Tratamento de efluente de planta de produção de ácido lático

O ácido lático, ou ácido 2-hidroxipropiônico, pode ser produzido por uma rota química ou bioquímica, sendo comercialmente importante em diferentes setores da indústria. A planta piloto que serviu de base para este estudo produz ácido lático por fermentação utilizando Lactobacillus sp empregando glicose, oriunda da mandioca, como substrato. O efluente gerado por esta planta na etapa de produção do ácido lático apresenta elevada concentração de matéria orgânica (DQO = 140000 mg/L) e deve ser corretamente tratado antes de sua disposição em um corpo hídrico. O presente projeto avaliou o tratamento biológico anaeróbio deste efluente, e a possibilidade de uso do metano gerado como fonte de energia na planta industrial. Como o efluente bruto apresentava elevada quantidade de sólidos residuais (principalmente biomassa), um pré-tratamento foi realizado por ensaios de coagulação/floculação seguidos de sedimentação em equipamento Jar Test empregando PAC (policloreto de alumínio) e Zetag (floculante catiônico) a diferentes concentrações e valores de pH. Este pré-tratamento apresentou reduções de DQO muito baixas (até 24%). Assim, ensaios de biodegradabilidade anaeróbia foram realizados em batelada em frascos tipo penicilina de 100 mL com o efluente bruto para valores de DQO inicial de até 16000 mg/L. Nestes ensaios verificouse que o efluente é biodegradável por via anaeróbia e que o lodo se adaptou gradualmente aos constituintes do mesmo, apresentando uma atividade metanogênica específica de 79,6 L CH4/kg SVS.d. Dados obtidos nos ensaios de bancada e recomendados na literatura foram empregados no projeto preliminar de um reator UASB em escala plena, chegando-se a um volume de 1425,6 m3, com 70,7 m2 de área, 20,2 m de altura e 9,5 m de diâmetro. Como as dimensões obtidas eram pouco usuais, sugere-se dividir a vazão para quatro reatores operando em paralelo com 356,4 m3, com 30,9 m2 de área, 11,5 m de altura e 6,3 m de diâmetro. A energia obtida na planta industrial com a queima de metano seria de 1,3 x 108 KJ/dia, e esta poderia ser utilizada em uma caldeira operando com 90% de eficiência para gerar 54547,4 kgv/dia

Shifts in the field of the adult education. On training paths for adult educators

In contemporary times the adult education field faces relevant shifts leadingto the emergence of tensions and dilemmas that force its reconfiguration.Therefore, several problems rise in what adult educators’ training is concerned,mainly these induced by the prevalence of certain forms of training.Searching for innovative ways of conceiving and developing adult educatorstraining, the Unit for Adult Education of the University of Minho joined theproject A Good Adult Educator in Europe (AGADE). In this paper, theauthors wish to present six principles by which a disposal of adult educatorstraining can be based on.O campo da educação enfrenta na actualidade importantes desafios que têmlevado ao surgimento de tensões e dilemas que forçam a sua reconfiguração.Neste âmbito, a formação de educadores de adultos também se confrontacom diversos problemas, com destaque para aqueles induzidos pelaprevalência de determinados modos de conceber e entender a formação.Foi na procura de modos alternativos e inovadores de conceber e desenvolvera formação de educadores de adultos que a Unidade de Educação deAdultos da Universidade do Minho participou no projecto A Good AdultEducator in Europe (AGADE). Neste texto, procura-se dar conta da definiçãode seis princípios orientadores da concepção de um dispositivo de formaçãode educadores de adultos

Environmental Performance of a Solid Waste Monetization Process Applied to a Coal-Fired Power Plant with Semi-Dry Flue Gas Desulfurization

Mixing of semi-dry flue gas desulfurization solids and fly-ash from coal-fired power plants results in a solid waste contaminated by calcium sulfite. Therefore, it becomes useless for industry and is often landfilled. To support decision-making on process configurations to monetize this solid residue a gate-to-gate life cycle assessment was performed, considering three scenarios: BASE case – standard 360 MW power plant, CASE I – base plant adopting dry thermal oxidation treatment of spray dryer solids, CASE II ‒ bypass of desulfurization system. Cases I and II allow commercialization of the solid residue as class C fly-ash. Evaluated alternatives were compared based on quantitative potential environmental impacts, using United States Environmental Protection Agency waste reduction algorithm. Based on the results, the BASE case was more aggressive to the environment, due to solid waste production. CASE II increased photochemical oxidation and acidification potentials. CASE I was the more environmentally friendly but demands additional capital and operational expenditure

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Adult education in Portugal: different scenarios and distinct ways of searching for learning and development

This paper follows on from the authors' participation in a project aiming at the characterisation of the practices developed in several European countries called 'Developing Local Learning Centres and Learning Partnerships as Part of Member States Targets for Reaching the Lisbon Goals in the Field of Education and Training. A Study of the Current Situation' (Leiden University, 2005). We now aim to go further as regards the characterisation of the contexts and practices described at the time, seeking to clarify certain issues regarding the history of the organisations involved, the education and training policies either tacitly or explicitly endorsed, the organisational structures adopted and the preferred principles and forms of action. We shall start by pointing out some aspects of adult education policies which have been adopted in the past three decades in Portugal and on the main features and goals of the research; the discussion of the main results make up another part of the paper, which concludes with a review of the main aspects examined

Educação adultos em Portugal: modos de pensar e modos de fazer

Este texto surge na sequência da participação dos autores num projecto dirigido para a caracterização das práticas desenvolvidas em organizações e estruturas orientadas para a educação de adultos, em diversos países europeus (Buiskool et aI., 2005). Agora, procuramos ir mais longe na caracterização dos contextos e práticas então objecto de descrição no panorama português, clarificando aspectos da história das organizações envolvidas, das políticas de educação e formação, tácita ou explicitamente assumidas, das estruturas organizativas adoptadas, dos princípios e formas de acção privilegiados. Começamos por sinalizar alguns aspectos das políticas de educação de adultos que nas últimas três décadas têm sido adoptadas em Portugal; apresentamos, depois, as coordenadas fundamentais do trabalho de pesquisa desenvolvido; a discussão dos principais resultados obtidos constitui o objecto da terceira e quarta partes do artigo que conclui com uma revisão de alguns dos principais aspectos analisados

Technical–Economic Assessment—The Missing Piece for Increasing the Attractiveness of Applied Biocatalysis in Ester Syntheses?

Although the current literature describes significant advances in biocatalytic ester syntheses, few industrial plants worldwide are currently producing esters using biocatalysts. Green and sustainable esters can be obtained via a biocatalytic route, including some operational advantages over conventional syntheses. An analysis of the literature revealed that most articles neglect or describe the economic issues generically, without quantitative information. Scaling-up studies are also scarce in this field. The main disadvantage of biocatalysis using immobilized lipases—their cost—has not been studied at the same level of depth as other technical aspects. This gap in the literature is less intense in enzymatic biodiesel production studies and, despite the lack of a strict correlation, enzymatic biodiesel commercial plants are relatively more common. Preliminary techno-economic assessments are crucial to identify and circumvent the economic drawbacks of biocatalytic ester syntheses, opening the way to broader application of this technology in a large-scale context