[pt] No Brasil está em larga expansão o uso de geração de eletricidade por termoeléctricas. Na geração de eletricidade por usinas térmicas são utilizados grandes quantidades de água e produtos químicos, que após utilização geram efluentes. A hidrazina é um produto químico usado para controle de corrosão em águas de caldeiras, sistemas de vapor e outros sistemas de usinas térmicas que após utilização acaba incorporada aos efluentes líquidos destas usinas. Com intuito de promover uma sistemática de controle de efluentes produzidos nas usinas, procurou-se, nesta dissertação, estudar efluentes contendo hidrazina com enfoque tecnológico. O processo abordado neste estudo consistiu no tratamento de efluentes contendo hidrazina, utilizando peróxido de hidrogênio com auxílio de catalisador de íons de cobre, para decomposição da hidrazina. Os ensaios foram feitos em laboratório, utilizando-se efluentes sintéticos com concentrações pré- determinadas de hidrazina que variaram entre 10 e 100 mg/L, com controle do pH que variou em 7 e 9,5, temperatura fixada em 220C, com adição de concentrações calculadas de peróxido de hidrogênio e catalisador de sulfato de cobre. Concluiu-se que o processo é viável para reduzir a concentração de hidrazina em efluentes a níveis inferiores aos limites da legislação (1 mg/L), utilizando-se quantidades estequiométricas de peróxido de hidrogênio em conjunto com sulfato de cobre em concentrações de 1 mg/L de Cu 2+ como catalisador, em efluentes com pH 9,5, a temperatura ambiente, em tempos inferiores a 30 minutos. Assim sendo, o trabalho mostrou-se adequado para satisfazer as condições de descarte de efluentes em águas brasileiras de acordo com a resolução CONAMA 20, carta P-031/01 cláusula 2 artigo V, de 9 de Fevereiro de 2001. / [en] In Brazil, the use of energy produced by power plant generators is in expansion. Power plants use large quantities of water and chemical products that after use end up in effluents. Hydrazine is used in water systems for corrosion control, because of its excelents oxygen scavenging capacity. The present work was conducted to study the treatment of effluents containing hydrazine, under a technological approach, with the purpose of contributing to a systematic of effluents control in power stations. The process studied in this work was the decomposition of hydrazine with hydrogen peroxid in presence catalyst cooper íon. The experiments were made in laboratory scale, using synthetic effluents with initial concentration of hydrazine at the levels 10 and 100 mg/L, with initial pH values 7 and 9,5, temperature fixed at 220C, with addition of st oichiometric amounts of hydrogen peroxide, with and without addition of cooper ion catalyst. It was conclued that the process its viable for reduction of hydrazine concentration in effluents with pH 9,5, below to levels under legislation (1mg/L), using stoichiometric amounts of hydrogen peroxide together with 1 mg/L of cooper ion, in times less that 30 minutes and ambient temperature. Therefore this work showed that the process is adequate in satisfying the Brazilian legislation for discharge of effluents into water bodies according to regulation CONAMA 20, letter P-031/01 clause 2 article V, 09 February 2001.

Public participation can be defined as ...”a process leading to a joint effort by stakeholders, technical specialists, the authorities and the proponent who work together to produce better decisions than if they had acted independently" (Greyling, 1999, p. 20). In South Africa, public participation processes are legally driven and form part a statutory part of environmental impact assessments. Many environmental impact assessments have been undertaken in South Africa, but the environmental impact assessment undertaken for the proposed construction of a demonstration module pebble bed modular reactor was perhaps one of the biggest studies undertaken to date from a public participation process point of view (Smit, 2003). The main aim of this mini-dissertation was to evaluate the public participation process followed for the environmental impact assessment of the demonstration module pebble bed modular reactor at Koeberg in the Western Cape Province against the criteria for fairness and competence as set out by Webler (In: Renn et al., 1995). Despite the fact that this work is eleven years old, it is still regarded as a benchmark for the evaluation of public participation processes in environmental decision making (Abelson et al., 2003). Webler (In: Renn et al., 1995) developed a normative theory for fairness and competence in public participation based on the theory of ideal speech of German sociologist Jürgen Habermas. Habermas’ main contribution to science was his theory of universal pragmatics (Author unknown, 2005). Universal pragmatics is a theory aimed at explaining how language is used to ensure mutual understanding and agreement. Webler (In: Renn et al., 1995) argues that the conditions of universal pragmatics, if applied to public participation, points towards the concepts of fairness (providing everyone with the opportunity to participate) and competence [providing participants (called interested and affected parties (I&APs) with the opportunity to make, question and validate speech acts]. Habermas advocates that each statement (or speech act) makes at least one validity claim and that there is a presupposition that the speaker can validate each claim to the satisfaction of all communication partners, should this be necessary (Perold, 2006). Furthermore, Habermas identifies four different types of validity claims, each having to do with a specific type of statement. In his theory, communicative speech acts have to do with comprehensibility; constantive speech acts with truth/correctness; regulative speech acts with normative rightness and representative speech acts with sincerity. Webler (In: Renn et al., 1995) developed a set of criteria to evaluate the fairness and competence in public participation. This set of criteria was applied to the public participation process of the case study. The study found that the process followed in the case study did not fare particularly well in either fairness or competence, but that fairness was slightly better than competence. The most alarming finding was that little attempt was made to ensure that validity claims – especially constantive (truth and factual information) – were validated or redeemed as this left the door open for misinterpretation, politics and incorrectness. It was also found that I&APs were, for the most, prevented from participating in the decision-making process. This finding may or may not be interpreted as negative as the public participation consultant never made a claim towards power sharing as well as the fact that there are widely differing opinions regarding the level to which public participation should take place. It was suggested that at least some elements of power sharing be incorporated into future processes, that validity claims – especially constantive (theoretical/factual) and therapeutic (regarding feelings and emotions) – must be able to stand up to scrutiny and should be validated. Finally, it was suggested that more attention be given to representative speech acts (statements regarding emotions, perceptions and feelings). / Dr. J. M. Meeuwis

