Electro-reactor for the removal of PPCPs and microorganisms from effluent: feasibility assessment

A visão da água residual tem vindo a mudar ao longo dos anos, à medida que as estações de tratamento de águas residuais (ETAR) começaram a ser consideradas fontes de recursos valiosos que podem ser recuperados. O uso de água residual tratada para fins não-potáveis como irrigação agrícola representa uma opção viável, capaz de dar resposta a situações de escassez hídrica permitindo tirar pressão na exploração de fontes de água doce. No entanto, a água residual tratada pode possuir riscos químicos e microbiológicos, visto que as tecnologias de tratamento secundário e terciário atualmente utilizadas não permitem atingir uma remoção completa de contaminantes emergentes, como fármacos e produtos de cuidado pessoal. Tecnologias electrocinéticas constituem soluções para o tratamento de água residual para fins de reutilização. A presente dissertação explora a aplicação do processo electrocinético num reator electroquímico para estudar a degradação de cinco compostos orgânicos emergentes: cafeína (CAF), sulfametoxazol (SMX), carbamazepina (CBZ), diclofenaco (DCF) e oxibenzona (OXY). De forma complementar, o efeito do campo elétrico na comunidade microbiológica total do efluente foi avaliado através da contagem de unidades formadoras de colónias que cresceram em meio de agar dextrose de batata, passadas 24 h. Os reatores foram dopados com a mistura de contaminantes com uma concentração de 0.2 mg/L, e foi aplicada uma densidade de corrente fixa de 8 mA/cm² entre elétrodos de óxido de metal misto. No primeiro conjunto de experiências, o processo electrocinético foi aplicado em efluente desinfetado por radiação UV-C à escala laboratorial e três tempos de degradação foram testados: 2 h, 4 h e 6 h. A electrodegradação variou entre 17 ± 6% para CAF após 2 h de tratamento electrocinético, tendo o SMX ficado abaixo do limite de deteção do método, ao fim de 4 h de tratamento. Microrganismos totais cultiváveis do efluente foram reduzidos em cerca de 1.0 unidade logarítmica (Redução em 90%), no primeiro conjunto de experiências. No segundo conjunto de experiências, realizadas em efluente fresco e pelo período de 6 h, verificou-se uma maior inativação dos microrganismos totais cultiváveis, até 3.7 unidades logarítmicas (Redução em 99.98%). Testou-se em paralelo a fotólise por meio de UV-C dos compostos como termo de comparação com o processo eletrocinético. Electrodegradação em efluente fresco permitiu obter para SMX e OXY degradações superiores a 95%. Tanto os fármacos e os produtos de cuidado pessoal em estudo como os microrganismos presentes no efluente podem ter sofrido oxidação anódica direta e oxidação indireta por espécies intermédias formadas em meio aquoso. Ao permitir remover PPCPs e microrganismos, o processo eletrocinético provou ser viável enquanto tecnologia de remediação e desinfeção para efluente secundário de ETAR.The vision of wastewater has been changing over the years, as wastewater treatment plants (WWTPs) are now considered supplies of valuable resources that can be recovered. The use of reclaimed water for non-potable uses such as agriculture irrigation, represents a viable option capable of dealing with water scarcity and allowing to alleviate the exploration of freshwater supplies. However, reclaimed water may enclose chemical and microbiological risks, as the currently used secondary and tertiary treatment technologies do not allow a complete removal of emergent contaminants, such as pharmaceuticals and personal care products (PPCPs). Electrokinetic (EK) technologies are available solutions for wastewater treatment aiming reclamation purposes. This dissertation explores the application of the EK process in one-compartment (1c-cell) electrochemical reactor to study the degradation of five target emergent organic contaminants (EOCs): caffeine (CAF), sulfamethoxazole (SMX), carbamazepine (CBZ), diclofenac (DCF) and oxybenzone (OXY). In addition, the effect of the electric field generated by the low-level direct current (DC) in the effluent total microbial community was also assessed by performing counts of colonies forming units grown in potato dextrose agar media after 24 h of incubation. Reactors were spiked with a mixture of the target PPCPs at a concentration of 0.2 mg/L and a fixed current density of 8 mA/cm² was applied between mixed metal oxide electrodes. In Set 1, the EK process was applied in bench scale UV-C treated effluent and three treatment times were tested: 2 h, 4 h and 6 h. Electrodegradation ranged from 17 ± 6% for CAF after 2 h of EK treatment, to removal below the method detection limit for SMX after 4 h of EK treatment. Total culturable microorganisms were reduced by ≈ 1.0 Log10 unit (90% removal), in Set 1. In Set 2 experiments, performed in fresh effluent and for a period of 6 h, total culturable microorganisms achieved a higher inactivation, up to 3.7 Log10 units (99,98% removal). UV-C photolysis of PPCPs was also tested in Set 2, in comparison to EK treatment. Electrodegradation of PPCPs in fresh effluent was higher than 95% for both SMX and OXY. Both PPCPs and total microorganisms from secondary effluent can suffer direct anodic oxidation and indirect oxidation by generated intermediate species in aqueous media. By allowing PPCPs and microorganisms removal, the EK process proved to be a viable remediation and disinfection technology for secondary effluent from WWTPs

