Removal of reduced forms of sulfur, iron and manganese from water by nanofiltration membrane separation

Diversas regiones presentan problemas de calidad de sus aguas para abastecimiento. En algunas ocasiones, el sistema de distribución de agua ha sufrido de episodios de proliferación de características indeseables de color, sabor y olor, además del incremento de los reclamos por parte de los consumidores. Por tales razones ha aumentado la desconfianza del consumidor y el consumo de agua embotellada. Es bien sabido que entre los principales compuestos que causan sabor, olor y color en el agua se encuentran el hierro (Fe+2), el manganeso (Mn+2) y el sulfuro de hidrógeno (H2S). En esta investigación fue usada una planta piloto de nanofiltración abastecida con agua bruta proveniente de una represa que suministra agua para una Planta de Tratamiento de Agua Potable de la ciudad de Porto Alegre en Brasil. Este proceso mostró ser efectivo en la remoción de los compuestos de estudio utilizando las condiciones operacionales escogidas.Many regions are affected by quality problems in their water sources’ supplies. Sometimes, the distributed drinking water may have problems associated with the presence of compounds that cause color, taste and odor leading to growing consumer’s complaints, mistrust, and increasing consumption of bottled water. It is well known that hydrogen sulfide (H2S), iron (Fe+2) and manganese (Mn+2) cause taste, odor and color in drinking water. This research used a pilot plant nanomembrane filtration system to investigate the removal of those compounds from water. The pilot plant was supplied with raw water taken from a reservoir used as water source for a treatment plant of the city of Porto Alegre, Brazil. The measurements demonstrated that nanomembrane filtration was effective in the removal of iron, manganese and hydrogen sulfide from water, for the operational conditions tested in the investigation

Multi-antibiotic resistant bacteria in landfill bioaerosols: environmental conditions and biological risk assessment

Landfills, as well as other waste management facilities are well-known bioaerosols sources. These places may foment antibiotic-resistance in bacterial bioaerosol (A.R.B.) due to inadequate pharmaceutical waste disposal. This issue may foster the necessity of using last-generation antibiotics with extra costs in the health care system, and deaths. The aim of this study was to reveal the multi-antibiotic resistant bacterial bioaerosol emitted by a sanitary landfill and the surrounding area. We evaluated the influence of environmental conditions in the occurrence of A.R.B. and biological risk assessment. Antibiotic resistance found in the bacteria aerosols was compared with the AWaRE consumption classification. We used the BIOGAVAL method to assess the workers' occupational exposure to antibiotic-resistant bacterial bioaerosols in the landfill. This study confirmed the multi-antibiotic resistant in bacterial bioaerosol in a landfill and in the surrounding area. Obtained mean concentrations of bacterial bioaerosols, as well as antibiotic-resistant in bacterial bioaerosol (A.R.B.), were high, especially for fine particles that may be a threat for human health. Results suggest the possible risk of antibiotic-resistance interchange between pathogenic and non-pathogenic species in the landfill facilities, thus promoting antibiotic multi-resistance genes spreading into the environment

Exposure to polycyclic aromatic hydrocarbons in atmospheric PM1.0 of urban environments: Carcinogenic and mutagenic respiratory health risk by age groups

We investigated the carcinogenic and mutagenic respiratory health risks related to the exposure to atmospheric PAHs in an urban area. Our study focused in the association of these pollutants and their possible effect in human health, principally respiratory and circulatory diseases. Also, we determined a relationship between the inhalation risk of PAHs and meteorological conditions. We validated the hypothesis that in winter PAHs with high molecular weight associated to submicron particles (PM1) may increase exposure risk, especially for respiratory diseases, bronchitis and pneumonia diseases. Moreover, in our study we verified the relationship between diseases and several carcinogenic PAHs (Ind, BbkF, DahA, BaP, and BghiP). These individual PAHs contributed the most to the potential risk of exposure for inhalation of PM1.0. Even at lower ambient concentrations of BaP and DahA in comparison with individual concentrations of other PAHs associated to PM1.0. Mainly, research suggests to include carcinogenic and mutagenic PAHs in future studies of environmental health risk due to their capacity to associate to PM10. Such carcinogenic and mutagenic PAHs are likely to provide the majority of the human exposure, since they originate from dense traffic urban areas were humans congregate

