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1.
Environ Pollut ; 334: 122174, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37451586

RESUMEN

The main purpose of this study was to build multivariate classification models using water quality monitoring data for the hydrographic basin of the Gualaxo do Norte River, Minas Gerais state, Brazil, which was impacted in 2015 by the rupture of a containment structure for iron ore tailings. A total of 27 points were evaluated, covering areas affected and unaffected by the disaster, with monitoring of chemical, physical, and microbiological variables during the period from July 2016 to June 2017. Multivariate classification techniques were applied to the data, with the aim of developing models to determine when the impacted locations would present characteristics equivalent to those existing prior to the rupture. Classification models constructed using PLS-DA and LDA were able to predict three classes: unaffected main river, affected main river, and tributaries. The first technique was able to clearly differentiate the three classes for the data evaluated, achieving averages corresponding to 90% accuracy. The second method was consistent with the first, identifying the chloride content, conductivity, turbidity, and alkalinity as discriminatory variables, among those monitored, with the relationships among the parameters being coherent with the environmental conditions of the region. The model, with a correct classification rate of 91.67%, enabled identification of the behavior of new samples, using only these easily measured variables. In summary, application of the multivariate statistical tools allowed the development of models capable of providing information about the recovery process of an ecosystem impacted by the greatest environmental disaster to have occurred in Brazil.


Asunto(s)
Contaminantes Químicos del Agua , Calidad del Agua , Monitoreo del Ambiente , Ecosistema , Ríos/química , Contaminantes Químicos del Agua/análisis , Brasil
2.
Environ Monit Assess ; 195(2): 337, 2023 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-36705892

RESUMEN

At the end of 2015, the Fundão dam belonging to the Samarco S.A. mining company was ruptured, releasing a flood of mud into the Gualaxo do Norte River, which advanced into the Doce River. The aim of the present study was to apply exploratory multivariate approaches to water quality data obtained during sampling campaigns at the Gualaxo do Norte River during the dry and rainy seasons, between July 2016 and June 2017. A total of 27 locations along the river were sampled, covering unaffected areas and regions influenced by the tailings waste from the dam. Determinations of chemical, physical, and microbiological water quality parameters were performed. Application of principal component analysis (PCA) resulted in the first two components together explaining 39.49% and 37.91% of the total variance for the dry and rainy season data, respectively. In both cases, the PCA groups were related to variables such as turbidity and total solids, which both presented higher values in regions affected by the mud flow. These results are in agreement with those obtained by the Kohonen neural network method, where two-dimensional maps confirmed the samples according to the affected and unaffected area by the disaster.


Asunto(s)
Contaminantes Químicos del Agua , Calidad del Agua , Ríos , Monitoreo del Ambiente , Brasil , Contaminantes Químicos del Agua/análisis
3.
Environ Sci Pollut Res Int ; 28(47): 67822-67832, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34268682

RESUMEN

Antibiotics have become a concern in the aquatic environments owing to the potential development of bacterial resistances. Thus, this study evaluated the removal of cephalexin (CEP) and erythromycin (ERY) from a local wastewater treatment plant (WWTP) effluent, mediated by microalgae-bacteria consortium. Likewise, the removal of correlated antibiotics resistance genes blaTEM and ermB was also assessed. The incubation results showed that the added concentrations of selected antibiotics did not restrain the consortium growth. Moreover, CEP and ERY were almost completely removed after the cultivation period, reaching total removals of 96.54% and 92.38%, respectively. The symbiotic interaction between microalgae and bacteria plays a role in the kinetics removal of CEP and ERY. The abundance of blaTEM and ermB was reduced by 0.56 and 1.75 logs, respectively. Lastly, our results suggest that technology based on natural microalgae-bacteria consortium could be a potential alternative to improve the quality of WWTP effluents.