Phenotypic Architecture and Genetic polymorphims Associated with Social Behaviour in Zebra fish

"Social behaviour is fundamental for the survival and reproduction of organisms, and most animals are social to some degree. It is generally recognized that many neuropsychiatric diseases are associated with some form of social deficit or are accompanied by social impairments. There is also evidence that actual and perceived social isolation are both related with increased mortality risk. Given that social behaviour is central in both humans and other animals’ lives, many researchers with different backgrounds have been actively engaged in the challenge of understanding the nature of this highly complex and dynamic phenomenon. Social behaviour that independently evolved multiple times across animals is an extremely diverse behavioural category, influenced by multiple factors (genes, hormones, environment, ecology, development, life history trait, etc.) requiring a multidisciplinary approach, integrative analysis and standardized terminologies. However, despite its great diversity (both between and within species), there are similarities namely at mechanistic and functional level, which allows organizing social behaviours in functional modules, similar to those used in gene ontology categories.

Olive mill wastewater: a suitable medium for lipase production by yeasts

Fundação para a Ciência e a Tecnologia (FCT

Comparison of batch and fed-batch lipase production from olive mill wastewater by Yarrowia lipolytica and Candida cilindracea

Olive mill wastewater (OMW) is a liquid waste that results in large amounts from the olive oil manufacturing industry. The quality and quantity of OMW constituents are dependent of many factors, such as olives type and maturity, climatic conditions and region of origin, cultivation methods, and technology used for oil extraction1. From the 3-phases centrifugation process around 1.6 cubic meters of OMW per ton of olives processed are generated. These liquid wastes present an environmental problem and many solutions have been proposed for it, such as its use as culture medium for different lipolytic yeast strains (Gonçalves et al, 2009; Lopes et al, 2009). The aim of this work is the comparison of batch and fed-batch mode of operation for the lipase production and the OMW degradation by two strains, Yarrowia lipolytica W29 and Candida cylindracea CBS 7869. OMW collected from 3-phase continuous olive mills were used (COD of 30 to 261 g/L). OMW used without dilution was supplemented with ammonium chloride and yeast extract proportionally to the COD values. Batch and fed-batch cultures were conducted in a fermenter of 2 L of capacity at pH 7.2, 500 rpm, with constant or variable aeration rate for batch or fed-batch operation, respectively. Batch operation was more adequate to lipase production than fed-batch for both strains but the difference was more significant for Candida cylindracea that revealed to be the most efficient strain for lipase production. However, the final media of the fed-batch cultures presented lower values of COD and sugars indicating a higher level of organic matter degradation