Assessment of the NO2 distribution and relationship with traffic load in the Caribbean coastal city

NO2 ambient concentrations were measured in a coastal Caribbean city. Barranquilla is a Caribbean city located in the North of Colombia that has approximately 1.200.000 inhabitants and possesses a warm, humid climate. In order to obtain the concentration of the contaminant in an adequate resolution, 137 passive diffusion tubes from Gradko© were installed. Diffusion passive tubes prepared with 20% TEA/water were located at the roadside between 1 and 5 m from the kerb edge. The sampling period was two weeks, from 3/16/2019 to 3/30/2019. Samples were analyzed on the UV CARY1 spectrophotometer by Gradko©. Results showed an average of 19.92 ±11.50 µg/m3 , with a maximum and minimum value of 70.27 and 0.57 µg/m3 , respectively. Spatial NO2 correlation with low traffic load was higher than with maximum traffic. The expected results include analyzing the areas of the city with high concentrations of this pollutant that exceed the WHO guidelines in six (6) points. Overall, the multiregression analysis is a very effective method to enrich the understanding of NO2 distributions. It can provide scientific evidence for the relationship between NO2 and traffic, beneficial for developing the targeted policies and measures to reduce NO2 pollution levels in hot spots. This research may subsidize knowledge to serve as a tool for environmental and health authorities

Indoor-outdoor relationships of airborne nanoparticles, BC and VOCs at rural and urban preschools

Health risks caused by exposure to black carbon (BC) and nanoparticles (NP) are well studied, although no standard currently exists for them worldwide. Exposure to children may lead to serious health effects due to their increased vulnerability and longer time spend inside the classrooms, making it important to assess the factors that affect air quality in preschools. Thus, this work aims to evaluate indoor-outdoor (I/O) relationships of NPs in the 10–420 nm range, BC and volatile organic compounds (VOCs) at rural and urban preschools (aged 3–5 years) between May 2016 and July 2017. Factorial analysis was applied to identify the possible emission sources. Prior communalities were estimated by the squared multiple correlations with all other variables. We used the varimax rotation method and the criterion for factor selection was the number of eigenvalues greater than one. Results indicate that BC and NP were 4- and 3.2-times higher in urban outdoor caused by traffic emissions, respectively. Highest concentrations occurred during rush hours and during the pickup time of children. In urban school, BC was directly related to accumulation mode (N49-205), while in the rural area, BC was related to local traffic and particles from pulp industries in the regional background. Nucleation mode (N11-36) was related to traffic emissions in urban school, while in the rural school was related with secondary formation of particles. Mean I/O ratios of BC and NP in the urban (0.54; 0.51) and rural (0.71; 0.91) schools, respectively, suggested that their higher concentrations occurred in outdoors. VOCs were higher indoor in urban (I/O = 1.97) and rural (I/O = 2.22) sites, indicating these pollutants are generated inside, regardless of urban or rural sites. These findings suggest the necessity of improving ventilation and commuting styles to lower the exposure of children to air pollutants in and around school environments

Evaluación de la presencia de bioaerosoles en una unidad de cuidados intensivos neonatales

En este estudio se evaluaron la inmisión de los bioaerosoles bacterianos en las diferentes del sistema respiratorio en una unidad de cuidados intensivos neonatales (UCI). En este estudio, se utilizó un impactador Andersen de seis etapas para el muestreo de bioaerosoles con un caudal de 28,3 L/min. Las concentraciones obtenidas de bioaerosoles bacterianos oscilaron entre 67 y 423 UFC/m3, con un valor promedio de 110,13 UFC/m3, lo que puede representar una posible amenaza para la salud de los trabajadores y los neonatos en la UCI. Los resultados indicaron que Staphylococcus saprophyticus y Staphylococcus epidermidis habían predominado, especialmente en la quinta y sexta etapa, lo que significa segundos bronquios y alvéolos. Mientras que Staphylococcus fue el género de mayor prevalencia, Alloiococcus otitidis, Bacillus subtiles, Bacillus thuringiensis, Kocuria rosea y Pseudomonas pseudoalcaligene se presentaron en los alvéolo

