DECIV - Artigos publicados em periódicos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/497
Navegar
23 resultados
Resultados da Pesquisa
Item Inactivation of Escherichia coli in photobioreactors with microalgae and illuminated by light emitting diodes.(2022) Silva, Ludymyla Marcelle Lima; Santiago, Aníbal da Fonseca; Silva, Gilmare Antônia da; Lima, Lívia Bastos de; Amaral, L. P.; Nascimento, Rafael Souza LeopoldinoPathogens in wastewater must be inactivated to prevent the spread of waterborne diseases and allow reuse of the water after treatment. One of the options for wastewater treatment is to use photobioreactors with microalgae. Such systems can inactivate pathogens by diferent mechanisms, and Escherichia coli can be used as an indicator of inactivation. Therefore, this study aimed to evaluate inactivation of E. coli in wastewater by means of light emitting diodes (LED)-illuminated photobioreactors with microalgae, without the emission of ultraviolet radiation (UV). Two optimization steps were carried out, in which LED-illuminated photobioreactors without UV emission were set up for the treatment of wastewater, and various exposure times and luminous fuxes were tested for three wavelengths (white, blue and red); they were compared with photobioreactors illuminated by sunlight and in the dark. Additionally, using the results obtained in the optimization, a scaled-up reactor approximately 8.5 times larger in volume was operated to evaluate whether the behavior would be maintained at this scale. The removal efciency was 5.06 logarithmic units. Photobioreactors illuminated with a blue LED with luminous fux of 700 µmol m−2 s −1 and operated for 15 days showed the best performance in the inactivation of E. coli. LED-illuminated photobioreactors with microalgae, without the emission of ultraviolet radiation (UV) presents inactivation of pathogens and has the advantage of the low cost of the lamps, and the ease of operation.Item Removal of cephalexin and erythromycin antibiotics, and their resistance genes, by microalgae-bacteria consortium from wastewater treatment plant secondary effluents.(2021) Rodrigues, Daniel Aparecido da Silva; Cunha, Camila Cristina Rodrigues Ferreira da; Espirito Santo, Daiana Rocha do; Barros, André Luis Corrêa de; Pereira, Andressa Rezende; Silva, Silvana de Queiroz; Santiago, Aníbal da Fonseca; Afonso, Robson José de Cássia FrancoAntibiotics 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.Item Rural blackwater treatment by a full-scale Brazilian Biodigester Septic Tank : microbial indicators and pathogen removal efficiency.(2021) Oliveira, Thaíssa Jucá Jardim; Santiago, Aníbal da Fonseca; Lanna, Maria Célia da Silva; Fongaro, Gislaine; Milagres, Natália Ladeira; Cunha, Thalita Ramos; Corrêa, Andreíza Liká ItóThe 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 Enterococcusspp., 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.Item Optimization and scale-up of an LED-illuminated microalgal photobioreactor for wastewater treatment.(2020) Silva, Ludymyla Marcelle Lima; Santiago, Aníbal da Fonseca; Castro, Ana Leticia Pilz de; Bastos, Leonardo de Souza; Periard, Lucas; Vassoler, FábioThe use of light-emitting diode (LED)-illuminated photobioreactors with microalgae has been extensively studied for wastewater treatment. Most studies have used isolated microalgae species; however, this practice does not match the reality of conditions in wastewater treatment plants. Operational conditions that promote greater growth of algal biomass and that remove pollutants most effectively are disputed in the literature. In this context, LED-illuminated photobioreactors with microalgae were evaluated using multivariate analysis in order to optimize removal of pollutants (nitrogen, phosphorus, and carbonaceous organic matter). Three variables were evaluated: operating time, LED wavelength, and luminous flux intensity. A microalgae consortium was used in the photobioreactor. In addition to the LED-illuminated photobioreactors, control photobioreactors illuminated by sunlight were also operated. Using the results obtained in the optimization, a scaled-up reactor approximately 8.5 times larger in volume was operated to evaluate if the behavior would be maintained. The best operational conditions for the removal of pollutants were observed in LED-illuminated photobioreactors operated under a light intensity of 700 μmol·m 2 s 1 for 15 days. Under these conditions, it was possible to remove 89.97% of carbonaceous organic matter, 86.50% of nitrogen, and 30.64% of phosphorus. The scaled-up photobioreactor operated with similar performance.Item Tratamento de águas residuárias em fotobiorreatores de fluxo contínuo iluminados por luz artificial e solar.