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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Best management practices to attain zero effluent discharge in South African industries / C.G.F. Wilson

Wilson, Christiaan Georg Frederick January 2008 (has links)
Wastewater treatment is traditionally considered a separate part of an industrial activity, hardly connected to the production units themselves. It is nowadays essential to ensure that the quality of water is not degraded and that water that has been polluted is purified to acceptable levels, especially in a country with scarce water resources such as South Africa. Where water quality is concerned, Zero Effluent Discharge (ZED) is the ultimate goal, in order to avoid any releases of contaminants to the water environment. The push towards ZED in South Africa is also promoted further by the South African Government’s plan to reduce freshwater usage and the pollution of water sources due to the water scarcity in a semi-arid South Africa. Future legislation will see a marked increase in the cost of freshwater usage and/or a possible limitation of the quantity of freshwater available. There is a need in the South African Industry for a framework of Best Management Practices (BMPs) in order to provide interested stakeholders, which include not only industry, but also academia, environmental interest groups and members of the public, with a procedure to meet the ZED statutory requirements. This dissertation explores the regulatory requirements and current environmental management practices implemented. A framework of BMPs to successfully attain ZED status in South African industries is developed from the literature study and the researcher’s own experience. The BMP framework embodies practices for one integrated strategy within three dimensions. The three dimensions of the BMP framework were selected to differentiate between BMPs for management (Governance BMPs), the project management team responsible for ZED projects (Project Management BMPs) and the implementation of preventative and operational measures to obtain and sustain ZED compliance for South African industries. The BMP framework was validated against the practices applied by Mittal Steel. The Mittal Steel plant in Vanderbijlpark implemented various projects, reduced the intake of water and eliminated the discharge of effluent and by doing this successfully realised their ZED status. The BMP framework will enable South African industries to develop their own BMPs Manual which should be specific to their operational and environmental requirements. The implementation of these BMPs should be tailored and used accordingly to demonstrate compliance to ZED requirements in South African industries. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2009.
12

Synthesis and characterization of pine cone carbon supported iron oxide catalyst for dye and phenol degradation

Mmelesi, Olga Kelebogile 06 1900 (has links)
M. Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology / Fenton oxidation is classified into two processes, homogeneous and heterogeneous. Homogeneous Fenton oxidation process, have been shown to be efficient in the degradation of organic pollutants. However, it was shown to have limitations which can be addressed by the heterogeneous Fenton oxidation. Despite the high efficiency of the heterogeneous Fenton oxidation process in the degradation of recalcitrant organic pollutants, the currents synthesis trends of the heterogeneous Fenton catalyst have been proven to be time and energy constraining, since it involves the multi-step were the activated carbon have to be prepared first then co-precipitate the iron oxide on the activated carbon. However, as much as the heterogeneous Fenton catalyst has been proven to have high catalytic activity towards degradation of organic pollutants, these catalysts have some limitations, such limitations include metal ions being leached from the catalyst support into the treated water causing catalyst deactivation and a secondary pollution to the treated water. In this thesis, these catalysts have been applied in the degradation of recalcitrant organic pollutants such as methylene blue and phenols. This study focuses on the single step synthesis of iron oxide nanoparticles supported on activated carbon, were carbonaceous material is impregnated with iron salt then pyrolysed via microwave heating. Microwave power and the amount of iron salt were optimized. The prepared activated carbon-iron oxide composites were applied to the degradation of 2-nitrophenol (2-NP) and methylene blue (MB). Methylene blue was used as a model compound due to the fact that it is easier to monitor the degradation process with UV-Vis as compared to 2-nitrophenol . 2-nitrophenol the additional step for the adjustment of pH is required since nitrophenols are colorless in color at lower pH. The characterization showed that the microwave power and the amount of the iron precursor have an influence on the porosity and surface functional groups of the activated carbon. Further it was vi observed that microwave power and iron precursor influnces the amount of iron oxide formed on the surface of the support. It was also observed that the activated carbon-iron oxide composite have the catalytic effects on the Fenton oxidation process of MB and 2-NP. The parameters such as H2O2, pH, catalyst dose, initial concentration, temperature affect the degradation of both MB and 2-NP. Kinetics studies showed that Fenton is a surface driven reaction since the results fitted the pseudo first order model. The thermodynamics parameters also showed that the reaction is endothermic, spontaneous and is randomized. This implies that the reaction of the degradation of MB and 2-NP is feasible and the catalysts prepared have high catalytic activity. MB and 2-NP were degraded to smaller organic molecules (carboxylic acids). The stability of the catalyst observed to decrease as the number of cycles increased, this is due to the leaching of iron ions from the support material. Hence it was concluded that the activated carbon-iron oxide composite was successfully synthesized and had the high catalytic activity for the degradation of MB and 2-NP.

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