10 resultados para Refinery treated effluent


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Dissertation presented to obtain the Ph.D degree in Engineering and Technology Sciences, Biotechnology.

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Dissertation to obtain the degree of Master in Chemical and Biochemical Engineering

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In order to address and resolve the wastewater contamination problem of the Sines refinery with the main objective of optimizing the quality of this stream and reducing the costs charged to the refinery, a dynamic mass balance was developed nd implemented for ammonia and polar oil and grease (O&G) contamination in the wastewater circuit. The inadequate routing of sour gas from the sour water stripping unit and the kerosene caustic washing unit, were identified respectively as the major source of ammonia and polar substances present in the industrial wastewater effluent. For the O&G content, a predictive model was developed for the kerosene caustic washing unit, following the Projection to Latent Structures (PLS) approach. Comparison between analytical data for ammonia and polar O&G concentrations in refinery wastewater originating from the Dissolved Air Flotation (DAF) effluent and the model predictions of the dynamic mass balance calculations are in a very good agreement and highlights the dominant impact of the identified streams for the wastewater contamination levels. The ammonia contamination problem was solved by rerouting the sour gas through an existing clogged line with ammonia salts due to a non-insulated line section, while for the O&G a dynamic mass balance was implemented as an online tool, which allows for prevision of possible contamination situations and taking the required preventive actions, and can also serve as a basis for establishing relationships between the O&G contamination in the refinery wastewater with the properties of the refined crude oils and the process operating conditions. The PLS model developed could be of great asset in both optimizing the existing and designing new refinery wastewater treatment units or reuse schemes. In order to find a possible treatment solution for the spent caustic problem, an on-site pilot plant experiments for NaOH recovery from the refinery kerosene caustic washing unit effluent using an alkaline-resistant nanofiltration (NF) polymeric membrane were performed in order to evaluate its applicability for treating these highly alkaline and contaminated streams. For a constant operating pressure and temperature and adequate operating conditions, 99.9% of oil and grease rejection and 97.7% of chemical oxygen demand (COD) rejection were observed. No noticeable membrane fouling or flux decrease were registered until a volume concentration factor of 3. These results allow for NF permeate reuse instead of fresh caustic and for significant reduction of the wastewater contamination, which can result in savings of 1.5 M€ per year at the current prices for the largest Portuguese oil refinery. The capital investments needed for implementation of the required NF membrane system are less than 10% of those associated with the traditional wet air oxidation solution of the spent caustic problem. The operating costs are very similar, but can be less than half if reusing the NF concentrate in refinery pH control applications. The payback period was estimated to be 1.1 years. Overall, the pilot plant experimental results obtained and the process economic evaluation data indicate a very competitive solution through the proposed NF treatment process, which represents a highly promising alternative to conventional and existing spent caustic treatment units.

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Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Ciência e Sistemas de Informação Geográfica

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Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente – Perfil de Engenharia Sanitária

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Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente – Perfil Gestão e Sistemas Ambientais

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Dissertação para a obtenção do Grau de Mestre em Engenharia e Gestão da Água

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The formulation and use of lime mortars with ceramic particles has, in the past, been a very common technique. Knowledge of such used techniques and materials is fundamental for the successful rehabilitation and conservation of the built heritage. The durability that these mortars have shown encourages the study of the involved mechanisms, so that they may be adapted to the current reality. The considerable amount of waste from old ceramics factories which is sent for disposal might present an opportunity for the production of reliable improved lime mortars. In this paper a number of studies that characterize old building mortars containing ceramic fragments are reviewed. The most important research undertaken on laboratory prepared mortars with several heat treated clays types is presented, specifically with incorporated ceramic waste. Some studies on the pozzolanicity of heat treated clays are examined and the heating temperatures that seem most likely to achieve pozzolanicity are presented. It was verified that some heating temperatures currently used by ceramic industries might correspond to the temperatures that will achieve pozzolanicity.