Antibiotic resistance of airborne viable bacteria and size distribution in neonatal intensive care units

Despite their significant impact on public health, antibiotic resistance and size distributions of airborne viable bacteria in indoor environments in neonatal intensive care units (NICU) remain understudied. Therefore, the objective of this study was to assess the antibiotic resistance of airborne viable bacteria for different sizes (0.65–7 µm) in private-style and public-style neonatal intensive care units (NICU). Airborne bacteria concentrations were assessed by a six-stage Andersen impactor, operating at 28.3 L/min. Public-style NICU revealed higher concentrations of airborne viable bacteria (53.00 to 214.37 CFU/m3) than private-style NICU (151.94–466.43), indicating a possible threat to health. In the public-style NICU, Staphylococcus was the highest bacterial genera identified in the present study, were Staphylococcus saprophyticus and Staphylococcus epidermidis predominated, especially in the second bronchi and alveoli size ranges. Alloiococcus otitidis, Bacillus subtiles, Bacillus thuringiensis, Kocuria rosea, and Pseudomonas pseudoalcaligene, were identified in the alveoli size range. In NICU#2, eight species were identified in the alveoli size range: Bacillus cereus, Bacillus subtilis, Bacillus thuringiensis, Eikenella corrodens, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus gordoni. Multi-drug-resistant organisms (MDROs) were found in both of the NICUs. Bacillus cereus strains were resistant to Ampicillin, Cefoxitin, Ceftaroline, and Penicillin G. Staphylococcus cohnii ssp. cohnii was resistant in parallel to ampicillin and G penicillin. Staphylococcus saprophyticus strains were resistant to Ampicillin, Penicillin G, Oxaxilin, and Erythromycin. Results may indicate a potential threat to human health due to the airborne bacteria concentration and their antibiotic resistance ability. The results may provide evidence for the need of interventions to reduce indoor airborne particle concentrations and their transfer to premature infants with underdeveloped immune systems, even though protocols for visitors and cleaning are well-established

Coal emissions adverse human health effects associated with ultrafine/nano-particles role and resultant engineering controls

There are multiple elements which enable coal geochemistry: (1) boiler and pollution control system design parameters, (2) temperature of flue gas at collection point, (3) feed coal and also other fuels like petroleum coke, tires and biomass geochemistry and (4) fuel feed particle size distribution homogeneity distribution, maintenance of pulverisers, etc. Even though there is a large number of hazardous element pollutants in the coal-processing industry, investigations on micrometer and nanometer-sized particles including their aqueous colloids formation reactions and their behaviour entering the environment are relatively few in numbers. X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/ (Energy Dispersive Spectroscopy) EDS/ (selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM)/EDS and granulometric distribution analysis were used as an integrated characterization techniques tool box to determine both geochemistry and nanomineralogy for coal fly ashes (CFAs) from Brazil´s largest coal power plant. Ultrafine/nano-particles size distribution from coal combustion emissions was estimated during the tests. In addition the iron and silicon content was determined as 54.6% of the total 390 different particles observed by electron bean, results aimed that these two particles represent major minerals in the environment particles normally. These data may help in future investigations to asses human health actions related with nano-particles

Remoção de sulfeto de hidrogênio, ferro e manganês de águas de abastecimento através dos processos de dessorção gasosa, nanofiltração e oxidação com permanganato de potássio

