http://ir.bdu.edu.et/handle/123456789/10131 2001-01-13T05:52:00Z http://ir.bdu.edu.et/handle/123456789/15971 Environmental assessment of used lubricant oil management methods: case study in Bahir Dar city, Ethiopia Beakal, Tadesse Adane The proper management of used lubricant oil is crucial for reducing the negative impact on the environment. This study evaluates the current used lubricant oil management practices in Bahir Dar, Ethiopia, and aims to identify potential environmental impacts associated with these practices. Through a review of literature, field research, and interviews with stakeholders and experts in the field, this study characterizes the used lubricant oils in Bahir Dar City and compares them to the properties of used lubricant oils from other countries. Qualitative and quantitative research methods were employed to gain an in-depth understanding of present practices and attitudes towards used lubricant oil in Bahir Dar. The survey results suggest troubling trends in the awareness and behaviors surrounding the handling and disposal of spent oil. This study focuses on analyzing the samples of used lubricating oils in Bahir Dar, Ethiopia, to better understand the composition and metal concentration of the city's waste oil. The data show that the used lubricating oil in Bahir Dar has a complicated composition with varied amounts of components and additives. The analysis found high quantities of metals including copper and lead in the oil, indicating serious corrosion and wear. Metal concentrations in used oil samples surpass allowed levels, posing a risk to the environment and human health. The report also estimates the annual production of used oil in Bahir Dar, emphasizing the importance of appropriate waste oil treatment procedures to reduce severe environmental consequences. Heavy metals with diverse ecological potentials include zinc, copper, lead, chromium, and cadmium. Inadequate disposal can have negative consequences for human health and the ecosystem, including bioaccumulation in the food chain. Acid rain potential (ARP) and ecotoxicity potential (ETP) are critical considerations. The potential contribution of phosphorus and nitrogen to eutrophication, which results in hazardous algal blooms and oxygen depletion in aquatic habitats, is referred to as eutrophication potential (EP). The study also considers energy consumption, environmental impact, and cost-effectiveness. Hydro-treating, distillation, and acid-clay treatment are suitable for removing pollutants and impurities. This current used oil management practices in the city pose significant environmental risks and requires the implementation of improved management practices that promote environmental sustainability. The research provides information decision-making on used lubricant oil management in Bahir Dar. The results of this research contribute to the development of improved management practices in the city, ultimately mitigating its negative environmental impact. 2024-03-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/15970 Molybdenum/Iron based single/dimer atomic electro-catalysts for value-added water electrolysis, electrochemical CO2 reduction and oxygen reduction reaction applications Tesfaye, Alamirew Dessie 2024-03-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/15969 Extraction and optimization of animal glue from untanned pickled leather wastes and quality enhancement using Carboxyl Methyl Cellulose (CMC) Seblewongel, Desta Untanned Pickled skin waste is a solid byproduct obtained before the tanning process and is characterized by its high protein and acid content. Despite its richness in protein compounds, this particular waste stream within the tannery industry remains underutilized. Animal glue, derived from the extended boiling of animal connective tissue waste obtained from the tannery industry, serves as a specific type of adhesive. The objective of this study was to extract animal glue from untanned pickled leather waste and enhance its physico-chemical and mechanical properties by incorporating a renewable carboxyl methylcellulose (CMC) additive. Raw materials obtained from the Bahir Dar Tannery were subjected to washing with tap water and pretreatment, involving soaking in water and diluted sulfuric acid to facilitate the partial hydrolysis of collagen peptide. The extraction process was carried out in a water bath, with a soaking concentration ranging between 0% and 1%, a boiling temperature between 60 OC and 80 OC, and a boiling time of 2 to 4 hours. The resulting solution was filtered, and the collagenous material retained on the filter was subsequently dried. After the drying process, the glue was cooled and subjected to characterization. The optimal conditions for extraction were found to be a soaking reagent concentration of 1%, a temperature of 70 °C, and a time of 3 hours, yielding the best results and quality indicators. These indicators included a shear strength of 81.64 MPa, a viscosity of 81 cp, a moisture content of 15.19%, an ash content of 2.08%, a pH of 5.7, and a yield of 49.90 g of glue per 100 g of pickled skin. Furthermore, when the CMC additive (0.4%) was incorporated, improvements were obtained in quality parameters such as viscosity, shear strength, and moisture content, resulting in values of 88.1 cp, 97 MPa, and 15.23%, respectively. This enhancement further improved the durability of the extracted glue. Additionally, the results indicated that both the extracted glue and the enhanced glue exhibited quality parameters comparable to those of commercial glue, which are standard values for shear strength (12 to 13 MPa), viscosity (80 to 90 cp), moisture content (8 to 16%), and ash content (2 to 4.5%). Key words: Pickled leather waste, Improved animal glue, sustainability 2024-02-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/15968 Combined Photo-Fenton and Electrocoagulation Process for Removal of Pharmaceuticals from Wastewater Hamelmal, Ewunetu The wastewater produced in many different operations in the pharmaceutical industry are considered as an environmental problem because of their hazardous and potential impacts on the aquatic ecosystem and human. Among various pharmaceuticals, antibiotics attract significant attention in wastewater due to their eco-toxicological effects and the potential for the development of antibiotic-resistant bacteria. This thesis focuses on the selection of amoxicillin from the penicillin group, and existing studies indicate that single treatment strategies are often ineffective in removing this pharmaceutical. In this study, the removal of amoxicillin from wastewater by combination of electrocoagulation and photo-Fenton processes was investigated. Response Surface Methodology (RSM) was used to assess the impact of key parameters and optimize all influencing factors through Box–Behnken design. For the optimization of the initial experimental conditions, drug degradation and chemical oxygen demand (COD) removal are measured as the objective parameters. All parameters determined using the methodology established in the standard method for the examination of water and wastewater. Under optimized conditions of Photo-Fenton process complete degradation (99%) and 80% COD removal were achieved at an initial amoxicillin concentration of 65 mg/L, Fe2+ concentration of 33 mg/L, H2O2 concentration of 219 mg/L, pH of 3.0 and reaction time of 60 min. In addition, in electrocoagulation process maximum amoxicillin removal 87% were found at pH 7.5, current density of 0.9A and reaction time of 38 min. The performance of combined processes was investigated by using optimum conditions of individual processes and exhibited an impressive AMO degradation efficiency of 100% and COD removal efficiency of 95%. In real wastewater also reached 98% amoxicillin removal and 88% COD removal at optimum conditions. This efficient degradation process shows the effectiveness of the combined Photo-Fenton and electrocoagulation approach in removal of amoxicillin. Keywords: Pharmaceutical, Amoxicillin, Advanced Oxidation Processes; photo-Fenton; optimization; Electrocoagulation 2024-02-01T00:00:00Z