Asunto(s)
Microalgas , Purificación del Agua , Antibacterianos , Bacterias/genética , Cefalexina , Eritromicina , Aguas Residuales/análisis
4.
Environ Sci Pollut Res Int ; 28(36): 50593-50601, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33963994

RESUMEN

The hydraulic characteristics of the Gualaxo do Norte River (RGN), a tributary of the upper Rio Doce basin, were affected in November 2015 by the rupture of the iron ore tailings dam at Fundão, in Bento Rodrigues, Mariana, Minas Gerais. We analyzed two sections of the RGN, located upstream and downstream of the Fundão dam. Measurements were taken at 11 stations along the main river in distinct seasonal periods, including river depth, river width, velocity, and flow. We also calculated the deoxygenation coefficient (K1) and the reaeration coefficient (K2) and collected elaborate bathymetric profiles of the sections. Anthropogenic interference influenced the river's hydraulic characteristics mainly in relation to the depth. In upstream sections, the changes are believed to be due to mining activities at the head of the river, while downstream effects were due to the introduction of iron ore tailings coming from the rupture of the Fundão dam. Despite these influences, deoxygenation coefficient values were typical for clean water, and the reaeration coefficient findings show that the RGN is efficient at biological degradation of the organic matter even receiving untreated domestic sewage from riparian communities. With the results obtained in this work, we seek to replicate a source of information about the current state of the region and to contribute information to future river planning, control, and restoration projects.


Asunto(s)
Monitoreo del Ambiente , Contaminantes Químicos del Agua , Brasil , Minería , Ríos , Agua , Contaminantes Químicos del Agua/análisis
5.
Environ Sci Pollut Res Int ; 28(18): 23235-23242, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33442807

RESUMEN

The Brazilian Biodigester Septic Tank (BBST) is an on-site appropriate technology for blackwater treatment, which was developed to yield an effluent suitable for agricultural use. Although several studies have proven its efficacy for secondary blackwater treatment, there are few published studies about the microbiological quality of its effluent, and most of them focus on the quantification of total or thermotolerant coliforms. This study evaluates the performance of a BBST for the removal of human adenovirus (HAdV), Enterococcus spp., Salmonella sp., and Escherichia coli. The results further clarify the safety and risks associated with the reuse of the obtained effluent. The full-scale system consists of three 1.2 m3 interconnected reactors, with a blackwater input of 0.045 m3/day, and hydraulic retention time of 80 days. Six sample campaigns were performed at different stages of the monthly operating cycle. The system presented an average removal efficiency of 5.09 log10 for E. coli, 3.22 log10 for Enterococcus spp., 1.2 log10 for Salmonella sp., and 3.0 log10 for HAdV. According to the World Health Organization standards, the obtained effluent is suitable for subsurface irrigation, and for use in crops that develop distant from the soil or highly mechanized crop systems.


Asunto(s)
Escherichia coli , Aguas Residuales , Brasil , Humanos , Salmonella , Suelo , Eliminación de Residuos Líquidos , Aguas Residuales/análisis
6.
Sci Total Environ ; 749: 141441, 2020 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-32836119

RESUMEN

Sulfamethoxazole (SMX) has been commonly detected in wastewater treatment plant (WWTP) effluents. SMX and other antibiotics can be considered as environmental contaminants of emerging concern. Due to their toxicity effects and their potential for the development of bacterial resistance their presence in aquatic compartment becomes a threat to human health. This study evaluated the bioremediation of SMX in WWTP effluents using a tertiary treatment composed by microalgae-bacteria consortium under low intensity artificial LED illumination, and also the assessment of sulfonamide resistance gene (sul1). The removal of SMX from WWTP effluents were 54.34 ± 2.35%, in which the microalgae-bacteria consortium improves the removal performance of SMX. The main process of SMX removal can be attributed to the symbiotic biodegradation by bacteria due to the increase of oxygen released by the microalgae photosynthetic process. Therefore, the microalgae-bacteria consortium used in this study, demonstrated to be a promising alternative for bioremediation of SMX, with potential for removal others contaminants from wastewater effluent. However, the residual SMX and the relative abundance of antibiotics resistance genes (ARG) found in this study suggest that SMX contributes to selective pressure for ARG maintenance and proliferation in WWTP effluent. Thus, further studies to removal ARG from WWTP effluent are needed.