Inúmeras regiões brasileiras apresentam problemas qualitativos em seus mananciais de abastecimento, originando dificuldades para a potabilização da água distribuída nas cidades. Geralmente, os consumidores julgam a segurança da água potável que bebem através de seus sentidos organolépticos. Os processos convencionais utilizados nas estações de tratamento de água não são efetivos na remoção de muitos compostos que causam cor, gosto e odor na água. Devido a isto, é comum que as companhias de saneamento recebam reclamações por parte dos consumidores sobre a qualidade da água distribuída. Dentre os compostos que causam gosto, odor e cor na água encontram-se o sulfeto de hidrogênio, o ferro e o manganês. O sulfeto gera um odor de “ovo podre”, perceptível a concentrações que variam entre 0,05 e 0,1 mg·L-1. Manganês e ferro estão associados principalmente a produção de cor e precipitados na água. Desta forma, o objetivo da pesquisa proposta foi estudar técnicas de tratamento alternativas as convencionais para controlar gosto, cor e odor na água potável pela presença de sulfeto de hidrogênio, ferro e manganês. Os processos investigados foram aeração em torre de dessorção, nanofiltração em membrana e oxidação com permanganato de potássio. Os testes foram realizados com água bruta oriunda do reservatório da Lomba do Sabão, em Porto Alegre. Os ensaios de oxidação anteriormente à clarificação físico-química constaram de 4 etapas. Na primeira, foram testados o cloreto férrico e o sulfato de alumínio, possibilitando a elaboração de diagramas de coagulação. Na segunda etapa, foi calculada a eficiência da coagulação na remoção de Fe(II), Mn(II) e H2S. Na terceira etapa, foi calculada a demanda do oxidante na água. Finalmente, na quarta etapa realizaram-se ensaios de oxidação do permanganato associado à clarificação físico-química. Os resultados mostraram que o processo de coagulação conseguiu remover o ferro satisfatoriamente, mas não o manganês. Nos ensaios usando permanganato os resultados mostraram que as remoções de ferro, manganês e sulfeto de hidrogênio foram de 92%; 59% e 94% (pH 7), e 93%; 74% e 100% (pH 8,0), respectivamente. No caso da relação estequiométrica, as reduções foram maiores quando foi usada a relação estequiométrica de 1,0 e pH 8,0 (89% para Mn e 95% para Fe). O protótipo de torre de dessorção, localizado na ETA Lomba do Sabão, foi operado com razões ar:água de 8 e 12 m3:m3. As remoções de ferro variaram entre 14% a 31%; para manganês, não houve redução aparente. As concentrações efluentes de sulfeto de hidrogênio foram inferiores ao limite de detecção do método analítico, mostrando que houve volatilização do gás neste processo. O protótipo do sistema de membranas de nanofiltração foi também instalado na ETA Lomba do Sabão. Foram realizados ensaios com vazões de 2 e 4 L∙min-1, correspondentes a taxas de aplicação de 14 e 28 L∙h-1∙m-2 a 25°C. As rejeições da membrana para a taxa de 14 L∙h-1∙m-2 foram de 91%, 96% e 100% (<LD) para ferro, manganês e sulfeto de hidrogênio, respectivamente; para a taxa de 28 L∙h-1∙m-2 as reduções foram de 89%, 92% e 100%. Os três processos mostraram ser efetivos para remover sulfeto de hidrogênio. A dessorção foi particularmente ineficiente na redução de Mn(II), ao contrário da oxidação com permanganato, onde a remoção atingiu cerca de 75% ao pH 8,0. A nanofiltração, nos ensaios realizados, atingiu os maiores valores de redução dos compostos estudados.Many regions in Brazil have problems associated with the water quality of their supplies, which bring problems to the production of safe drinking water that is distributed in communities. Generally, consumers judge the drinking water safety through the use of their organoleptic senses. The conventional processes used in water treatment are not effective to remove many compounds that cause color, taste and odor in water. For this reason water utilities frequently receive complaints by angry consumers unsatisfied with the quality of drinking water. Among the compounds that cause taste, odor and color in drinking water are hydrogen sulfide, iron and manganese. Sulfide generates a "rotten egg" smell, perceptible at concentrations between 0.05 and 0.1 mg·L-1. Manganese and iron are mainly associated with the formation of color and precipitates in water. The objective of this research was to study alternative treatment technologies to remove hydrogen sulfide, iron and manganese from drinking water. The investigated processes were air-stripping, nanofiltration and oxidation with potassium permanganate. Air stripping and nanofiltration pilot plants were supplied with water from Lomba do Sabão reservoir, located in Porto Alegre. Potassium permanganate oxidation was studied in laboratory using Jar tests systems and water from Lomba do Sabão. Oxidation tests associated with chemical clarification were performed in four different phases. In the first, the coagulants ferric chloride and aluminum sulfate were tested, with preparation of coagulation diagrams. In the second phase, it was measured the removal of Fe(II), Mn(II) and H2S during chemical clarification. The water oxidation demand was tested in the third experimental phase. Finally, the fourth phase encompassed tests using potassium permanganate associated with chemical clarification for the removal of Fe(II), Mn(II) and H2S. The results demonstrated that coagulation removed iron efficiently, but not manganese. Using permanganate, reductions in iron, manganese and sulfide increased to 92%, 59% and 94% (pH 7,0), and 93%, 74% and 100% (pH 8,0), respectively. Higher removals were achieved at pH 8,0 and one time the compounds stoichiometric oxidation relation. The air-stripping tower prototype was located at the Lomba do Sabão Water Treatment Plant. It operated with air to water ratios between of 8 and 12 m3:m3. Iron removal rates varied from 14% to 31%, while there were no removal for manganese. Hydrogen sulfide concentrations in plant’s effluents were below the detection level, showing full volatilization of the gas during stripping. The nanofiltration system prototype was also installed at Lomba do Sabão Water Treatment Plant. Tests were performed using flowrates of 2 and 4 L·min-1, corresponding to hydraulic application rates of 14 e 28 L∙h-1∙m-2 a 25°C. The rejections for the 14 L∙h-1∙m-2 tests were 91%, 96% and 100% (<LD) for iron, manganese and sulfide, respectively; for 28 L∙h-1∙m-2, the reductions achieved 89%, 92%, and 100%. The tested treatment processes were effective for hydrogen sulfide removal. Air-stripping was particularly inefficient for Mn(II) removal; on the contrary, permanganate oxidation reached 75% at pH 8,0. Tests with nanofiltration reached the highest removal rates for the studied compounds