The topic of this work is the renewal of hermetic pipe penetrations within the primary loop of a nuclear power station. A description of the Dukovany nuclear power plant is included at the beginning, ranging from basic description to details of the renewed component and the reasoning for its replacement. Following is a description of the technologies, which are applied in order to restore the hermetic pipes, the choice of the placement of the heterogeneous weld and the compilation of a workflow for the renewal in the environment of the primary loop while maintaining the quality standards and the strict safety conditions. The conclusion includes a calculation of the expenses tied with the chosen variant the reasoning behind the renewal regarding the length of the outage.

The master’s thesis follows up the possibility of using renewable for making electric power. It detects conditions of further development in this discipline and external factors which are applied to business. It rates from economic view little hydroelectric, wind and photovoltaic power stations. In business plan it elaborates in detail prosecution of the little hydroelectric plants, which is at the end subjected to financial analysis and it’s decided if this business makes sense.

The purpose of this dissertation is to discuss the engineering design of the supporting structure for solar photovoltaic panels with a total area of 200 metres square. The supporting structure is intended for implementation as part of a solar power station. The preamble of the dissertation examines photovoltaic power stations, their types, advantages and disadvantages. The focus of the second part is directed toward the project of constructing the supporting structure and it also deals with the tasks of attaching the photovoltaic panels and putting the panel’s supporting structure in place. This section will also propose methods of continuously monitoring both the panel and its support-structure once they have been constructed and brought into operation. The purpose of part three is to perform the calculations concerning the entire structure’s required load-bearing properties through the use of the Final Element Method in the program “ANSYS 11.0”. The conclusion of this dissertation is devoted to the evaluation and economic analysis of the construction.

The thesis addresses the proximity of contemporary global human issues to local human issues and presents an architectural solution. By identifying, exploring and drawing closer the proximities between these global and local issues, new solutions can be developed for local application. There are new fields created for architecture when we understand and connect the proximity of objects of both cultural and biophysical creation, and when we understand and build on our ever-narrowing proximities between what has been and what is to come. The narrowing global conditions have direct implications on us as individual human beings and our individual local societies. These proximities have been explored, developed, and resolved for local application. The resulting research field for urban agriculture ultimately guided an appropriate architectural response within the city of Pretoria, South Africa. / Dissertation (MArch(Prof))--University of Pretoria, 2010. / Architecture / unrestricted

Sustainable development is described by the World Commission on Environment and Development as ―development that meets the needs of present without compromising the ability of future generations to meet their own needs‖. Sustainability assessments are an integrative process and framework for effective integration of social, economic and ecological considerations in significant decision-making processes. Sustainability is incorporated into South African legislation such as the Constitution of the Republic of South Africa (1996), the National Environmental Management Act (Act 107 of 1998), as well as Environmental Impact Assessment (EIA) Regulations. Despite the existence of such legislation, the challenge lies in the effective implementation of the EIA process, which has been identified as a useful tool in striving towards achieving sustainable development. This research uses Gibson‘s eight sustainability principles and Gaudreau and Gibson‘s sub-criteria to develop a case specific set of sustainability criteria for coal fired power stations in South Africa. The energy generation sector is a major source of social and environmental impacts. Coal power stations contribute to environmental degradation such as reduced air, water and land quality. This industrial process impacts on the environment and therefore needs to strive towards sustainable development by considering these criteria during the EIA process. The set of case specific sustainability criteria for power stations was then used to evaluate the EIA developed for Medupi Power Station in South Africa in order to assess, the extent to which sustainability was considered in the EIA process. The key finding is that sustainability is incorporated into South African legislation hence no change in legislation is required. Despite the existence of legislation, the challenge lies in the fact that is it not always effectively implemented. The EIA process is seen as a tool that can effectively deliver sustainability outcomes. However this process is not effectively utilised. In order for the EIA to consider sustainability the focus needs to be on the following criteria: Intragenerational Equity; Precaution and Adaptation for Resilience; as well as Immediate and Long term Integration, as these were recognised as weaknesses after the evaluation process. The recommendation is also to develop a set of case specific sustainability criteria for other large industries that have significant environmental impacts. / MSc (Environmental Management), North-West University, Potchefstroom Campus, 2015