(2020) Nascimento, Rafael Souza Leopoldino; Silva, Ludymyla Marcelle Lima; Periard, Lucas; Santiago, Aníbal da FonsecaA tecnologia de fotobiorreatores de microalgas e iluminados por LEDs tem sido amplamente estudada para o tratamento de águas residuárias. Porém, a luz solar é um recurso gratuito e deve ser aproveitado. Mas permanece a dúvida se os fotobiorreatores iluminados por luz natural (solar) em combinação com luz artificial podem ter maior estabilidade operacional ou maior desempenho quando comparados com sistema iluminados só por luz artificial. Neste contexto, fotobiorreatores de fluxo contínuo iluminados por Diodos Emissores de Luz (LEDs) combinados, ou não, com luz solar foram operados e tiveram seu desempenho avaliado. A variáveis analisadas foram pH, OD, demanda química de oxigênio (DQO), clorofila a e sólidos suspensos totais. Os fotobiorreatores foram eficazes para a remoção de matéria orgânica, sendo 75 ± 15 % no fotobiorreator iluminado por LED e 65 ± 10% no fotobiorreator iluminado por luz solar e LED. Os resultados mostraram que o uso da iluminação combinada favorece a produção de oxigênio dissolvido, e garante maior estabilidade operacional na remoção de matéria orgânica carbonácea.Item Duas décadas do curso de Engenharia Ambiental na visão dos egressos da Escola de Minas da Universidade Federal de Ouro Preto.(2020) Santiago, Aníbal da Fonseca; Prado Filho, José Francisco do; Dias, Lívia Cristina Pinto; Gomes, Gustavo Silva Magalhães; Lima, Lívia Bastos de; Mol, Ítalo César Rosa; Martins, Maria Clara SantosA Engenharia Ambiental, uma modalidade relativamente nova de engenharia, ainda anseia por maiores debates sobre a formação e atuação profissional. As pesquisas com egressos podem subsidiar a discussão e proposições sobre o ensino da engenharia. Esse estudo apresenta uma pesquisa exploratória e quali-quantitativa com egressos da Engenharia Ambiental da EM/UFOP quanto às suas percepções sobre o curso, o mercado de trabalho e a relação entre os conteúdos recebidos na graduação e a realidade profissional. O questionário online aplicado (método survey) identificou a necessidade da ampliação da articulação entre os conteúdos teóricos e as situações reais de trabalho – o que corrobora para as atuais tendências de ensino em engenharia voltado para um currículo baseado em projetos e outras metodologias ativas. A articulação entre o conteúdo teórico e prático também esteve presente nos motivos para aumento ou diminuição da motivação do estudante durante o curso, nas sugestões para inserção de disciplinas, e nos conselhos direcionados aos graduandos. As atividades extracurriculares destacam-se como instrumento para manutenção da motivação do aluno e para facilitar sua inserção no mercado de trabalho. Os egressos se inserem no mercado de forma relativamente rápida, com 50% deles começando a trabalhar na área de formação em menos de 6 meses depois de graduados. No entanto, a maior parcela (63%) recebe menos do que o piso salarial do engenheiro. As médias salariais são maiores entre os egressos com maior experiência. Os resultados contribuem para discussões sobre ensino da Engenharia Ambiental, no intuito de promover a formação de profissionais mais bem preparados e seguros para o enfrentamento profissional.Item Antibiotic consumption in developing countries defies global commitments : an overview on Brazilian growth in consumption.(2020) Castro, Paulo Bernardo Neves e; Rodrigues, Daniel Aparecido da Silva; Roeser, Hubert Mathias Peter; Santiago, Aníbal da Fonseca; Afonso, Robson José de Cássia FrancoFaster 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.Item Desempenho energético e tratamento de água residuária em fotobiorreator contínuo iluminado artificialmente.