Remoção de sulfeto de hidrogênio, ferro e manganês de águas de abastecimento através dos processos de dessorção gasosa, nanofiltração e oxidação com permanganato de potássio

Inúmeras regiões brasileiras apresentam problemas qualitativos em seus mananciais de abastecimento, originando dificuldades para a potabilização da água distribuída nas cidades. Geralmente, os consumidores julgam a segurança da água potável que bebem através de seus sentidos organolépticos. Os processos convencionais utilizados nas estações de tratamento de água não são efetivos na remoção de muitos compostos que causam cor, gosto e odor na água. Devido a isto, é comum que as companhias de saneamento recebam reclamações por parte dos consumidores sobre a qualidade da água distribuída. Dentre os compostos que causam gosto, odor e cor na água encontram-se o sulfeto de hidrogênio, o ferro e o manganês. O sulfeto gera um odor de “ovo podre”, perceptível a concentrações que variam entre 0,05 e 0,1 mg·L-1. Manganês e ferro estão associados principalmente a produção de cor e precipitados na água. Desta forma, o objetivo da pesquisa proposta foi estudar técnicas de tratamento alternativas as convencionais para controlar gosto, cor e odor na água potável pela presença de sulfeto de hidrogênio, ferro e manganês. Os processos investigados foram aeração em torre de dessorção, nanofiltração em membrana e oxidação com permanganato de potássio. Os testes foram realizados com água bruta oriunda do reservatório da Lomba do Sabão, em Porto Alegre. Os ensaios de oxidação anteriormente à clarificação físico-química constaram de 4 etapas. Na primeira, foram testados o cloreto férrico e o sulfato de alumínio, possibilitando a elaboração de diagramas de coagulação. Na segunda etapa, foi calculada a eficiência da coagulação na remoção de Fe(II), Mn(II) e H2S. Na terceira etapa, foi calculada a demanda do oxidante na água. Finalmente, na quarta etapa realizaram-se ensaios de oxidação do permanganato associado à clarificação físico-química. Os resultados mostraram que o processo de coagulação conseguiu remover o ferro satisfatoriamente, mas não o manganês. Nos ensaios usando permanganato os resultados mostraram que as remoções de ferro, manganês e sulfeto de hidrogênio foram de 92%; 59% e 94% (pH 7), e 93%; 74% e 100% (pH 8,0), respectivamente. No caso da relação estequiométrica, as reduções foram maiores quando foi usada a relação estequiométrica de 1,0 e pH 8,0 (89% para Mn e 95% para Fe). O protótipo de torre de dessorção, localizado na ETA Lomba do Sabão, foi operado com razões ar:água de 8 e 12 m3:m3. As remoções de ferro variaram entre 14% a 31%; para manganês, não houve redução aparente. As concentrações efluentes de sulfeto de hidrogênio foram inferiores ao limite de detecção do método analítico, mostrando que houve volatilização do gás neste processo. O protótipo do sistema de membranas de nanofiltração foi também instalado na ETA Lomba do Sabão. Foram realizados ensaios com vazões de 2 e 4 L∙min-1, correspondentes a taxas de aplicação de 14 e 28 L∙h-1∙m-2 a 25°C. As rejeições da membrana para a taxa de 14 L∙h-1∙m-2 foram de 91%, 96% e 100% (<LD) para ferro, manganês e sulfeto de hidrogênio, respectivamente; para a taxa de 28 L∙h-1∙m-2 as reduções foram de 89%, 92% e 100%. Os três processos mostraram ser efetivos para remover sulfeto de hidrogênio. A dessorção foi particularmente ineficiente na redução de Mn(II), ao contrário da oxidação com permanganato, onde