On average, 44% of total water abstraction in Europe is used in agriculture. Evidence of water scarcity in Europe is borne out by research that shows increasing strain on water resources in 30% of EU member states. Current research seems to validate the view that wastewater treatment and reuse is a technical opportunity to address the imbalances between agricultural water demand and European water resources in the long term. Currently, just 2.4% of wastewater treatment plant (WWTP) effluents are reused, and thus the water reuse potential in Europe remains high. This document reports on and analyses the performance of a prototype-scale plant installed to treat real wastewater in rural Spain using a Treat & Reuse Membrane Bioreactor (T&R MBR). It shows that the T&R MBR is an improvement on MBR operations due to the fact that it produced a solids-free, nutrient rich and high-quality permeate in which Escherichia Coli was removed to values < 1 ufc/100ml. Furthermore, Biological Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Turbidity and Suspended Solids (SS) were typically lowered to concentrations below the legal limit established in countries such as France, Italy, Spain, Greece, Cyprus and Portugal. Additionally, the system was able to extract nutrients from the wastewater inflow and to retain them in the permeate at 80% and 60% of the Nitrogen (once transformed to Nitrates) and Phosphorous, respectively. These results, combined with the continuing reduction of capital and operating costs for the T&R MBRs, suggest that they are an increasingly cost-effective technology for producing treated effluents suitable for water reuse in agriculture. This study also suggests possible limitations regarding the fate of micro-pollutants during treatment. Nevertheless, the system works efficiently so long as the wastewater input meets the typical composition of raw municipal wastewater with minor contributions of industrial wastewater. This would imply low concentration of trace organic contaminants (TrOCs) and Heavy Metals, as well as slight to moderate salinity (i.e. 0.7-3.0 dS/m). In spite of the fact that the T&R MBR technology can reduce the fresh water and fertilizer consumption of the agriculture sector, this system cannot be implemented in countries where the legislation restricts the reuse of effluents with significant concentrations of Nitrates and Phosphorous (e.g., Germany). Therefore, the present document suggests a set of technical criteria addressing the European challenges regarding water reuse in agriculture.

This research is focused on obtaining an important reduction in greenhouse gas (GHG) emissions resulting from the use of fossil fuels by increasing the efficiency of pre-combustion carbon capture. It examines a new, low-risk, approach that uses conventional water gas shift reactors and acid gas removal technology in a unusual arrangement, within an Integrated Gasification Combined Cycle power plant (IGCC). Timmins (2010) proposed a flowsheet of this nature and it is this flowsheet that is used as the starting point for this research project. Process simulation in UniSim Design R390 is conducted  to validate the viability of such  a flowsheet and to investigate optimal plant configuration. The modelling output is compared to US DOE baseline studies for competing technologies (2010).The physical solvent, Selexol, is used for cardon dioxide (CO2) absorption as recommended by researchers as the most energy efficient amongst the range of physical and chemical solvents investigated. There are mainly two thermodynamic models required to meet all of the needs of this complex process. Most of the process is modelled with the Peng-Robinson equation of state but the Selexol absorber and desorber is modelled using the non-random-two-liquid model  (NRTL) for the liquid phase and the ideal gas law for the vapour phase. A beseline flowsheet model is successfully modelled that could be attached to an IGCC plant to enable it to continue producing electric power whilst capturing 90% of the carbon derived from the fuel. The model is used for process development, and for energy efficiency evaluation. Every major item of capital equipment has been included, modelled and sized to produce a cost analysis and additionallly, the model output was used for a preliminary life cycle analysis (LCA). From the results produced in this study, the proposed process appears to be a feasible, energy-efficient, alternative technology for incorporating carbon capture within an IGCC flowsheet.

