School of Chemical and Metallurgical Engineering
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Item Critical evaluation of the chemical composition of acid mine drainage for the development of statistical correlations linking electrical conductivity with acid mine drainage concentrations(Elsevier, 2022-05-06) Smith, J.; Sheridan, C.; van Dyk, L.; Harding, K.G.The design an effective treatment processes for the remediation of acid mine drainage (AMD) requires an understanding of the composition of the AMD water. The pH and elemental composition of AMD waters are site specific and are dependent on the regional geology, and environmental factors. To establish the chemical and physical characteristics of two AMD sites located in the Mpumalanga coal mining region, South Africa, samples were taken between February 2018 to April 2019. These data were compared against regulatory legislation, and the potential health effects of exposure indicated. Strong correlations were noted between parameters and statistical evaluation demonstrated that electrical conductivity (EC) could be a useful correlative for prediction of total acidity, dissolved iron, and sulfur concentrations in acidic AMD waters. From these findings, empirical correlations were used to derive regression equations which were used to derive the EC values corresponding to the respective water quality limits for TDS, dissolved iron, and sulfur to provide a rapid method for testing compliance. Given the site specificity of AMD composition, this approach is intended as a proof of concept for the development of a methodology for adaption at other AMD sites. The regression equations should not be considered as universal to all AMD sites and EC should also not be used as a replacement for more complete chemical analysis.Item Critical evaluation of the chemical composition of acid mine drainage for the development of statistical correlations linking electrical conductivity with acid mine drainage concentrations(Elsevier, 2022-05-07) Smith, J.; Sheridan, C.; van Dyk, L.; Harding, K.G.Item Dealing with Under-Preparedness in Engineering Education Part 1: Defining the Goal: A Taxonomy of Engineering Competency.(American Society for Engineering Education., 2003) Woollacott, L.C.This paper emerges from work conducted on the problem of effectively addressing under-preparedness in entrants to university engineering programs in South Africa. Any educational curriculum is based on a conception of the developmental journey a learner must take in becoming a competent graduate. The conceptions underlying traditional engineering curricula do not match well with the journeys that under-prepared students with ability should take to reach their potential fully. To work towards a better match between conception and reality requires deeper understanding of the nature of under-preparedness, of engineering competency and of the determinants of engineering competency (that is, the underlying factors that determine the quality of the competencies). The first of these areas will inform the process of curriculum design by clarifying the starting point of the developmental journey. The second area will clarify the goal and the third will help to clarify what must be done to get there. This paper addresses the second of these issues –understanding engineering competency. Eight different perspectives on engineering competency have been extracted from the literature and a ninth is developed in the paper. Analysis of their similarities and differences provides a basis for developing a broader, integrated perspective that is presented as a taxonomy of engineering competency. How the taxonomy is used in acquiring a deeper understanding of competency determinants and under-preparedness will be explored in two follow up papers.Item Dealing with under-preparedness in engineering education. Part 1: Defining the goal. A taxonomy of engineering competency.(2008-07-10T11:37:22Z) Woollacott, L.C.This paper emerges from work conducted on the problem of effectively addressing under-preparedness in entrants to university engineering programs in South Africa. Any educational curriculum is based on a conception of the developmental journey a learner must take in becoming a competent graduate. The conceptions underlying traditional engineering curricula do not match well with the journeys that under-prepared students with ability should take to reach their potential fully. To work towards a better match between conception and reality requires deeper understanding of the nature of under-preparedness, of engineering competency and of the determinants of engineering competency (that is, the underlying factors that determine the quality of the competencies). The first of these areas will inform the process of curriculum design by clarifying the starting point of the developmental journey. The second area will clarify the goal and the third will help to clarify what must be done to get there. This paper addresses the second of these issues –understanding engineering competency. Eight different perspectives on engineering competency have been extracted from the literature and a ninth is developed in the paper. Analysis of their similarities and differences provides a basis for developing a broader, integrated perspective that is presented as a taxonomy of engineering competency. How the taxonomy is used in acquiring a deeper understanding of competency determinants and under-preparedness will be explored in two follow up papers.Item Eco-efficiency assessment of pork production through life-cycle assessment and product system value in South Africa(EDP Sciences, 2022-05-20) Qalase, C.; Harding, K.G.The consumption of pork as a source of animal protein has increased worldwide, especially in developing countries such as South Africa. The increase in pork demand is putting pressure on the natural environment, and the costs of production are increasing. This study sought to determine what is the eco-efficiency of pork production in a South African context. It also was meant to determine which processes in the value chain have low eco-efficiencies. Lastly, it sought to find what strategies could be recommended to improve overall eco-efficiency. Eco-efficiency was assessed by following the requirements of the International Standards Organisation ISO 14045 standard, which requires that the Life cycle assessment (LCA) method and product system value be combined. The environmental life cycle costing (LCC) method was used to determine the product system value (Value Added) of pork production. The functional unit was 1 kg of pork carcass, specifically from the cradle to the abattoir gate. The findings indicated that the pig farm and abattoir were the processes that had low eco-efficiencies and eco-efficient strategic improvements could be made. Mitigation strategies could be developed to concentrate on the production of animal feed and the use of renewable energy sources at the abattoir. The use of water could be improved by automation of the abattoir processes. Therefore, this study achieved its goal as economic and environmental areas of interest were identified in this specific case study for South Africa. This framework could be extended to study the eco-efficiency of other meat production chains and other sectors.Item Status and prospects of life-cycle assessments, carbon- and water footprinting studies in South Africa(Springer, 2021-01) Harding, K.G.; Friedrich, E.; Jordaan, H.; le Roux, B.; Notten, P.; Russo, V.; Suppen-Reynaga, N.; van der Laan, M.; Goga, T.Purpose Using the current state of life-cycle assessment (LCA), carbon-, water footprinting, and EPDs in South Africa, this work explores the challenges and opportunities for scholarly development in these areas in the country. Methods Being a relatively small LCA community in South Africa, academics, consultants, and other stakeholders were approached to provide lists of known studies, with further reports, that may have been missed, obtained through internet searches. Information was collated on database development, capacity building, and other aspects and presented here in a single paper. Results and Discussion While the authors are aware of companies working on LCA and related studies, hidden in confidential reports, we were able to find 27 LCA, 17 water-, 12 carbon footprinting, and 10 EPD studies. Although these studies have potential advantages for policymaking and business, their number, implementation, and impact remain limited. Conclusion While previously seen as an academic exercise, life-cycle thinking has been adopted by industry, private consultants, and the South African National Cleaner Production Centre (NCPC-SA), amongst others. Growing interest has led to the creation of several training courses available at academic institutes, the NCPCSA, and consulting firms, ranging from basic understanding to advanced use of software packages and modeling techniques. The development of a national LCI database, and further exposure and opportunity for LCA studies, are important steps to hopefully spur LCA in southern Africa in the future.