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Item Evaluation of rock stability challenges affecting the formation of sustainable pit lake towards mine closure following crown pillar extraction in open pit-underground mines(Elsevier BV, 2024) Massawe,Victor A.; Bahtiyar UnverThe extraction of high-grade ore from the crown pillar (CP) in open pit-underground mines poses stability challenges and potential environmental risks. While an open pit has the potential to transition into a pit lake, the extraction of CP can induce failure in the surrounding walls, preventing the formation of the lake. There is also a concern that the backfilling material may not effectively confine toxic water within the pit, thereby risking contamination of the underground environment. To address these issues, a case study was conducted using FLAC3D and 3DEC models to evaluate the extent of failure caused by CP extraction. On-site observation, along with modelling, has revealed rock damage, including deformation stretching about 4 m from the pit wall and extending vertically from the pit floor to the ramp. The study identified three primary factors leading to pit wall failure or damage: steep pit slopes reaching approximately 70° near the pit floor, an underestimated CP thickness by about 4 m, and the concurrent extraction of ore from the pit wall alongside CP. Based on these findings, rehabilitation measures are suggested, including excavation of the deformed wall and cantilever, as well as partial pit backfilling. There is a substantial increase in the volume of backfill material as the extent of failure increases, which raise concerns about the decision-making process regarding CP extraction. Therefore, this article aims to raise environmental awareness and evaluate whether the benefits of ore extraction outweigh the considerations for pit wall support and the rehabilitation efforts during mine closure.Item Optimizing ciprofloxacin removal from water using jamun seed (Syzygium cumini) biochar: A sustainable approach for ecological protection(Elsevier BV, 2024) Asha Ripanda; Mwemezi J. Rwiza; Elias Charles Nyanza; Linda Numph Bih; Miraji Hossein; Ramadhani Bakari; Somit Kumar Sigh; Giridhar Reddy; C.R. Ravikumar; H.C. Ananda Murthy; Karoli N. Njau; Said Ali Hamad Vuai; Revocatus L. MachundaScientific interest in antimicrobial pollutants, such as ciprofloxacin, has increased. Due to spread of antibioticresistant bacteria, resistance genes, and their dissemination to the environment. Therefore, their remediation is necessary to ensure ecological sustainability. The current study aimed to optimise the removal of ciprofloxacin from synthetic water using jamun seed (JS) (Syzygium cumini) biochar using a response surface methodology (RSM). Result indicates ciprofloxacin elimination efficiency ranged between 32.46 and 94.95%, indicating the material can be improved and used for remediation of organics. The residual standard error of 4.4% were found for the predicted model, implying that the model is credible and can be used to predict future experimental findings. The R-squarred value for the improved Langmuir model's R2 is 0.9681 which is inclose agreement with the Freundlich isotherm, R2 0.9757. Therefore, JS biochar could be utilized for the remediation of ciprofloxacin from contaminated water and wastewater for ecological safety and sustainability.Item Biofuel and biorefinery technologies volume 8: biodiesel: from production to combustion(Tylor & Francis, 2022) Kombe, Godlisten GladstoneGlobal environmental concerns about reducing greenhouse gas emissions and relying less on nonrenewable oil fuels have paved the way for biodiesel and other renewable energy sources. Unfortunately, despite increased demand for biodiesel fuel, the industry's growth has been hampered by low worldwide petrol-diesel prices. To solve this conundrum, the authors provided a thorough discussion of various policies that promote biodiesel development, cutting-edge prospective production technologies, life cycle assessment, and techno-economic analysis of biodiesel plants. This review attempts to analyze various issues as presented in this book. The book contains cutting-edge biodiesel manufacturing, purification, and upgrading techniques. It investigates global biodiesel production and its possible role in reducing the consequences of climate change. Biodiesel by-product uses, biodiesel plant techno-economic issues, and biodiesel life cycle assessment (LCA), among other issues, have all been comprehensively explored.