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RESUMO: Introdução: Uma meta-análise recente demonstrou que uso adjuvante de ácido zoledrónico (AZ) em mulheres pós-menopáusicas com cancro da mama precoce (CM) conduz a redução do risco de morte por CM em 17%. Investigámos o efeito do estado hormonal (pré [PrM] vs pós-menopausa tardia [PoM]) na remodelação óssea e controlo de doença em mulheres com CM e metástases ósseas (MO) tratadas com AZ e quimioterapia (QT). Métodos: Neste estudo de coorte retrospetivo, colhemos variáveis clinico-patológicas e quantificámos o telopéptido N-terminal (NTX) urinário e marcadores tumorais (MT) séricos em mulheres com CM e MO tratadas com QT e AZ. As doentes foram divididas em PrM (<45 anos) e PoM (>60 anos). Endpoints do estudo: variação do NTX, CA15.3 e CEA nos meses 3, 6 e 9, tempo até falência de QT de primeira-linha e sobrevivência. Quando apropriado foram usados os testes de Wilcoxon rank-sum, modelo de efeitos lineares mistos, teste log-rank e modelo de Cox. Resultados: Quarenta doentes foram elegíveis para análise (8 PrM e 32 PoM). Depois da introdução de AZ e QT, os níveis de NTX e MT caíram no coorte global. O perfil de resposta não diferiu entre grupos no mês 3 ou em tempos posteriores (valor-p para interação tempo-estado hormonal no mês 3=0.957). Ademais, o perfil de resposta dos MT também não diferiu entre grupos. O tempo mediano até falência de primeira-linha de QT em PrM e PoM foi de 15.2 e 17.4 meses, respetivamente. Não foi identificada diferença significativa entre grupos, quer em análise univariada quer após controlo para envolvimento visceral (p=0.399 e 0.469, respetivamente). Igualmente, não houve diferenças em termos de sobrevivência. Conclusões: Neste coorte, não foram identificadas diferenças no controlo de NTX ou MT em função do estado menopausico. Igualmente, não foi identificada diferença no tempo até falência de primeira-linha de CT ou sobrevivência.----------- ABSTRACT: Background: A recent meta-analysis showed that the adjuvant use of zoledronic acid (ZA) in postmenopausal women with early breast cancer (BC) leads to a reduction in the risk of breast cancer death by 17%. We investigated the effect of the hormonal status (pre [PrM] vs late post menopause [PoM]) on bone turnover and disease control among women with BC and boné metastases (BM) treated with ZA and chemotherapy (CT). Methods: In this retrospective cohort study, we collected clinicopathologic variables, urinary Nterminal telopeptide (NTX) and serum tumor marker levels from women with BC and BM treated with CT and ZA. Patients were divided in PrM (<45 years) and PoM (>60 years). Study endpoints were NTX, CA15.3 and CEA variation at 3, 6 and 9 months, and time to first-line CT failure and survival. We performed multilevel mixed-effects linear regression models to assess the variation of repeated measures and cox regression models for time to event outcomes. Results: Forty patients were eligible for analysis (8 PrM and 32 PoM). After introduction of ZA and CT, NTX and tumor markers declined in the overall cohort. Response profile was similar between menopausal groups at month 3 and at later time points (p-value for time-hormonal status interaction at month 3=0.957). Furthermore, tumor markers response profile was also equal between groups. Median time to first-line CT failure in PrM and PoM women was 15.2 and 17.4 months, respectively. No significant difference between groups was found, either using a univariate analysis or after controlling for visceral disease involvement (p=0.399 and 0.469, respectively). Likewise, no differences in survival were found. Conclusions: In this cohort, no differences were found in terms of NTX or tumor markers control according to menopausal status. Similarly, no difference in time to first-line CT failure or survival was found.

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Nowadays, a significant increase in chronic diseases is observed. Epidemiological studies showed a consistent relationship between the consumption of fruits and vegetables and a reduced risk of certain chronic diseases, namely neurodegenerative disorders. One factor common to these diseases is oxidative stress, which is highly related with proteins, lipids, carbohydrates and nucleic acids damage, leading to cellular dysfunction. Polyphenols, highly abundant in berries and associated products, were described as having antioxidant properties, with beneficial effect in these pathologies. The aims of this study were to evaluate by proteomic analyses the effect of oxidative insult in a neuroblastoma cell line (SK-N-MC) and understand the mechanisms involved in the neuroprotective effects of digested extracts from commercial and wild blackberry (R. vagabundus Samp.). The analysis of the total proteome by two-dimensional electrophoresis revealed that oxidative stress in SK-N-MC cells resulted in altered expression of 12 protein spots from a total of 318. Regarding some redox proteomics alterations, particularly proteins carbonylation and glutathionylation, protein carbonyl alterations during stress suggest that cells produce an early and late response; on the other hand, no glutathionylated polypeptides were detected. Relatively to the incubation of SK-N-MC cells with digested berry extracts, commercial blackberry promotes more changes in protein pattern of these cells than R. vagabundus. From 9 statistically different protein spots of cells incubated with commercial blackberry, only β-tubulin and GRP 78 were until now identified by mass spectrometry. Further studies involving the selection of sub proteomes will be necessary to have a better understanding of the mechanisms underlying the neuroprotective effects of berries.