Biotechnological valorization of olive mill wastewaters

Tese de doutoramento em Química e Engenharia BiológicaMediterranean countries are known to have favorable conditions for olive oil production. The three-phase extraction technology demands the addition of hot water to the process, and olive oil, olive cake and olive mill wastewater (OMW) are produced. An approach for using this waste as a renewable resource is of greater interest. Accordingly, the present investigation aims the OMW valorization, by producing high-value compounds (lipase and methane) while degrading this waste. Thus, the research work presented in this thesis essentially describes a study about an integrated process, where the effluents are firstly submitted to a lipase producing aerobic fermentation, followed by an anaerobic degradation process, to produce methane. This work is of great interest, since Portugal is one of the world leading producers of olive oil, with crescent production values from campaign to campaign, in the last years. This work was started with a study about the major problem attributed to the olive mill wastewaters (OMW), the phenolic compounds toxicity. These experiments showed that the nonconventional yeasts Y. lipolytica, C. rugosa and C. cylindracea are able to grow in different phenolic compounds, usually found in OMW. This was later confirmed in bioreactor batch experiments with OMW-based media, where the studied yeasts, not only were capable of achieving similar cell growth, to glucose synthetic media, but also to highly consume the existing and analyzed phenolic compounds. The experiments on batch fermentations, with OMW-based media, were then performed in Erlenmeyer baffled flasks, in order to study the effect of ammonium, cell and surfactant addition as well as to investigate the use of different yeast strains; Candida rugosa (PYCC 3238 and CBS 2275), Candida cylindracea CBS 7869 and Yarrowia lipolytica (CBS 2073, W29 ATCC 20460 and IMUFRJ 50682); and different non-diluted OMW. C. cylindracea was the best strain concerning the effluent degradation. After preliminary tests, a study of optimal batch and fed-batch conditions was performed in bioreactor, using Candida rugosa CBS 2275, Candida cylindracea CBS 7869 and Yarrowia lipolytica W29 ATCC 20460. It was confirmed that C. cylindracea CBS 7869 was the best lipase-producing yeast (6 U mL-1). However, using a fed-batch strategy, with cell pre-growth directly on the bioreactor, C. rugosa CBS 2275 was the strain that obtained the best values of lipase (17 U mL-1); achieving at the same time, a significant effluent degradation (64 % of COD, 27% of phenolics and 77% of total lipids). Anaerobic biodegradability tests showed that the aerobic treatment had a positive effect on the anaerobic degradation of the OMW. Best results were achieved for the initial concentration of 5 g COD-treated OMW L-1, where 78% of the COD added was recovered as methane. Furthermore, when the COD degradation in the aerobic step was higher, even better results were possible to achieve, with a faster conversion of COD to methane. The obtained results demonstrates that the olive mill wastewaters (OMW) are becoming a competitive and valuable growth medium in fermentation processes and also the potential application of non-conventional lipolytic yeasts for OMW valorization, for biomass and enzymes production. This treatment was successful to detoxify the effluent, having a very positive effect in the anaerobic digestion. The utilization of this valorization process will possibly have a positive impact on the environmental problem of OMW management.Os países que envolvem o Mediterrâneo são conhecidos pelas suas condições favoráveis para a produção de azeite. A tecnologia de extracção de azeite com o sistema em contínuo de 3 fases exige a adição de água quente ao processo, o que dá