Asunto(s)
Microalgas , Purificación del Agua , Antibacterianos/toxicidad , Bacterias , Biodegradación Ambiental , Farmacorresistencia Microbiana , Humanos , Sulfametoxazol/toxicidad , Aguas Residuales
7.
Environ Sci Pollut Res Int ; 27(17): 21013-21020, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32266618

RESUMEN

Faster spread of epidemics has turned local concerns into global crises; antimicrobial resistance (AMR) is being considered a major threat to public health in the twenty-first century. Antibiotic misuse plays a great role in accelerated AMR; thus, understanding and discussing consumption patterns has been a trend topic over the past years. Developing countries, such as Brazil, have high growth rates in antibiotic consumption, potentially impacting global environmental safety. This study presents the compiled information from the Brazilian Health Regulatory Agency (ANVISA) on antibiotic dispensation across the country and maps the consumption trends between the years of 2013 and 2016. The most consumed substances were beta-lactams (amoxicillin and cephalexin) and macrolides (azithromycin). National relative growth consumption in the mentioned period was 18%. At the local level, growth of consumption ranged from 4 to 85%, with rampage growth concentrated in the North and Northeast regions. Brazilian laws, such as restriction of over-the-counter sales and mandatory report on dispensation, seem to have little effect on the national antibiotic consumption growth. This phenomenon growth is still elevated if compared with developed countries, demonstrating the need for further surveillance as well as coordinated efforts aiming at antibiotic use and AMR prevention.


Asunto(s)
Antibacterianos/uso terapéutico , Países en Desarrollo , Amoxicilina , Brasil , Macrólidos
8.
Environ Sci Pollut Res Int ; 27(4): 4365-4375, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31832945

RESUMEN

The rupture of the Fundão dam released about 39 million m3 of tailings into the Rio Doce/Brazil. The sediment load increase in the affected rivers has become a concern. As such, this article provides recent information about the region. In addition, based on past studies in the region, it shows the magnitude and dynamics of the environmental impacts caused by the rupture of the dam on the bottom sediments. Sediment samples in different seasonal periods were collected at eleven sampling stations located along the Gualaxo do Norte River, the first tributary of the Rio Doce affected by the environmental disaster. These sediments underwent physical, chemical, and granulometric analyses for their organic, metal, and semimetal content. The contamination factor and the enrichment factor of the samples also were calculated. To evaluate the anthropogenic contributions to sediment metal concentrations, reference values (regional background values) for the Gualaxo do Norte River were used. The results indicate that, in the sampling stations not affected by the disaster, the concentrations of the metals and semimetals reflect the geology of the Quadrilátero Ferrífero. However, in the area affected by the environmental disaster, there were changes in the chemical and physical properties of the bottom sediment, mainly in the concentrations of iron, organic matter, and fine sediment fractions. This was reflected in the contamination factors and enrichment factors calculated for the sediments of the sampling stations. Iron and manganese concentrations in sediments are much higher than other rivers in the world that are unaffected by mining activities. The observed changes in the bottom sediments of the river suggest a need for constant monitoring of the iron because the iron oxide minerals present in silt and clay have a high adsorption capacity. In the long term, these factors may contribute to the decrease of the quality of these sediments and consequently of the waters and biota present in these environments.


Asunto(s)
Monitoreo del Ambiente , Sedimentos Geológicos/química , Minería , Ríos , Contaminantes Químicos del Agua/química , Brasil
9.
Arch Environ Contam Toxicol ; 77(1): 144-153, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30976887

RESUMEN

The 2015 rupture of the Fundão dam near the district of Bento Rodrigues in Mariana, Minas Gerais, Brazil, released around 50 million m3 of iron ore tailings. The first tributary of the Rio Doceto receive this waste was the Gualaxo do Norte River. Many groups in Brazil and from around the world have studied the environmental and social impacts of this disaster. However, relationships between the introduction of mining waste, the geological complexity of the area, and the presence of pathogenic organisms have not yet been investigated. The present study aimed to measure the concentrations of enteric pathogens along the Gualaxo do Norte River after the environmental disaster and to correlate their abundance with the presence of metals and semimetals coming from both mining tailings and geological sources. For this purpose, we collected water samples from 27 stations along the entire basin during a hydrological year. The concentrations of metals and semimetals measured in this study were generally within limits established by national and international legislation, except for those of iron and manganese. Positive correlations between the human adenovirus (HAdV) and arsenic, barium, iron, lead, manganese, and nickel were confirmed, allowing us to observe that there is an abundance of the potentially infectious virus present in the studied sites containing metal/semimetal concentrations. These studies indicate the importance of investigations that consider viral enteric pathogens complexed with metals and may favor the stability and prolongation of the infectivity of such pathogens in water destined for human and animal usage.