a remoção atingiu cerca de 75% ao pH 8,0. A nanofiltração, nos ensaios realizados, atingiu os maiores valores de redução dos compostos estudados.Many regions in Brazil have problems associated with the water quality of their supplies, which bring problems to the production of safe drinking water that is distributed in communities. Generally, consumers judge the drinking water safety through the use of their organoleptic senses. The conventional processes used in water treatment are not effective to remove many compounds that cause color, taste and odor in water. For this reason water utilities frequently receive complaints by angry consumers unsatisfied with the quality of drinking water. Among the compounds that cause taste, odor and color in drinking water are hydrogen sulfide, iron and manganese. Sulfide generates a "rotten egg" smell, perceptible at concentrations between 0.05 and 0.1 mg·L-1. Manganese and iron are mainly associated with the formation of color and precipitates in water. The objective of this research was to study alternative treatment technologies to remove hydrogen sulfide, iron and manganese from drinking water. The investigated processes were air-stripping, nanofiltration and oxidation with potassium permanganate. Air stripping and nanofiltration pilot plants were supplied with water from Lomba do Sabão reservoir, located in Porto Alegre. Potassium permanganate oxidation was studied in laboratory using Jar tests systems and water from Lomba do Sabão. Oxidation tests associated with chemical clarification were performed in four different phases. In the first, the coagulants ferric chloride and aluminum sulfate were tested, with preparation of coagulation diagrams. In the second phase, it was measured the removal of Fe(II), Mn(II) and H2S during chemical clarification. The water oxidation demand was tested in the third experimental phase. Finally, the fourth phase encompassed tests using potassium permanganate associated with chemical clarification for the removal of Fe(II), Mn(II) and H2S. The results demonstrated that coagulation removed iron efficiently, but not manganese. Using permanganate, reductions in iron, manganese and sulfide increased to 92%, 59% and 94% (pH 7,0), and 93%, 74% and 100% (pH 8,0), respectively. Higher removals were achieved at pH 8,0 and one time the compounds stoichiometric oxidation relation. The air-stripping tower prototype was located at the Lomba do Sabão Water Treatment Plant. It operated with air to water ratios between of 8 and 12 m3:m3. Iron removal rates varied from 14% to 31%, while there were no removal for manganese. Hydrogen sulfide concentrations in plant’s effluents were below the detection level, showing full volatilization of the gas during stripping. The nanofiltration system prototype was also installed at Lomba do Sabão Water Treatment Plant. Tests were performed using flowrates of 2 and 4 L·min-1, corresponding to hydraulic application rates of 14 e 28 L∙h-1∙m-2 a 25°C. The rejections for the 14 L∙h-1∙m-2 tests were 91%, 96% and 100% (<LD) for iron, manganese and sulfide, respectively; for 28 L∙h-1∙m-2, the reductions achieved 89%, 92%, and 100%. The tested treatment processes were effective for hydrogen sulfide removal. Air-stripping was particularly inefficient for Mn(II) removal; on the contrary, permanganate oxidation reached 75% at pH 8,0. Tests with nanofiltration reached the highest removal rates for the studied compounds