origem à produção de azeite, águas ruças (OMW) e bagaço. A utilização deste efluente (águas ruças) como um recurso renovável apresenta-se como uma abordagem de elevado interesse, a este problema. Deste modo, o presente trabalho de investigação tem como finalidade a valorização das águas ruças, com produção de produtos de elevado interesse industrial (lipase e metano) enquanto se diminui a carga poluente do resíduo. Assim, o trabalho de investigação apresentado nesta tese descreve essencialmente o estudo de um processo integrado, onde os efluentes são primeiramente submetidos a uma fermentação aeróbia com produção de lipase, à qual se segue um processo de degradação anaeróbia com produção de metano. Este trabalho é de elevado interesse, dado que Portugal está entre os líderes mundiais de produção de azeite, com crescentes valores de produção de campanha para campanha, nos últimos anos. Assim, este trabalho foi iniciado com um estudo focado no problema mais importante associado às águas ruças, a toxicidade dos compostos fenólicos. Estes ensaios mostraram que as leveduras não-convencionais Y. lipolytica, C. rugosa e C. cylindracea são capazes de crescer nos diferentes compostos fenólicos, que frequentemente constituem as águas ruças. Estes resultados foram mais tarde confirmados em bioreactor, onde as referidas leveduras não só foram capazes de crescer, tanto ou até melhor ao que crescem em meio de glucose, como também foram capazes de consumir uma parte considerável de cada composto fenólico, acompanhado ao longo das fermentações. Foram então iniciados os ensaios em descontínuo em matrazes utilizando meio de águas ruças, de modo a fazer um estudo preliminar sobre o efeito da adição de amónio, surfactante e a da concentração de células, bem como o efeito do uso de diferentes leveduras, nomeadamente Candida rugosa (PYCC 3238 e CBS 2275), Candida cylindracea CBS 7869 e Yarrowia lipolytica (CBS 2073, W29 ATCC 20460 e IMUFRJ 50682) e diferentes amostras de águas ruças não diluídas. Foram seleccionadas algumas condições e a C. cylindracea foi a melhor levedura no que diz respeito à degradação do efluente. Depois destes testes preliminares, estudos sobre as condições óptimas a utilizar em descontínuo e semicontínuo foram efectuados em bioreactor, utilizando Candida rugosa CBS 2275, Candida cylindracea CBS 7869 e Yarrowia lipolytica W29 ATCC 20460. Concluiu-se que a C. cylindracea CBS 7869 é a melhor produtora de lipase em fermentações em descontínuo (6 U mL-1), no entanto, utilizando o modo semi-contínuo, com pré-crescimento das células directamente no reactor a C. rugosa CBS 2275 surge como a melhor levedura produtora de lipase, com 17 U mL-1, e com óptimos valores de degradação do efluente (64 % de CQO, 27% de compostos fenólicos totais e 77% dos lípidos totais). Os testes de biodegradabilidade anaeróbia demonstraram que a etapa de tratamento aeróbio que o antecede tem um efeito positivo. Em ensaios posteriores, foram obtidos melhores resultados para a concentração inicial de 5 g L-1 CQO de águas ruças tratadas, com 78 % de conversão do CQO em metano. Mais, verificou-se que quanto melhor é a degradação de CQO na etapa aeróbia do processo integrado, melhores foram os resultados na etapa seguinte, com uma conversão de CQO em metano mais rápida. Os resultados obtidos demonstram que as águas ruças se estão a tornar num meio de crescimento competitivo e importante, mas também o potencial das leveduras lipolíticas não convencionais nos processos fermentativos, para a valorização de águas ruças, com produção de enzimas e biomassa. O sucesso destes processos, na posterior etapa de digestão anaeróbia teve um efeito bastante positivo. A utilização deste processo integrado de valorização de águas ruças poderá assim ter um impacto benéfico para a resolução do problema relacionado com a gestão ambiental das águas ruças

