Sorção e biodegradação do 17-alfa-etinilestradiol e do diclofenaco : estudo da influência da vazão de aeração aplicado ao processo de biorreator com membranas

A ocorrência de fármacos em águas superficiais e residuais é, atualmente, um grande desafio para a comunidade científica, visto que as Estações de Tratamento de Efluentes convencionais não são projetadas visando à remoção desses micropoluentes. O processo de Biorreatores com Membrana (MBR) tem se mostrado uma alternativa viável ao tratamento convencional para o aprimoramento da remoção de produtos farmacêuticos de efluentes industriais e domésticos. No entanto, ainda existem questões não resolvidas, resultados contraditórios e algumas lacunas não estudadas a respeito, como a influência da intensidade da aeração do MBR na remoção desses microcontaminantes. Nesse contexto, para contribuir com as pesquisas na área, este trabalho avaliou o efeito da vazão de aeração nos mecanismos de sorção e biodegradação dos fármacos emergentes 17-alfaetinilestradiol (EE2) e diclofenaco (DCF) em uma planta piloto de MBR aeróbio, correlacionando-os com as suas propriedades físico-químicas. Utilizou-se três vazões de aeração distintas para os experimentos, 2, 5 e 8 L min-1 e os fármacos foram analisados por extração em fase sólida e cromatografia líquida de alta eficiência. No lodo, foram realizados ensaios de granulometria a laser, teor de sólidos e sedimentabilidade. Os resultados demonstraram remoções entre 73 e >85 % para o DCF e entre 81 e >99 % para o EE2, indicando os mecanismos de sorção no lodo e biodegradação aeróbia como predominantes na remoção desses contaminantes. Os resultados de sorção no lodo inativado quimicamente indicaram o alto potencial de sorção do EE2 (78 - 95 %) quando comparado ao DCF (23 - 43 %), o que foi atribuído à sua maior hidrofobicidade. As maiores vazões de aeração favoreceram a sorção do DCF e EE2 o que pode ser atribuído a alterações estruturais dos flocos do lodo, como menor tamanho de partícula e maior dispersão. Por outro lado, o efeito da aeração na biodegradação dos fármacos não foi tão pronunciado e conclusivo; acredita-se que outros parâmetros operacionais, como a razão alimento/microrganismo e os tempos de retenção hidráulica e celular, tenham agido sinergicamente, impedindo a avaliação da vazão de ar isoladamente. Os resultados sugerem o efeito positivo do aumento da intensidade de aeração na remoção dos fármacos estudados, sendo necessário avançar nas pesquisas na área, inclusive no que diz respeito à viabilidade econômica, considerando os custos operacionais com a aeração nos processos de MBRs.The occurrence of pharmaceuticals in surface and wastewater is currently a major challenge for the scientific community, since conventional Wastewater Treatment Plants are not designed to remove these micropollutants. Membrane Bioreactor (MBR) process has been shown as a viable alternative to conventional treatment for improving the removal of pharmaceutical products from industrial and domestic effluents. However, there are issues still unresolved, contradictory results and some gaps not studied, such as the influence of MBR aeration intensity on the removal of these microcontaminants. In this context, to contribute to research in the area, this work evaluated the effect of aeration flow rate on the sorption and biodegradation mechanisms of the emerging drugs 17-alpha-ethinylestradiol (EE2) and diclofenac (DCF) in an aerobic MBR pilot plant, correlating them with its physicochemical properties. Three different aeration flow rates were used for the experiments, 2, 5 and 8 L min-1 and the pharmaceuticals were analyzed by Solid Phase Extraction and High Performance Liquid Chromatography. In the sludge were carried out Laser Particle Size Analyzer, solids content and sedimentability tests. The results showed removals between 73 and >85% for DCF and between 81 and >99% for EE2, indicating the mechanisms of sorption in sludge and aerobic biodegradation as predominant in the removal of these contaminants. The sorption results in chemically inactivated sludge indicated the high sorption potential of EE2 (78 - 95 %) when compared to DCF (23 - 43 %), which was attributed to its greater hydrophobicity. The higher aeration flow rates favored the sorption of DCF and EE2 which can be attributed to structural alterations in the sludge flocs, such as smaller particle size and greater dispersion. On the other hand, the effect of aeration on the biodegradation of drugs was not as pronounced and conclusive; It is believed that other operational parameters, such as the food/microorganism ratio and the sludge and hydraulic retention times, acted synergistically, preventing the assessment of the air flow in isolation. The results suggest the positive effect of increasing the intensity of aeration in the removal of the pharmaceuticals studied, making it necessary to advance in research in the area, including with regard to economic feasibility, considering the operating costs with aeration in MBR processes

Electrochemical and mechanical behavior of UV curing paint on hybrid films modified with polyethyleneglycol plasticizer applied on tinplate

The objective of this work is to coat tinplate with a hybrid film obtained from a sol-gel process constituted by the alkoxide precursor tetraethoxysilane (TEOS) and 3-trimethoxysilylpropyl methacrylate (TMSM), with the addition of cerium nitrate (0.01 M) and polyethyleneglycol plasticizer (20 g.L-1) to the sol formulation. The films were obtained by dip-coating, applying one and two layers and curing them at different temperatures (60°C and 90°C) for 20 minutes, and adhering UV curing paint to each film respectively. The results showed that the double layered hybrid film obtained at 60°C had a higher layer of thickness and the best performance in the electrochemical assays, in other words, higher resistance to corrosion. Furthermore, in studies following the application of UV coating, the hybrid-film monolayer cured at 60°C wich had an organic coating of cured UV applied to it, achieved a performance similar to that of the pretreated alkyd greenhouse currently used in the metal packaging industry

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved