Asunto(s)
Preparaciones Farmacéuticas , Contaminantes Químicos del Agua , Ecosistema , Monitoreo del Ambiente , Humanos , Medición de Riesgo , Aguas Residuales , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
2.
PLoS One ; 16(2): e0245834, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33561147

RESUMEN

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.


Asunto(s)
Hidrología/normas , Aprendizaje Automático , Modelos Estadísticos , Tecnología de Sensores Remotos , Brasil , Estándares de Referencia , Volatilización
3.
Chemosphere ; 268: 128778, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33143893

RESUMEN

This study was undertaken to assess the capacity of the upflow anaerobic sludge blanket (UASB) reactor, one of the most commonly used systems in Brazilian sewage treatment plants, to remove municipal sewage toxicity using different Danio rerio life stages (embryo, embryo-larval, larval, adult), and estrogenicity using in vitro (yeast Saccharomyces cerevisiae) and in vivo (vitellogenin induction in D. rerio) assays. Sensitivity of chronic fish assays were compared to the chronic Ceriodaphnia dubia assay. UASB-treated sewage met Brazilian legal limits for BOD and COD removals, but did not remove toxicity, and treated sewage remained extremely toxic to D. rerio larvae and C. dubia, and highly toxic to D. rerio embryos. The 4-day embryo assay had the same sensitivity as the adult acute toxicity assay, and could safely replace it, avoiding the need to sacrifice adult fish. No significant differences were identified in vitellogenin induction among organisms exposed to sewage or control. However, the in vitro test showed that anaerobic treatment increased sample estrogenicity from 27 to 40 ng equivalents of 17-ß estradiol per liter, a result corroborated by the greater induction of vitellogenin in male fish exposed to 5% (2.73 µg/g) and 20% (2.12 µg/g) treated sewage compared to the same concentrations of raw sewage (0.174 µg/g at 5% and 0.188 µg/g at 20%). Thus, UASB reactor should be followed by post-treatment to reduce risks of sewage discharge to receiving waters.


Asunto(s)
Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Anaerobiosis , Animales , Reactores Biológicos , Brasil , Estrona
4.
Environ Sci Pollut Res Int ; 26(5): 4260-4265, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30069777

RESUMEN

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%).


Asunto(s)
Colorantes/análisis , Industria Textil , Titanio/química , Rayos Ultravioleta , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Animales , Análisis de la Demanda Biológica de Oxígeno , Catálisis , Colorantes/toxicidad , Daphnia/efectos de los fármacos , Residuos Industriales/análisis , Oxidación-Reducción , Aguas Residuales/química , Contaminantes Químicos del Agua/toxicidad
5.
Ciênc. rural (Online) ; 49(1): e20180187, 2019. tab
Artículo en Inglés | LILACS | ID: biblio-1045224

RESUMEN

ABSTRACT: 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.


RESUMO: 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.

6.
Work ; 60(1): 41-47, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29733039

RESUMEN

BACKGROUND: The collective transportation system is essential to reduce the number of automobiles in the roads. Concerns exist related to quality, comfort and safety of bus driver's workstations. OBJECTIVE: The objective of this study was to improve the driver's workstation in the private collective transportation sector by analyzing ergonomic practices using the Ergonomic Work Analysis (EWA). The EWA was chosen because it seeks to evaluate the labor condition as it relates to the psychophysiological conditions of workers, it complies with regulatory standard 17 (NR17). METHODS: To identify driver concerns, interviews and questionnaires were administered. The workstation and worker routines were observed. RESULTS: The analysis revealed that the largest number of complaints related to noise, display light and location of the passenger identifier device. Drivers reported discomfort in the knees and lower back. CONCLUSION: Recommendations were made to improve the workstation and change the routine to minimize the discomfort and ergonomic risk factors.


Asunto(s)
Ergonomía/normas , Transportes/instrumentación , Conducción de Automóvil/normas , Brasil , Humanos , Sector Privado , Factores de Riesgo , Encuestas y Cuestionarios , Transportes/normas , Evaluación de Capacidad de Trabajo
7.
J Environ Manage ; 211: 154-163, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-29408063

RESUMEN

The objective of this study was to evaluate ADMI color removal from a biologically treated textile mill effluent by heterogeneous photocatalysis with UV-visible irradiation (UV-vis) using a novel catalyst composed of TiO2 supported on hydrotalcite and doped with iron oxide (HT/Fe/TiO2). 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 TiO2 and HT/Fe/TiO2 of Fe:Ti molar ratios of 0.25, 0.5, 0.75 and 1, with varying catalyst doses (0-3 mg/L), initial pH values (4-10) and UV-vis times (0-6 h). The highest ADMI color removal with unmodified TiO2 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/TiO2 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 TiO2, 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/TiO2 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 UV-vis, because of the low initial COD (78 mg/L). Secondary effluent toxicity to Daphnia similis (EC50 = 70.7%) was reduced by photocatalysis with TiO2 (EC50 = 95.0%) and the HT/Fe/TiO2 1 composite (EC50 = 78.6%). HT/Fe/TiO2 1 was reused five times and still lowered secondary effluent ADMI color below local discharge limits. Benefits of the HT/Fe/TiO2 1 catalyst compared to TiO2 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.


Asunto(s)
Hidróxido de Aluminio , Hidróxido de Magnesio , Industria Textil , Titanio , Purificación del Agua , Catálisis , Compuestos Férricos , Eliminación de Residuos Líquidos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...