Integrated process for the production of lipase and methane from olive mill wastewaters

The continuous system for olive oil production can be operated by three and two-phase extraction technologies, diverging in the water supplies. The three-phase extraction process has a slightly better yield, leading to less amount of olive cake but a significant production of olive mill wastewater (OMW). The aim of the present work is the OMW valorization by producing high-value compounds while degrading this waste. The effluents are submitted to a lipase producing aerobic fermentation that contributes for a partial OMW degradation, followed by an anaerobic methanogenic degradation process. The aerobic treatment, with production of lipase, is useful for a better yield of methane production. The lipase produced on the aerobic step had loss some activity from 60% to 95%. Best results were achieved for 5 g OMW COD L-1 in terms of methane production (78% of methanisation) and lipase activity decay (60%)

A wolf in sheep’s clothing: when a stroke is not a stroke, and how comprehensive speech and language therapy assessment and intervention can help to set the alarm

A 70-year-old male patient, who was diagnosed with human immunodeficiency virus (HIV) in 2001 and did not undergo antiretroviral therapy, was admitted two months after the onset of left cortical-subcortical ischemic stroke, with involvement of the corona radiata and the left thalamus. As a consequence of this vascular event, he suffered aphasia, severe dysarthria, dysphagia, and right hemiparesis. The patient took part in a rehabilitation program at a rehabilitation centre for neurological diseases with a specialised interdisciplinary rehabilitation team. He underwent speech therapy intervention with a frequency of 2-3 hours per day. Despite the intensity of the program, there was a decline in his clinical and functional status during hospitalisation, with decreased capacity to swallow and communicate (either because of the exacerbation of the aphasia, or due to the worsening of dysarthria and apraxic features). Due to this global deterioration, additional imaging, as well as serological and aetiological examination was performed, which led to a diagnosis of progressive multifocal leukoencephalopathy in the context of HIV1 infection. Antiretroviral therapy was administered to reverse the symptoms. This case illustrates the relevance of clinical disclosure for the establishment of appropriate functional prognoses and discharge planning. It also shows that the initial clinical features can be misleading and can lead to concealment of the real aetiology, as well as delays in appropriate treatment, especially in multipathology patients

Application of non-conventional yeasts for olive mill wastewaters valorization

The olive oil consumed worldwide is mainly produced in Mediterranean countries. Portugal is one of the ten major producers. Pressing and continuous (three- or two-phase) are the most important extraction processes used in olive oil production. A large amount of a liquid waste, called Olive Mill Wastewater (OMW), is generated to a three-phase decanter extraction process. This effluent causes serious environmental problems due to its high lipid content, chemical oxygen demand (COD) and dark colour. Moreover the phytotoxicity of the OMW can be attributed to the phenolic compounds [1]. In fact, the olive pulp is very rich in phenolic compounds and approximately 53 % is lost in the OMW [2]. Due to the seasonality of olive oil production the OMW treatment process should be flexible enough to operate in a non-continuous mode. Besides, the olive mills are small enterprises, scattered around the olive production areas, making individual on-site treatment options unaffordable [3]. The OMW use as a resource to be valorised is an approach of great interest. It is widely posited that several lipolytic yeast species are able to grow in OMW media, consume the organic material and, simultaneously, produce biomass and other valuable products. The aim of the present study is the valorisation of distinct OMW by producing high-value compounds (such as biomass and lipase), while degrading this waste. The OMW were collected from different olive mills from the north of Portugal and 6 yeasts of Candida rugosa, Candida cylindracea and Yarrowia lipolytica were used. All strains were capable to grow on OMW based medium, without dilution, despite the low effectiveness of phenolic compounds degradation. Furthermore the yeast cells were able to consume almost all the sugars present in the media and significantly reduce COD. The process conditions were optimized in order to achieve the highest values of lipase activity. The strains were also selected according to its efficiency, and three of six strains were chosen: C. cylindracea CBS 7869, Y. lipolytica W29 (ATCC 20460) and C. rugosa CBS 2275. [1] Lanciotti, R. et al., Bioresour. Technol. (2005) 96:317 [2] Rodis, P.S. et al., J. Agric. Food. Chem. (2002) 50:596 [3] Paraskeva, P., Diamadopoulos, E., J. Chem. Technol. Biotechnol. (2006) 81:1475.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/27915/200