Transport mechanism in ionic liquid membranes and the study of thiomersal biodegradation

The initial goal of this work was the development of a supported liquid membrane (SLM) bioreactor for the remediation of vaccine production effluents contaminated with a highly toxic organomercurial – thiomersal. Therefore, two main aspects were focused on: 1) the development of a stable supported liquid membrane – using room temperature ionic liquids (RTILs) – for the selective transport of thiomersal from the wastewater to a biological compartment, 2) study of the biodegradation kinetics of thiomersal to metallic mercury by a Pseudomonas putida strain. The first part of the work focused on the evaluation of the physicochemical properties of ionic liquids and on the SLMs’ operational stability. The results obtained showed that, although it is possible to obtain a SLM with a high stability, water possesses nonnegligible solubility in the RTILs studied. The formation of water clusters inside the hydrophobic ionic liquid was identified and found to regulate the transport of water and small ions. In practical terms, this meant that, although it was possible to transport thiomersal from the vaccine effluent to the biological compartment, complete isolation of the microbial culture could not be guaranteed and the membrane might ultimately be permeable to other species present in the aqueous vaccine wastewater. It was therefore decided not to operate the initially targeted integrated system but, instead, the biological system by itself. Additionally, attention was given to the development of a thorough understanding of the transport mechanisms involved in the solubilisation and transport of water through supported liquid membranes with RTILs as well as to the evaluation of the effect of water uptake by the SLM in the transport mechanisms of water-soluble solutes and its effect on SLM performance. The results obtained highlighted the determinant role played by water – solubilised inside the ionic liquids – on the transport mechanism. It became clear that the transport mechanism of water and water-soluble solutes through SLMs with [CnMIM][PF6] RTILs was regulated by the dynamics of water clusters inside the RTIL, rather than by molecular diffusion through the bulk of the ionic liquid. Although the stability tests vi performed showed that there were no significant losses of organic phase from the membrane pores, the formation of water clusters inside the ionic liquid, which constitute new, non-selective environments for solute transport, leads to a clear deterioration of SLM performance and selectivity. Nevertheless, electrical impedance spectroscopy characterisation of the SLMs showed that the formation of water clusters did not seem to have a detrimental effect on the SLMs’ electrical characteristics and highlighted the potential of using this type of membranes in electrochemical applications with low resistance requirements. The second part of the work studied the kinetics of thiomersal degradation by a pure culture of P. putida spi3 strain, in batch culture and using a synthe tic wastewater. A continuous ly stirred tank reactor fed with the synthetic wastewater was also operated and the bioreactor’s performance and robustness, when exposed to thiomersal shock loads, were evaluated. Finally, a bioreactor for the biological treatment of a real va ccine production effluent was set up and operated at different dilution rates. Thus it was possible to treat a real thiomersal-contaminated effluent, lowering the outlet mercury concentration to values below the European limit for mercury effluent discharges.

Freshwater arsenic detoxification through selenium-enriched food supplements. A proteomic approach

Dissertação apresentada para a obtenção do grau de doutor em Bioquímica pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Development of thermoresponsive (polysulfone/polyacrylonitrile) - based membranes for bioseparation processes

Mestrado integrado em Engenharia Química e Bioquímica

Development of 2-oxazoline-based hydrogels and porous polyester microparticles in scCO2

Thesis submitted to Faculdade de Ciências e Tecnologia from Universidade Nova de Lisboa in partial fulfillment of the requirements for the obtention of the degree of Master of Science in Biotechnology

Evaluation of thermometers for ear temperature measurement at the wards in a university hospital

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Development of chitosan-based microparticles for pulmonary drug delivery

Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica

Quantification and characterization of the phenolic compounds of kenaf leaves

Dissertation for the Master Degree in Technology and Food Security

Heavy metal contamination in seafood and consumer exposure in the Gulf Cooperation Council

Dissertação para obtenção do Grau de Mestre em Tecnologia e Segurança Alimentar

O contrato de Project Finance

Currently, Angola portrays a notorious economic growth and due to recent innovative legislations, it has become the major investment attracting pole, especially in Sub-Saharan Africa, having, thus, an extraordinary potentiality for a rapid and sustainable development, likely to place her in outstanding positions in the world economic ranking. Yet, such economic growth entails demanding levels of intensive investment in infrastructure, what has been reported of the Angolan Government to be unable to respond to, save if recurring to very high index of external debt, poisoning, in this way, the future budgeting of the country. Due to these infrastructure investment shortages, the cost of production remains highly onerous and the cost of life extremely unaffordable. On this account, the current study disserts about the contract of Project Finance; an alternative finance resource given as a viable solution for the private financing of infrastructure, aiming to demonstrate that such contractual figure, likewise the experience of several emerging economies and others, is a contract bid framework to take into account in today’s world. It refers to a financing technique – through which the Government may satisfy a common need (for example, the construction of a public domain or public servicing), without having to pay neither offer any collateral – based on a complex legal-financial engineering, arranged throughout a coalition of typical and atypical agreements, whereby it is mandatory to look back at the basic concepts of corporate law. More than just a simple financial study, the dissertation at stake analyses the nature and legal framework of Project Finance, which is a legally atypical and innominate contract, concluding that there is a relevant need for regulating and devoting a special legal regime in the Angolan jurisdiction for this promising legal form in the contemporary corporate finance world.