Nurelegne Shibeshi - Academia.edu (original) (raw)

Papers by Nurelegne Shibeshi

Research paper thumbnail of Household defluoridation unit design and development

Zede Journal, 2007

The 1984 World Health Organization (WHO) guidelines suggest the permissible jluoride concentratio... more The 1984 World Health Organization (WHO) guidelines suggest the permissible jluoride concentration in drinking water to be l. 0 mg/l in warm climate and 1. 2 mg/! in cooler areas. Excessive jluoride intake causes an irreversible health problem widely known as jluorosis. There are three stages ofjluorisis' Dental, skeletal and crippling jluorosis and all of them are known to prevail in Ethiopia. In the sample areas in this project the jluoride concentration lies between 3.4 and 24.3 mg/!. The objective of this paper is to present the result of a research aimed at designing and developing a household dejluoridiation unit that is simple, inexpensive and that uses locally manufactured Aluminum Sulfate that will reduce the jluoride concentration to the recommended range. The dejluoridation unit developed by the researchers is simple, just a bucket with a tap. The bucket can be produced from plastic, clay or metal. A sample defluoridiation unit has been developed in the Chemical Engineering laboratory with a plastic bucket and it has been checked to be effective. For the sample produced in the laboratory the cost is around 25 Birr, just the cost of the bucket and the tap. The cost of locally produced Aluminum Sulfate and lime is 2. 5 Birr/Kg and and 1 Birr/ Kg respectively, hence the total cost of chemicals for treating a 20 liter bucket of water is less than 10 cents.

Research paper thumbnail of Entwicklung und Selektion kinetischer Modelle radikalischer Polymerisationen bis zu hohen Monomerumsätzen

Research paper thumbnail of Isolation and screening of low-density polyethylene (LDPE) bags degrading bacteria from Addis Ababa municipal solid waste disposal site “Koshe”

Annals of Microbiology, Jan 19, 2023

Purpose This study aims to screen bacterial isolates from the Addis Ababa municipal solid waste d... more Purpose This study aims to screen bacterial isolates from the Addis Ababa municipal solid waste dumping site (Koshe) for the biodegradation of low-density polyethylene bags and analyzes their efficiency in degrading plastic bags. Methods In this study, low-density polyethylene bag-degrading bacteria were isolated from the Koshe municipal solid waste disposal area in Addis Ababa, Ethiopia. Screening of isolates for low-density polyethylene bag biodegradation was carried out using a clear zone method. Additionally, the efficiency of the isolates for low-density polyethylene biodegradation was evaluated using the weight loss method, scanning electron microscopy analysis, and Fourier transform infrared analysis. Finally, molecular identification of potential low-density polyethylene degrader bacterial isolates was done by 16S rDNA sequencing. Results Isolates KS35, KS14, and KS119 resulted in significant weight loss of low-density polyethylene film (42.87 ± 1.91%, 37.2 ± 3.06%, and 23.87 ± 0.11% weight loss, respectively). These isolates were selected for further biodegradation study using scanning electron microscopy and Fourier transform infrared analysis. Scanning electron microscopy analysis shows the formation of pores, pits, and distortion of the plastic surface. Fourier transform infrared analysis indicates the appearance of new peaks at the surface of low-density polyethylene films. Phylogenetic analysis of the three potential bacterial isolates was also carried out, and the result indicates that the sequence of isolate KS35 had 99% similarity with sequences of Methylobacterium radiotolerans MN525302. Isolate KS119 had 100% similarity with Methylobacterium fujisawaense KT720189, and the sequence of isolate KS14 had 99% similarity with species of Lysinibacillus fusiformis. Conclusions Weight loss, scanning electron microscopy analysis, and Fourier transform infrared analysis results show that isolates KS35, KS14, and KS119 have high potential in degrading low-density polyethylene bags.

Research paper thumbnail of COD and colour removal from molasses spent wash using activated carbon produced from bagasse fly ash of Matahara sugar factory, Oromiya region, Ethiopia

Water SA, Aug 2, 2017

The aim of this study was to investigate the removal of chemical oxygen demand (COD) and colour f... more The aim of this study was to investigate the removal of chemical oxygen demand (COD) and colour from a melanoidin solution using activated carbon produced from bagasse fly ash (BFA). Melanoidins are heterogeneous polymers and major contributors to the dark brown colour of molasses spent wash, which is an extensive cause of environment pollution. The surface area of the BFA was determined as 160.9 ± 2.8m²/g with 90% of particle less than 156.8 µm in size. Characterization of the BFA by Fourier transform infrared spectroscopy (FTIR) showed the presence of hydroxyl and carbonyl functional groups, whereas X-ray diffraction analysis indicated its amorphous nature. Moreover, scanning electron microscopy analysis showed a heterogeneous and irregular shape of pores. Among the adsorption isotherm models analysed, the Freundlich model fitted best to the experimental data, indicating a maximum adsorptive capacity of 124.80 mg/g. The removal of COD and colour from a melanoidin solution with this activated carbon was carried out using an experimental design taking 4 factors into account. These were adsorbent dose, contact time, pH and initial COD concentration, with removal of COD and colour as response variables. COD reduction was influenced by initial COD concentration whereas colour removal was dominated by contact time, which was in line with the findings of principal component analysis. The maximum COD removal recorded was 61.6% at the optimum condition of adsorbent dose of 4 g in 100 mL, contact time of 4 h, pH 8 and initial COD concentration 6 000 mg/L, whereas the decolourization of melanoidin solution was 64% at adsorbent dose of 4 g, contact time 4 h, pH 3 and initial COD concentration 6 000 mg/L. Hence, activated BFA is a promising option for simultaneous removal of COD and colour from molasses spent wash under the stated conditions.