Conventional concentrating solar power (CSP) plants typically have a very high levelised cost of electricity (LCOE) compared with coal-fired power stations. To generate 1 kWh of electrical energy from a conventional linear Fresnel CSP plant without a storage application, costs the utility approximately R3,08 (Salvatore, 2014), whereas it costs R0,711 to generate the same amount of energy by means of a highly efficient supercritical coal-fired power station, taking carbon tax into consideration. This high LCOE associated with linear Fresnel CSP technology is primarily due to the massive capital investment required per kW installed to construct such a plant along with the relatively low-capacity factors, because of the uncontrollable solar irradiation. It is expected that the LCOE of a hybrid plant in which a concentrating solar thermal (CST) station is integrated with a large-scale supercritical coal-fired power station, will be higher than that of a conventional supercritical coal-fired power station, but much less than that of a conventional CSP plant. The main aim of this study is to calculate and then compare the LCOE of a conventional supercritical coal-fired power station with that of such a station integrated with a linear Fresnel CST field. When the thermal energy generated in the receiver of a CST plant is converted into electrical energy by using the highly efficient regenerative Rankine cycle of a large-scale coal-fired power station, the total capital cost of the solar side of the integrated system will be reduced significantly, compared with the two stations operating independently of one another for common steam turbines, electrical generators and transformers, and transmission lines will be utilised for the integrated plants. The results obtained from the thermodynamic models indicate that if an additional heat exchanger integration option for a 90 MW (peak thermal) fuel-saver solar-augmentation scenario, where an annual average direct normal irradiation limit of 2 141 kWh/m2 is considered, one can expect to produce approximately 4,6 GWh more electricity to the national grid annually than with a normal coal-fired station. This increase in net electricity output is mainly due to the compounded lowered auxiliary power consumption during high solar-irradiation conditions. It is also found that the total annual thermal energy input required from burning pulverised coal is reduced by 110,5 GWh, when approximately 176,5 GWh of solar energy is injected into the coal-fired power station’s regenerative Rankine cycle for the duration of a year. Of the total thermal energy supplied by the solar field, approximately 54,6 GWh is eventually converted into electrical energy. Approximately 22 kT less coal will be required, which will result in 38,7 kT less CO2 emissions and about 7,6 kT less ash production. This electricity generated from the thermal energy supplied by the solar field will produce approximately R8,188m in additional revenue annually from the trade of renewable energy certificates, while the reduced coal consumption will result in an annual fuel saving of about R6,189m. By emitting less CO2 into the atmosphere, the annual carbon tax bill will be reduced by R1,856m, and by supplying additional energy to the national grid, an additional income of approximately R3,037m will be due to the power station. The annual operating and maintenance cost increase resulting from the additional 171 000 m2 solar field, will be in the region of R9,71m. The cost of generating 1 kWh with the solar-augmented coal-fired power plant will only be 0,34 cents more expensive at R0,714/kWh than it would be to generate the same energy with a normal supercritical coal-fired power station. If one considers that a typical conventional linear Fresnel CSP plant (without storage) has an LCOE of R3,08, the conclusion can be drawn that it is much more attractive to generate electricity from thermal power supplied by a solar field, by utilising the highly efficient large-scale components of a supercritical coal-fired power station, rather than to generate electricity from a conventional linear Fresnel CSP plant. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Sustainable development is described by the World Commission on Environment and Development as ―development that meets the needs of present without compromising the ability of future generations to meet their own needs‖. Sustainability assessments are an integrative process and framework for effective integration of social, economic and ecological considerations in significant decision-making processes. Sustainability is incorporated into South African legislation such as the Constitution of the Republic of South Africa (1996), the National Environmental Management Act (Act 107 of 1998), as well as Environmental Impact Assessment (EIA) Regulations. Despite the existence of such legislation, the challenge lies in the effective implementation of the EIA process, which has been identified as a useful tool in striving towards achieving sustainable development. This research uses Gibson‘s eight sustainability principles and Gaudreau and Gibson‘s sub-criteria to develop a case specific set of sustainability criteria for coal fired power stations in South Africa. The energy generation sector is a major source of social and environmental impacts. Coal power stations contribute to environmental degradation such as reduced air, water and land quality. This industrial process impacts on the environment and therefore needs to strive towards sustainable development by considering these criteria during the EIA process. The set of case specific sustainability criteria for power stations was then used to evaluate the EIA developed for Medupi Power Station in South Africa in order to assess, the extent to which sustainability was considered in the EIA process. The key finding is that sustainability is incorporated into South African legislation hence no change in legislation is required. Despite the existence of legislation, the challenge lies in the fact that is it not always effectively implemented. The EIA process is seen as a tool that can effectively deliver sustainability outcomes. However this process is not effectively utilised. In order for the EIA to consider sustainability the focus needs to be on the following criteria: Intragenerational Equity; Precaution and Adaptation for Resilience; as well as Immediate and Long term Integration, as these were recognised as weaknesses after the evaluation process. The recommendation is also to develop a set of case specific sustainability criteria for other large industries that have significant environmental impacts. / MSc (Environmental Management), North-West University, Potchefstroom Campus, 2015