The need of understanding the relationship between the physical habitat and ecology in the fluvial systems has become a major issue due to an increasing environmental conciousness but also because of the normativity which demand the achievement of the good status of the water bodies and its ecosystems. Exactly this requirement is prescribed by the European Water Framework Directive (WFD) which have included the hydromorphology as an important aspect of evaluation due to the influence that it has on the ecology of a river system. The hydromorphology gets relevance because it study the system as a whole, involving the interactions between ecology, hydrology and fluvial geomorphology. As a response to the WFD each country of the European Union has developed a method for guaranteeing the compliance of the normativity. Elements of such methods and of international literature are collected for the development of a methodology that fulfill the gaps of the current Colombian water normativity and support the decision making in the environmental planning and impact assessment. This guide for the river morphological restoration in Colombia is a complete hydromorphological analysis of a selected river which main purpose is to make an approach to the general aspects of the river in the macro scale, followed by an assessment in the meso scale in which the river is segmented, classified and the hydromorphological conditions are scored; finally, a simulation is performed for a critical reach, called in this work the “bottle neck” reach. The simulation consists in a hydrodynamics model (or hydromorphodynamics model as optional), its results of depth, velocity and substrate in combination with the preferences of a fish indicator species, are computed in the software CASiMiR and give the habitat suitability in the study area for the simulated conditions. The application of such methodology is applied in a mountainous river reach downstream the Punt da Gall dam in Switzerland for which the hydromorphological aspects in the macro and meso scale are assessed and in the micro scale the habitat distribution of fish indicator species are calculated. The present work is an attempt to apply the habitat simulation as a tool for determining hydromorphological quality, for river restoration activities and for determining minimum habitat conditions when the discharge is regulated. Future investigations include the application in a Colombian river for which the collection of biological data still is a challenge.

In the last years Nonlinear Model Predictive Control (NMPC) has received an increasing attention in academic research due to its ability to achieve optimal process operation of nonlinear processes. NMPC has been applied to several pilot plants; however major obstacles like plant model mismatch and disturbances have to be overcome in order to allow industrial applications. Multi-stage NMPC (MSNMPC) is a robust NMPC approach which achieves optimal process operation under uncertainties of the process model. A complete workflow from simulation studies to real application of MSNMPC has been developed to overcome the mentioned obstacles. However, explicit knowledge from the fields of mathematics, optimization theory, and process control is required. Therefore, efficient methods for evaluation of MSNMPC that support the transition from simulation to application in the real process are required. In this master thesis a module that applies several evaluation methods to offline simulations of MSNMPC is developed. The effectiveness of the module is shown in the case study of an industrial batch polymerization reactor.

Youth suicidality is a worldwide major concern; even more, if a specific population of youth, as young people in the child welfare system, are likely to be at higher risk. Therefore, emerge the need to identify particular characteristics that may be predictors of these suicidal behaviors in order to provide better prevention and intervention programs. Portugal is a country that does not have information regarding youth suicide in care. Seeking to contribute to this matter this study aims to make a profile of young Portuguese people (of 16- and 17- years old) in residential care with suicide attempts, identifying the relation between suicidality and sociodemographic variables, type of placement and maltreatment, mental health problems and risk behaviors. Comparisons of the data gathered were made on adolescents in residential care with suicide attempts and adolescents without it, bivariate analyzes were carried out to identify the difference between samples. Results supported a statistical relationship with physical neglect as a type of maltreatment, and alcohol and drugs abuse as factors that may increase the risk of suicide attempts. Regarding mental health, treatments do not cover the whole population with suicide attempts, with lightly less of half of the adolescents with suicidality not receiving psychiatric treatment. Further analysis is needed to identify if more rigorous mental health treatment might reduce suicidality. Resúmen: La tendencia suicida en los jóvenes es una preocupación importante a nivel mundial; aún más, si una población específica, como aquellos quienes están en el sistema de bienestar, tienen probabilidades de tener riesgos mayores. Por esta razón, surge la necesidad de identificar características particulares de los jóvenes en el sistema de bienestar que puedan predecir comportamientos suicidas con el fin de proporcionar mejores programas de prevención e intervención. Portugal es un país que no tiene información sobre el suicidio juvenil en el sistema de bienestar. Buscando contribuir a esta área, el siguiente estudio pretende hacer un perfil de jóvenes portugueses (de 16 y 17 años) en acogimiento residencial con intentos de suicidio, identificando la relación entre la variable tendencias suicidas y variables sociodemográficas, perfil del acogimiento y tipo de maltrato, problemas de salud mental y comportamientos de riesgo. Se compararon los datos de adolescentes en acogimiento residenciales con intentos de suicidio y adolescentes sin intentos, llevando a cabo análisis bivariados para identificar la diferencia entre las muestras. Los resultados revelaron una relación estadística entre negligencia física como un tipo de maltrato, y abuso de alcohol y drogas como factores que pueden aumentar el riesgo de intentos suicidas. En cuanto a la salud mental, se identificó que los tratamientos no cubren a todos los jóvenes con intentos de suicidio, hallando que no reciben tratamiento psiquiátrico un poco menos de la mitad de los adolescentes con tendencias suicidas. Por esta razón, se considera necesario realizar más análisis para identificar si un tratamiento de salud mental más riguroso podría reducir las tendencias suicidas.