Asunto(s)
Adenovirus Humanos/aislamiento & purificación , Metales/análisis , Ríos/química , Ríos/virología , Contaminantes Químicos del Agua/análisis , Brasil , Monitoreo del Ambiente , Humanos , Minería
10.
Food Environ Virol ; 11(2): 178-183, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30747345

RESUMEN

Although the effects of heavy metals on the behavior, including infectivity, of bacteria have been studied, little information is available about their effects on enteric viruses. We report an investigation of effects on the biosynthesis of human adenoviruses (HAdV) and hepatitis A (HAV) of waters contaminated with mineral waste following an environmental disaster in Mariana City, Minas Gerais State, Brazil. The study area was affected on November 5, 2015, by 60 million m3 of mud (containing very high concentrations of iron salts) from a mining reservoir (Fundão), reaching the Gualaxo do Norte River (sites evaluated in this study), the "Rio Doce" River and finally the Atlantic Ocean. We found substantial counts of infectious HAdV and HAV (by qPCR) in all sampled sites from Gualaxo do Norte River, indicating poor basic sanitation in this area. The effects of iron on viral infection processes were evaluated using HAdV-2 and HAV-175, as DNA and RNA enteric virus models, respectively, propagated in the laboratory and exposed to this contaminated water. Experiments in field and laboratory scales found that the numbers of plaque forming units (PFU) of HAdV and HAV were significantly higher in contaminated water with high iron concentrations than in waters with low iron concentration (< 20 µg/L of iron). These findings indicate that iron can potentiate enteric virus infectivity, posing a potential risk to human and animal health, particularly during pollution disasters such as that described here in Mariana, Brazil.


Asunto(s)
Adenovirus Humanos/crecimiento & desarrollo , Virus de la Hepatitis A/crecimiento & desarrollo , Hierro/análisis , Minerales/análisis , Ríos/virología , Infecciones por Adenovirus Humanos/virología , Adenovirus Humanos/genética , Adenovirus Humanos/aislamiento & purificación , Adenovirus Humanos/metabolismo , Brasil , Enterovirus/genética , Enterovirus/crecimiento & desarrollo , Enterovirus/aislamiento & purificación , Enterovirus/metabolismo , Monitoreo del Ambiente , Hepatitis A/virología , Virus de la Hepatitis A/genética , Virus de la Hepatitis A/aislamiento & purificación , Virus de la Hepatitis A/metabolismo , Humanos , Hierro/metabolismo , Minería , Ríos/química , Contaminación del Agua
11.
Eng. sanit. ambient ; 23(4): 767-778, jul.-ago. 2018. tab, graf
Artículo en Portugués | LILACS | ID: biblio-953285

RESUMEN

RESUMO O presente estudo foi realizado na bacia hidrográfica do Rio do Peixe, Quadrilátero Ferrífero (QF), em Minas Gerais. Essa bacia apresenta um cenário geológico distinto e atividades antrópicas diversificadas, como a mineração de ferro, ouro e gemas, a agropecuária e a silvicultura. O principal objetivo desta pesquisa foi investigar as possíveis fontes de contribuições antropogênicas dos metais em sedimentos de fundo. Para isso, foram realizadas duas campanhas com amostragens de sedimentos de fundo em 12 pontos da bacia, nos meses de março e julho de 2015. A partir da técnica analítica de espectrometria de emissão óptica com plasma, foram detectadas concentrações de Al, Ca, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti e Zn nos sedimentos de fundo. Os resultados dos indicadores da qualidade dos sedimentos fator de contaminação (FC), fator de enriquecimento (FE) e índice de geoacumulação (IGEO) demonstraram que há interferências antrópicas, sendo as atividades minerárias e industriais, o despejo de efluentes domésticos e o uso e a ocupação do solo inapropriado apontados como as principais fontes de contaminação de metais da bacia.