(2020) Oliveira, Raquel Gomes de; Vassoler, Fábio; Santiago, Aníbal da FonsecaThe use of Light Emitting Diodes (LEDs) as a light source has several advantages: high efficiency, long lifetime and low energy consumption. LEDs can be obtained in the lighting of photobioreactors for the treatment of wastewater. Cleaning removing organic matter, nutrients and pathogens. Most of the researches found in the literature make use of laboratory scale photobioreactors (1L) generally and operated in batch. Despite the low energy consumption of LEDs, its use for continuous photobioreactors is questioned, since the energy performance for these systems has not yet been evaluated. Microalgae are cultivated in photobioreactors and, in addition to promoting wastewater treatment, their biomass can be reused to generate different bioproducts. This research evaluated the efficiency of an open LED-illuminated photobioreactor, simulating the operation of a High Rate Lagoon (LAT) in the treatment of synthetic wastewater and also evaluated the energy aspect as a function of artificial lighting. The system was operated in continuous regime under hydraulic detention time (TDH) of 7 days and luminous intensity of 815 μE.m-2.s-1. The microalgae biomass productivity was 6.80 ± 1.9 g.d-1.m-2 and the net oxygen production was 0.83 g.L-1. The stability and efficiency system in the removal of organic matter, represented by the Chemical Oxygen Demand (COD), with 90.3 ± 1.7% of removal. However, high values of energy consumption indicators for wastewater treatment were obtained, with 368.8 kWh / kg COD removed, 287 kWh.m-3 and 51.66 kWh (hab.d) -1.Item Content analysis of dam break studies for tailings dams with high damage potential in the Quadrilátero Ferrífero, Minas Gerais : technical weaknesses and proposals for improvements.(2020) Paiva, Camilla Adriane de; Santiago, Aníbal da Fonseca; Prado Filho, José Francisco doTailings dams are civil structures that have an intrinsic potential risk of failure that, if poorly managed or neglected, can lead to severe societal, environmental, and economic damage. Studies of dam breaks make it possible to anticipate these damages and plan appropriate contingency actions for critical situations. In this context, the present work presents the analysis of 86 dam break studies of mining tailings dams in the important Brazilian mineral province called the Quadrilátero Ferrífero, or Iron Quadrilateral, in the state of Minas Gerais, Brazil. The analysis involved verifying whether the studies complied with legal requirements, met international guidelines, and addressed the minimum parameters reported as critical in the literature. We found that all studies analyzed present these components: hydrological studies, the defnition of the failure mode and rupture hydrograph, and propagation of the food wave and mapping of the efects of the rupture in the valley downstream of the dam structure. However, the dam break studies showed defciencies, such as the weakness of the hydrological studies, lack of specifc criteria on the volume of tailings that are supposed to mobilize in a possible rupture, and the failures to consistently model tailings as non-Newtonian fuids. These defciencies found in the dam break studies present in Emergency Action Plan afect the predictive capacity of the rupture models and thus the accuracy of the food maps they generate, negatively infuencing preparation actions in an eventual emergency. In the absence of guidelines and the regulation about the minimal content of the dam breach studies, we suggest that a possibility for solving this defciency in the short run is to have technically trained professionals from inspection and control agencies audit the content of the dam break studies.Item Biodegradation of sulfamethoxazole by microalgae-bacteria consortium in wastewater treatment plant effluents.(2020) Rodrigues, Daniel Aparecido da Silva; Cunha, Camila Cristina Rodrigues Ferreira da; Freitas, Mylena Gomes; Barros, André Luis Corrêa de; Castro, Paulo Bernardo Neves e; Pereira, Andressa Rezende; Silva, Silvana de Queiroz; Santiago, Aníbal da Fonseca; Afonso, Robson José de Cássia FrancoSulfamethoxazole (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 inWWTP effluent. Thus, further studies to removal ARG from WWTP effluent are needed.
- «
- 1 (current)
- 2
- 3
- »