The Passivhaus Standard is a construction concept based on affordably achieving the best indoor conditions with the lowest energy demand. If adopted, it could contribute to fulfil the lack of regulations in energy and comfort performance in Colombian dwellings that the current sustainability laws mandate. The Standard has been applied in warm regions mostly throughout the Mediterranean.This work intended to study its applicability for social housing in tropical climates, specifically four Colombian cities with different average energy demands and number of occupants per household and diverse climatic conditions. The work identified and described a reference building based on an average ‘good practice’ social housing project product of the current Building Regulations. It was modelled in the Passivhaus Planning Package (PHPP) to analyse its performance in the four cities. The results showed that the thermal performance of the building envelope is better than expected due to favourable climatic conditions in most of the cities, although it needs improvements. Even if primary energy demand is lower in the four cities than the maximum allowed by the Standard, it would be considerably high for dwellings without mechanical heating or cooling. The improved models showed that adopting passive strategies according to local climates reduced daily temperature swings and increased indoor comfort. Applying energy efficiency measures such as solar thermal DHW and more efficient fridges and lighting decreased primary energy demand significantly to less than a half of the maximum allowed. The Standard would be applicable in tropical climates even within the budget limitations for social housing in Colombia, although not exactly in the same way as in central Europe. Local circumstances and passive strategies must be taken into account to feasibly achieve the Passivhaus Standard in Colombian social housing.

The growing problem of maintaining socio-economic sustainability in a changing climate has focused attention of a wide range of stakeholders on devising and delivering adaptive responses. A series of IPCC reports have emphasised that the economies of developing countries and particularly the poor would bear the brunt of climate change impacts. Farmers are highly vulnerable because of their high and direct dependency on natural resources, climate-sensitive livelihoods and lack of access to resources that they could rely on to respond successfully to shocks. Microfinance has become an increasingly used and effective tool to respond to major global challenges at the local level, including poverty and climate change. This thesis seeks to analyze the effects that the level of climate change risk and impact has on the willingness of Colombian farmers to invest, through microfinances, in strategies to adapt anticipatively to climate change. The methodology combines experimental economic games, surveys and interviews with farmers who cultivate three different crops: coffee, cocoa and citrus. The findings demonstrate that adaptation decisions depend on climate variability, the cost to implement an adaptation strategy and its benefits to cope with current hazards. Some farmers are risk takers as they prefer to face the risk of losing the harvest rather than pay the adaptation costs. Integrated pest management and beekeeping were strategies preferred under any level of climate variability, while farmers invested in crop diversification and solar dehydrators when facing higher risk of climate change. They were willing to obtain individual and associative microcredits. Microcredits awarded to small farmers in a short period of time enable them to accumulate and manage assets that make them less vulnerable. Microfinance can be more effective when combined with training and bottom-up strategies such as social networks, establishment of partnerships, collective lands and social learning that help farmers to increase their earnings, improve land productivity and promote food security.