ABSTRACT The present study was carried out in the river basin area of Rio do Peixe, Iron Quadrangle, in Minas Gerais, Brazil. This basin presents geological scenario and diversified anthropic activities, such as iron, gold and gems mining, agriculture, and forestry. The main objective of this research was to investigate the possible sources of anthropogenic contributions of metals in bottom sediments. Thus, two surveys were carried out on bottom sediments at twelve basin sites from March to July of 2015. Based on the plasma optical emission spectrometry analytical technique, we found concentrations of Al, Ca, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti and Zn in the bottom sediments. The results of the FC, FE and IGEO sediment quality indicators showed that there are anthropic interferences, in which mining and industrial activities, disposal of domestic effluents and use and occupation of inappropriate soil are identified as the main sources of metals contamination of the basin.

12.
Eng. sanit. ambient ; 23(3): 543-556, maio-jun. 2018. tab, graf
Artículo en Portugués | LILACS | ID: biblio-953254

RESUMEN

RESUMO O Indicador de Salubridade Ambiental (ISA) foi criado, em 1999, pelo Conselho Estadual de Saneamento (Conesan) do Estado de São Paulo. Embora tenha sido formado com o objetivo de medir o nível de salubridade ambiental dos municípios paulistas, o ISA tem sido utilizado em diversas Regiões do Brasil. Além disso, ao longo desses 17 anos, o ISA vem sendo alterado em sua formulação original, de acordo com as características do local a ser avaliado, como é sugerido pelo manual que o originou. Diante disso, o objetivo deste artigo foi avaliar o estado da arte da utilização do ISA no Brasil, identificando avanços, lacunas e desafios de seu uso. Para isso, realizou-se amplo levantamento bibliográfico a fim de encontrar estudos disponíveis em meios eletrônicos que utilizaram o ISA. Foram identificados e analisados 60 casos. As Regiões Nordeste e Sul do país são as que possuem a maior quantidade de estudos e a maioria deles (41,6%) é resultado de dissertações de mestrado. Cada estudo utiliza, em média, seis indicadores de primeira ordem e a revisão bibliográfica é método preponderante para escolhê-los e ponderá-los. Por fim, foi mostrado que as diferenças entre os ISA na verdade são um empecilho para a utilização desse indicador. Uma vez que cada estudo possui suas peculiaridades em termos de indicadores, pesos e critérios de cálculo, só é possível fazer comparações dos resultados obtidos entre um mesmo estudo ao longo do tempo, mas essas diferenças impossibilitam a comparação entre os valores obtidos em diferentes estudos.


ABSTRACT The Environmental Health Indicator (Indicador de Salubridade Ambiental - ISA) was established in 1999 by the São Paulo's State Council of Sanitation (Conesan). Although this indicator was created to measure the level of environmental health of the municipalities in São Paulo state, Brazil, ISA has been applied in several other regions of Brazil. Moreover, throughout these 17 years, the original ISA formulation has been altered according with local characteristics, as suggested by the manual that originated it. Thus, this study aimed to evaluate ISA application state of the art in Brazil, by the identification of the progress, gaps, and challenges of its use. An extensive literature investigation was performed in order to find studies available in electronic media that used ISA. We identified and analyzed 60 cases. The Northeast and South regions are those with the greatest number of studies, and the majority of them (41.6%) are result of master's dissertations. Each study uses an average of six first order indicators, and the literature review is the predominant method for choosing and evaluating them. Finally, we showed that the differences between the ISAs are actually a drawback for this indicator use. Since each study has peculiarities in terms of indicators, weights, and criteria calculation, it is only possible to compare the results from the same study over time, but these differences preclude the comparison between the values obtained in different studies.

