https://repository.biust.ac.bw/handle/123456789/411 This collection is made up of papers, posters and presentation slides presented by both FET students and staff at national, regional and international conferences, workshops and seminars. Sun, 26 Jul 2026 10:10:31 GMT 2026-07-26T10:10:31Z https://repository.biust.ac.bw/handle/123456789/749 Investigating the potential of biogas production from BIUST wastewater treatment sludge by co-digestion with slaughterhouse waste Othusitse, Nhlanhla; Dlamini, Gcinumuzi; Jonas, Mbako; Mamvura, Tirivaviri; Agachi, Paul S. Wastewater treatment is a necessity in any community and civilization particularly where water is a scarce natural resource. The Botswana International University of Science and Technology is habitat to a community of just under 5000 people and has its own dedicated wastewater treatment plant. Currently this plant is managed by the university and boasts of 7 ponds. The plant follows a conventional four stage process; starting off with screening and grit removal, then removal of suspended solids through sedimentation, breakdown of organic matter through biological processes, then lastly filtration, disinfection, and use of chemical treatment to ensure compliance with quality standards before final discharge. This research aims at the third stage of biological processing to explore potential for biogas production potential from BIUST wastewater treatment sludge (WTS). Presently the anaerobic digestion ponds are open to the atmosphere and therefore release methane to the atmosphere adding to greenhouse gas emissions. To investigate, four different ratios of sludge (SL) to slaughterhouse waste (SHW) (1:1, 1:3, 3:1, 2:3) were co-digested, and the two substrates mono digested. The experiment was conducted over a retention time of 32 days in 2L reactor vessels. The results for bio-methane potential revealed that sludge: slaughterhouse waste 1:3 accumulated the highest volume of biogas (10,446.4 NmL CH4/gVS), sludge on its own accumulated the lowest volume of biogas (3,134.9 NmL CH4/gVS). The ratio of 2:3 exhibited the most optimal physiochemical properties for biogas production, promising a high turnover of gas produced. The premeditated assumption was later discovered to be false, as the volume accumulated was relatively low (3435.8 NmL CH4/ gVS) only increasing by 9.6% compared to the lone digestion of sludge. Ratio of 3:1 yielded a biogas of 5,686.1 NmL CH4/gVS, showing an 81% increase in biogas yield compared to mono-digestion of sludge. Therefore, co-digestion of sludge with slaughterhouse waste at a 3:1 ratio shows great potential for biogas production from BIUST waste treatment sludge. Mon, 22 Jul 2024 00:00:00 GMT https://repository.biust.ac.bw/handle/123456789/749 2024-07-22T00:00:00Z https://repository.biust.ac.bw/handle/123456789/748 Hybrid machine learning and genetic algorithms for environmental impact and energy management to enhance mining sustainability Parvathareddy, Sravani; Yahya, Abid; Amuhaya, Lilian Livutse; Ravi, Samikannu The mining industry confronts the challenge of balancing economic prosperity and environmental sustainability. This research presents a comprehensive approach that leverages big data analytics and machine learning techniques to address this challenge. Unlike traditional approaches that focus on mitigating impacts post-occurrence, our method advocates for proactive measures throughout operational phases. We introduce a cohesive system integrating advanced technologies to analyze vast datasets, including real-time environmental sensor data, satellite imagery, company reports, and government records. The framework encompasses data pre-processing, model building, analysis, and recommendations. To predict environmental outcomes and assess sustainability, we employ a genetic algorithm (GA) and machine learning tools such as XGBoost, support vector regressor (SVR), and K-nearest neighbors (KNN) regressor algorithms. Data pre-processing ensures data accuracy and consistency. We use clustering and recommendation algorithms for analysis and suggestions, identify improvement areas, and propose environmental management solutions. This methodology underscores the importance of empowering stakeholders to anticipate environmental consequences, mitigate potential hazards, and continuously improve sustainability initiatives through real-time insights. By integrating big data analytics and machine learning, we enhance the environmental sustainability of mining operations, fostering a harmonious balance between environmental stewardship and economic returns. The benefits of our system are manifold, including improved environmental management, reduced environmental risks, and enhanced sustainability practices in the mining industry, thereby highlighting the crucial role of stakeholders in this process. Mon, 22 Jul 2024 00:00:00 GMT https://repository.biust.ac.bw/handle/123456789/748 2024-07-22T00:00:00Z https://repository.biust.ac.bw/handle/123456789/507 Software controlled stepping valve system for a modern car engine Zibani, I; Marumo, R; Chuma, Joseph; Ngebani, I To address the problem of a piston-valve collision associated with poppet valve engines, we replaced the conventional poppet valve with a solenoid operated stepping valve whose motion is perpendicular to that of the piston. The valve events are software controlled, giving rise to precise intake/exhaust cycles and improved engine efficiency. Other rotary engine models like the Coates engine suffer from sealing problems and possible valve seizure resulting from excessive frictional forces between valve and seat. The proposed valve on the other hand, is located within the combustion chamber so that the cylinder pressure help seal the valve. To minimize friction, the valve clears its seat before stepping into its next position. The proposed system was successfully simulated using ALTERA's QUARTUS II Development System. A successful prototype was built using a single piston engine. This is an ongoing project to eventually produce a 4-cylinder engine. Sun, 01 Oct 2017 00:00:00 GMT https://repository.biust.ac.bw/handle/123456789/507 2017-10-01T00:00:00Z https://repository.biust.ac.bw/handle/123456789/506 Chemical absorption of carbon dioxide in Biogas Purification Maile, O.M.; Muzenda, E.; Tesfagiorgis, H. Biogas is produced from anaerobic digestion of organic biodegradable materials. However, its application is limited as it contains impurities such as carbon dioxide (CO2), hydrogen sulphide (H2S), and other trace gases. Chemical absorption is capable of producing gas of high methane content above 95% and has no methane losses hence it's widely used on large scale applications. Sodium hydroxide was used for cleaning the biogas in this study at a concentration of 1 M, 2 M, and 3 M. The effect of concentration on absorption and CO2 removal efficiency was studied. It was observed that an increase in concentration lead to an increase in the absorption rate and the removal efficiency respectively. The highest removal efficiency was recorded to be 66%. Sun, 01 Jan 2017 00:00:00 GMT https://repository.biust.ac.bw/handle/123456789/506 2017-01-01T00:00:00Z