Mean sea level rise exposes coasts to increasing risks. For the Caribbean Sea, the regional and local sea-level behaviour is not well known. This study has investigated the sea level behavior in the region at different frequencies during the last century, to provide updated, accurate and useful information to implement coastal adaptation responses to sea-level hazards. Time series from 28 tide-gauges, 18 years of altimetry and various atmospheric and oceanographic climatologies have been used. Several new results have been found. The small Caribbean tides have significant long-term modulations. The net effect of the low frequency modulation of the tidal signal can change the maximum tidal range up to 23.5%. The seasonal sea level cycle is characterized by large spatial and temporal variability. The amplitude of the coastal annual harmonic ranges from 2 cm to 9 cm, peaking between August and October. The amplitude of the semi-annual harmonic has maximum amplitude of 6 cm but it is not significant at all stations. The barometric effect dominates the coastal semi-annual cycle, but it is insignificant in all the other sea level frequencies at the tide-gauges. The seasonal sea level cycle from altimetry confirms the results obtained from the tide-gauges and allows the identification of some dominant sea level forcing parameters such as the Panama-Colombia gyre driven by the wind stress curl and the Caribbean Low Level Jet modulating the sea level in the northern coast of South America and linked to the local upwelling. The basin average mean sea level rise from altimetry is 1.7±1.3 mm yr-1 for the period 1993-2010. Wind forcing changes causes the trends in the southern part of the basin, modulating the sea level through changes in the ocean circulation. Significant spatial and decadal variability of the trends is found. Secular coastal sea-level trends range from 1.3±0.2 mm yr-1 in Magueyes, where the steric contribution dominates, to 5.3±0.3 mm yr-1 in Cartagena, where other contributors including local vertical land movements are significant. Temporal changes in the sea level extremes are significant but in line with mean sea-level trends at each tide gauge. With the annual mean sea level removed, extremes range between 36 cm and 79 cm, the later recorded in Port Spain and caused by the largest tidal signal. The largest nontidal residual is 76 cm found in Magueyes, forced by a hurricane induced storm surge, however larger surges can occur in the basin. The interannual sea level signal and nontidal extremes correlate with El Niño-Southern Oscillation at different time and spatial scales. No correlation with the North Atlantic Oscillation is found at any frequency. The largest sea flooding probability in the Caribbean coasts is around October, when the different sea level contributors’ maximums interact. These sea flooding events are going to became more frequent in the future due to the secular mean sea level rise affecting the basin.

Despite the large amount of research on aid effectiveness, there is still no consensus about the impact of international aid on economic growth, especially of the World Bank assistance. Empirical studies are characterised to be limited on its methodology and present diverse conclusions. Moreover, the World Bank’s contribution to economic growth in developing countries has been questioned to the point to rethink its role as a source for development. Colombia is not external to these contradictions; however, this situation arises from perception surveys and national figures. This research evaluates the impact of the World Bank’s lending on Colombia’s economic growth by estimating a model using as a reference the Solow’s model, extended to include a World Bank lending variable. It is expected a positive relationship between the World Bank disbursements and Colombia’s economic growth, which highlights the importance of updating the borrowing strategy with the World Bank in order to take the best advantage of this multilateral finance source.

This thesis considers the most current knowledge of the importance of investing in early childhood education and care (ECEC) programs with a focus on the economic benefits: higher rate of returns to education, higher productivity, lower crime rates, higher government savings and breaking up intergenerational poverty. Although the evidence suggests significant short-term effects in terms of educational benefits (e.g. lower repetition rates and special education), the empirical evidence for the economic benefits is still not as significant as it is desirable for their generalization. Therefore, it shows the need for more reliable information to construct a stronger argument leading governments to decide ipso facto increasing the educational expenditures in early childhood education programs.