13.
Eng. sanit. ambient ; 23(3): 579-590, maio-jun. 2018. tab, graf
Artículo en Portugués | LILACS | ID: biblio-953259

RESUMEN

RESUMO Esta pesquisa científica teve como principal objetivo identificar patótipos de Escherichia coli diarreiogênica nas águas superficiais da Bacia Hidrográfica do Rio Xopotó, na região do Alto Rio Doce, Minas Gerais. Os estudos referentes às estirpes diarreiogênicas de E. coli no meio ambiente no Brasil são escassos. A bacia hidrográfica escolhida para o estudo sofre intensa degradação ambiental devido ao lançamento de esgoto in natura em seus corpos d'água e às atividades antrópicas, como a agropecuária. As coletas de água nos 13 pontos amostrais foram realizadas em duas épocas do ano de 2015 (abril e julho). Para identificação dos genes de E. coli diarreiogênica, utilizou-se o método de reação em cadeia da polimerase (PCR). A bacia hidrográfica apresentou contaminação diarreiogênica de patótipos E. coli produtora de toxina Shiga (STEC), E. coli enteropatogênica (EPEC) e E. coli enterotoxigênica (ETEC), tal ocorrência foi constante em ambas as campanhas. Os genes de virulência observados foram: na STEC, toxina Shiga (Stx1), responsável por causar doenças renais graves, como a síndrome hemolítico-urêmica (SHU); já a EPEC apresentou somente o gene virulento eae, característico do subgrupo atípico (aEPEC); a ETEC apresentou toxinas termolábeis (LT). A presença desses patótipos representa potencial risco de doenças diarreiogênicas na população que utiliza os recursos hídricos, particularmente idosos e crianças, e evidencia o comprometimento da qualidade microbiológica dos cursos d'água constituintes da Bacia Hidrográfica do Rio Xopotó, decorrente principalmente da ausência de estações de tratamento de esgoto (ETEs).


ABSTRACT The main purpose of this scientific research was to identify pathotypes of diarrheogenic Escherichia coli in the watershed of Xopotó River, in Alto do Rio Doce, Minas Gerais region, Brazil. The studies referring to the stirps diarrheagenics of E. coli in the environment in Brazil are scarce. The watershed chosen for the study suffers intense environmental degradation due the release of raw sewage into their water bodies and human activities, such as agriculture. The water collecting at 13 sampling points were held in two periods of the year 2015 (April and July). For the identification of the genes of diarrheagenic E. coli, the method of reaction polymerase chain (PCR) was used. The watershed presented pathogenic contamination of pathotypes Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC) such a constant occurrence in both campaigns. The virulence genes observed were: STEC, Shiga toxin (Stx1), responsible for causing severe kidney disease as hemolytic-uremic syndrome (HUS). Besides that, EPEC presented only the virulent gene eae, characteristic of the atypical subgroup (aEPEC), as well as thermolabile toxins (LT). The presence of these pathotypes represents potential risk of diarrheagenic diseases in the population that uses the water resources, particularly the elderly and children, and demonstrates the commitment of the microbiological quality of constituents watercourses of the watershed of Xopotó River, mainly because the lack of sewage treatment facilities.

14.
Environ Sci Pollut Res Int ; 24(8): 7456-7467, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28110455

RESUMEN

In developing countries, it is uncommon to find watersheds that have been the object of detailed environmental studies. It makes the assessment of the magnitude of environmental impacts and pollution of these sites difficult. This research demonstrated ways to understand the dynamics of river bottom sediments contamination, even for watersheds with a lack of environmental data. Based on geochemical affinity, we conducted a comprehensive study on the concentration of metals and metalloids. Then, we discussed the probable origin of the concentration of these elements at the bottom sediment along the Matipó River. The Matipó River is an important tributary of the Doce River, which stood out in international headlines because of the mining tailing dam disaster in Mariana, Minas Gerais, in 2015. The bottom sediment samples were taken in 25 stations located along the basin in different seasonal periods. The results showed that copper ([Formula: see text] = 464.7 mg kg-1) and zinc ([Formula: see text] = 287.7 mg kg-1) probably have natural origin, despite of the high concentrations. Lead ([Formula: see text] = 28.0 mg kg-1), chromium ([Formula: see text] = 153.2 mg kg-1), and nickel ([Formula: see text] = 41.8 mg kg-1) also had high concentrations at some collecting stations, and this probably reflected the local natural conditions. The bedrock of the studying basin is dominantly composed of metabasalts and metatonalites interlayered with calcitic and dolomitic metalimestone. On the other hand, the concentration was worrisome in stations near human activities, possibly due to impacts caused by unsustainably agriculture and livestock.