Conventional concentrating solar power (CSP) plants typically have a very high levelised cost of electricity (LCOE) compared with coal-fired power stations. To generate 1 kWh of electrical energy from a conventional linear Fresnel CSP plant without a storage application, costs the utility approximately R3,08 (Salvatore, 2014), whereas it costs R0,711 to generate the same amount of energy by means of a highly efficient supercritical coal-fired power station, taking carbon tax into consideration. This high LCOE associated with linear Fresnel CSP technology is primarily due to the massive capital investment required per kW installed to construct such a plant along with the relatively low-capacity factors, because of the uncontrollable solar irradiation. It is expected that the LCOE of a hybrid plant in which a concentrating solar thermal (CST) station is integrated with a large-scale supercritical coal-fired power station, will be higher than that of a conventional supercritical coal-fired power station, but much less than that of a conventional CSP plant. The main aim of this study is to calculate and then compare the LCOE of a conventional supercritical coal-fired power station with that of such a station integrated with a linear Fresnel CST field. When the thermal energy generated in the receiver of a CST plant is converted into electrical energy by using the highly efficient regenerative Rankine cycle of a large-scale coal-fired power station, the total capital cost of the solar side of the integrated system will be reduced significantly, compared with the two stations operating independently of one another for common steam turbines, electrical generators and transformers, and transmission lines will be utilised for the integrated plants. The results obtained from the thermodynamic models indicate that if an additional heat exchanger integration option for a 90 MW (peak thermal) fuel-saver solar-augmentation scenario, where an annual average direct normal irradiation limit of 2 141 kWh/m2 is considered, one can expect to produce approximately 4,6 GWh more electricity to the national grid annually than with a normal coal-fired station. This increase in net electricity output is mainly due to the compounded lowered auxiliary power consumption during high solar-irradiation conditions. It is also found that the total annual thermal energy input required from burning pulverised coal is reduced by 110,5 GWh, when approximately 176,5 GWh of solar energy is injected into the coal-fired power station’s regenerative Rankine cycle for the duration of a year. Of the total thermal energy supplied by the solar field, approximately 54,6 GWh is eventually converted into electrical energy. Approximately 22 kT less coal will be required, which will result in 38,7 kT less CO2 emissions and about 7,6 kT less ash production. This electricity generated from the thermal energy supplied by the solar field will produce approximately R8,188m in additional revenue annually from the trade of renewable energy certificates, while the reduced coal consumption will result in an annual fuel saving of about R6,189m. By emitting less CO2 into the atmosphere, the annual carbon tax bill will be reduced by R1,856m, and by supplying additional energy to the national grid, an additional income of approximately R3,037m will be due to the power station. The annual operating and maintenance cost increase resulting from the additional 171 000 m2 solar field, will be in the region of R9,71m. The cost of generating 1 kWh with the solar-augmented coal-fired power plant will only be 0,34 cents more expensive at R0,714/kWh than it would be to generate the same energy with a normal supercritical coal-fired power station. If one considers that a typical conventional linear Fresnel CSP plant (without storage) has an LCOE of R3,08, the conclusion can be drawn that it is much more attractive to generate electricity from thermal power supplied by a solar field, by utilising the highly efficient large-scale components of a supercritical coal-fired power station, rather than to generate electricity from a conventional linear Fresnel CSP plant. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015