Asunto(s)
Monitoreo del Ambiente , Sedimentos Geológicos/química , Metaloides/análisis , Metales Pesados/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , Agricultura , Brasil
15.
Water Sci Technol ; 71(8): 1229-34, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25909734

RESUMEN

The production of different species of microalgae in consortium with other micro-organisms from wastewaters may represent an alternative process, to reduce the costs, for obtaining biofuels. The aim of this study was to evaluate the influence of pre-ultraviolet disinfection (UV) in the production of lipids from biomass produced in high rate ponds. Two high rate algal ponds were evaluated: a pond that received domestic sewage without disinfection and the other receiving domestic sewage previously disinfected by UV radiation (uvHRAP). The UV disinfection did not lead to significant differences in fatty acid profile and total lipid productivities, although it increased algal biomass concentration and productivity as well as lipid content. Moreover, the overall biomass concentrations and productivities decreased with the UV disinfection, mostly as a consequence of a loss in bacterial load. We thus conclude that uvHRAP disinfection may represent a potential strategy to promote the cleaner and safer growth of algal biomass when cultivated in consortium with other micro-organisms. Mainly regarding the use of wastewater as culture medium, together with a cheaper production of lipids for biodiesel, pre-disinfection may represent an advance since extraction costs could be significantly trimmed due to the increase in lipid content.


Asunto(s)
Biocombustibles , Lípidos/química , Microalgas/metabolismo , Estanques , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Biomasa , Desinfectantes , Desinfección , Metabolismo de los Lípidos , Aguas del Alcantarillado
16.
Environ Technol ; 35(17-20): 2296-305, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25145183

RESUMEN

The objective of this paper is to compare the lipid content and composition ofbiomass produced by a consortium of microalgae and bacteria, cultivated under different solar radiation intensities and tropical conditions in pilot-scale high-rate ponds (HRPs) using domestic sewage as culture medium. The treatment system consisted of an upflow anaerobic sludge blanket reactor followed by UV disinfection and six HRPs covered with shading screens that blocked 9%, 18%, 30%, 60% and 80% of the solar radiation. The total lipid content does not vary significantly among the units, showing a medium value of 9.5%. The results show that blocking over 30% of the solar radiation has a negative effect on the lipid productivity. The units with no shading and with 30% and 60% of solar radiation blocking have statistically significant lipid productivities, varying from 0.92 to 0.96 gm(-2) day(-1). Besides radiation, other variables such as volatile suspended solids and chlorophyll-a are able to explain the lipid accumulation. The lipid profile has a predominance of C16, C18:1 and C18:3 acids. The unsaturation of fatty acids increases with the reduction in solar radiation. On the other hand, the effect of polyunsaturation is not observed, which is probably due to the presence of a complex and diverse biomass.


Asunto(s)
Biomasa , Reactores Biológicos , Metabolismo de los Lípidos/efectos de la radiación , Microalgas , Aguas del Alcantarillado , Energía Solar , Bacterias/química , Bacterias/metabolismo , Biocombustibles , Concentración de Iones de Hidrógeno , Lípidos/análisis , Lípidos/química , Microalgas/química , Microalgas/metabolismo , Oxígeno , Fitoplancton , Temperatura
17.
Environ Technol ; 34(13-16): 1877-85, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24350441

RESUMEN

Algal biomass production associated with wastewater is usually carried out in high rate algal ponds (HRAPs), which are concomitantly used in the treatment of such effluent. However, most types of wastewater have high levels of bacteria that can inhibit the growth of algal biomass by competing for space and nutrients. The objective of this study was to assess the influence of ultraviolet (UV) pre-disinfection on the performance of HRAPs used for wastewater treatment and algal biomass production. Two HRAPs were tested: one received effluent from an upflow anaerobic sludge blanket (UASB) reactor- HRAP -and the second received UASB effluent pre-disinfected by UV radiation-(UV)HRAP. Physical, chemical and microbiological parameters were monitored, as well as algal biomass productivity and daily pH and dissolved oxygen (DO) variation. The (UV)HRAP presented highest DO and pH values, as well as greater percentage of chlorophyll a in the biomass, which indicates greater algal biomass productivity. The average percentages of chlorophyll a found in the biomass obtained from the HRAP and the (UV)HRAP were 0.95 +/- 0.65% and 1.58 +/- 0.65%, respectively. However, total biomass productivity was greater in the HRAP (11.4 gVSSm(-2) day(-1)) compared with the (UV)HRAP (9.3 gVSSm(-2) day(-1)). Mean pH values were 7.7 +/- 0.7 in the HRAP and 8.1 +/- 1.0 in the (UV)HRAP, and mean values of DO percent saturation were 87 +/- 26% and 112 +/- 31% for the HRAP and the (UV)HRAP, respectively. Despite these differences, removal efficiencies of organic carbon, chemical oxygen demand, ammoniacal nitrogen and soluble phosphorus were statistically equal at the 5% significance level.


Asunto(s)
Biomasa , Fitoplancton/crecimiento & desarrollo , Fitoplancton/metabolismo , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Aguas Residuales/microbiología , Reactores Biológicos/microbiología , Chlorella/crecimiento & desarrollo , Chlorella/metabolismo , Clorofila/metabolismo , Desinfección/métodos , Concentración de Iones de Hidrógeno , Oxígeno , Rayos Ultravioleta
19.
Eng. sanit. ambient ; 14(1): 19-28, jan.-mar. 2009. mapas, tab
Artículo en Portugués | LILACS | ID: lil-512043

RESUMEN

A qualidade de vida de uma população está diretamente relacionada com a infraestrutura urbana em que a mesma está inserida. Nesse sentido, o objetivo do estudo foi avaliar a saúde pública da área urbana do município de Tucuruí no Pará, sob o ponto de vista das condições do saneamento ambiental e a composição de um sistema com menor quantidade de variáveis para discriminar áreas com distintos níveis sanitário-ambientais, e relacionar esses indicadores com a ocorrência de agravos à saúde nessas áreas. O município de Tucuruí foi selecionado para a área de estudo devido à deficiência de sua infraestrutura sanitária, alta taxa de crescimento da população, e a forte incidência de doenças tropicais relacionadas diretamente com as condições sanitárias.


The quality of life from a population is directly related to urban infrastructure on which it is embedded. Accordingly, the objective of the study was to evaluate the public health in the municipality of Tucuruí in Pará, under conditions of environmental sanitation to the composition of a system with a smaller number of variables to discriminate areas with different levels of sanitary and environmental health, and relate these indicators with the occurrence of diseases related to health in these areas. The municipality of Tucuruí was selected for the study area due to the deficiency of their health infrastructure, high rate of population growth, and high incidence of tropical diseases directly related to the health conditions.

20.
Eng. sanit. ambient ; 12(3): 335-342, jul.-set. 2007. ilus, mapas, tab
Artículo en Portugués | LILACS | ID: lil-466569

RESUMEN

Este trabalho teve por objetivo a proposição de cenários para o equacionamento da disposição de resíduos sólidos gerados por áreas urbanas da região do Baixo Ribeira de Iguape, localizado no estado de São Paulo. Utilizou-se a análise multicritério, que requer a identificação de critérios que podem ser restrições e fatores. Como critérios de agregação optou-se pela Combinação Linear Ponderada e pela Média Ponderada Ordenada. Para cada um dos municípios calculou-se a área necessária para a disposição final de seus resíduos sólidos. Os resultados mostraram que a melhor área para o município de Cajati está localizada a aproximadamente 3,0km da sede do mesmo, para Jacupiranga a 2,7km e para Pariqüera-Açu a 2,4km. A metodologia mostrou-se adequada ao propósito em questão, levando-se em consideração 18 fatores e restrições influentes no processo de decisão.


This paper addresses the proposition of scenarios for the equation of the disposal of solid residues generated by urban areas of the region of the Baixo Ribeira de Iguape, located in the São Paulo State, Brazil. Multicriterion analysis requiring identification of criteria that can play restrictions and factors roles were used. Aggregation Criteria was represented by the Weighed Linear Combination and the Ordered Weighed Mean. For each one of the selected cities it was calculated the required area for the final disposal of its solid residues. The results had shown that the best area for the city of Cajati is located approximately 3,0 km of its headquarters, for Jacupiranga 2,7 km and for Pariqüera-Açu 2,4 km. The applied methodology revealed adequate to the objective of this research, taking into account 18 influential factors and restrictions in the decision process.


Asunto(s)
Eliminación de Residuos , Rellenos Sanitarios , Selección del Sitio de Tratamiento de Residuos , Criterios de Calidad del Suelo , Residuos Sólidos
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