Research paper thumbnail of Determination of Traffic Related Air Pollution Status Using Dispersion Modeling: The Case of Megenagna, Addis Ababa, Ethiopia

Research Square (Research Square), May 9, 2022

Tra c is now the leading cause of air pollution in growing megacities in the developing world. Be... more Tra c is now the leading cause of air pollution in growing megacities in the developing world. Because of unimproved old age of the car and poor road conditions in Ethiopia's capital city (Addis Ababa), vehicles are the main cause of air pollution. Megenagna (located between Bole and Yeka subcities of Addis Ababa) is one of the city's key hubs squares, with six major road intersections that cause overcrowding and tra c congestion. The objective of this study was to measure and predict air pollution levels in the Megenagna area using the dispersion model (AERMOD). A 43 sampling points were selected with a sample campaign for two months (January and February) was conducted. Particulate matter (PM 2.5 and PM 10) and gaseous pollutants (SO 2 and NO 2) were monitored with hand-held Air-test Model-CW-HAT2005 and Aeroqual series 5000, respectively. The difference among sampling locations was statistically signi cant (p < 0.05), indicating that there is signi cant spatial variation throughout the study site. The sensitivity change of wind speed 1 m/sec and wind direction 45 0 in the self-monitored sample site was best tting for the prediction, calibration, and validation of pollutants in AERMOD. Particulate matter and gaseous pollutants were predicted to vary from sight to sight, with SO 2 above the standard value. This study shows that tra c-related emissions in Addis Ababa should be investigated further in terms of spatiotemporal variation.

Research paper thumbnail of Synthesis of Polyaluminum Chloride: Optimization of Process Parameters, Characterization and Performance Investigation for Water Treatment

Research paper thumbnail of KNO3-Loaded Coffee Husk Ash as a Heterogeneous Alkali Catalyst for Waste Frying Oil Valorization into Biodiesel

ACS Omega

In this study, a heterogeneous basic catalyst was synthesized from a catalyst composite material ... more In this study, a heterogeneous basic catalyst was synthesized from a catalyst composite material (CCM) of coffee husk ash and char mixture (A/C) impregnated with KNO 3 and employed to transesterify crude waste frying oil (WFO). The effect of CCM calcination temperature (CCMCT) (500−700°C) on the catalyst physicochemical properties was investigated. A differential scanning calorimeter was used to examine potential phase changes during the calcination of A/C and CCM. The catalysts from each CCMCT were characterized by X-ray diffraction (XRD), Brunauer−Emmet−Teller surface area analyzer, scanning electron microscopy (SEM), SEM with energy-dispersive X-ray diffractometer, colorimeter, and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrometer. The methoxy functional group FTIR peak integral value and the dynamic viscosity of the biodiesel synthesized by each catalyst were used to determine the qualitative WFO conversion. Furthermore, the quantitative WFO conversion was determined using nuclear magnetic resonance (1 H NMR) analysis. Crystallinity, elemental composition, basicity, and morphology of catalysts were highly dependent on the CCMCT. Without transesterification condition optimization (reaction temperature of 45 ± 2.5°C, catalyst loading of 3 wt %, methanol to oil molar ratio of 12:1, and reaction time of 1 h), a higher catalytic performance (72.04% WFO conversion) was reached using a catalyst from the CCMCT of 600°C. When using a coffee husk ash catalyst without KNO 3 impregnation (C-00-600), the WFO conversion was only 52.92%. When comparing the C-25-600 and C-00-600 catalysts, it was observed that KNO 3 impregnation had a substantial impact on the catalyst crystallinity, basicity, and morphology.

Research paper thumbnail of Heterogeneous Catalysts from Metallic Oxides and Lignocellulosic Biomasses Ash for the Valorization of Feedstocks into Biodiesel: an Overview

Bioenergy Research, Dec 8, 2022

Research paper thumbnail of Kinetic analysis of dehydroxylation of Ethiopian kaolinite during calcination

Journal of Thermal Analysis and Calorimetry

Research paper thumbnail of Characteristic Investigations on Ethiopian Kaolinite: Effect of Calcination Temperature on Pozzolanic Activity and Specific Surface Area

Advances in Materials Science and Engineering

Kaolinite, a clay mineral, is an important industrial mineral which was gainfully utilized with s... more Kaolinite, a clay mineral, is an important industrial mineral which was gainfully utilized with several industrial significances. Towards mineral beneficiation, the present study aimed to investigate the effect of calcination temperature on the pozzolanic activity and specific surface area of Ethiopian kaolinite (Ek). The raw Ek and calcined Ek were characterized using different sophisticated techniques, such as XRD, FTIR, DSC, TGA, dynamic light scattering, electrophoretic light scattering, and SEM analysis. The pozzolanic activity and specific surface area of Ek particles were ascertained using Chapelle’s and Brunauer–Emmett–Teller methods, respectively, with some modifications. The results revealed that the calcination temperature had a great influence on pozzolanic activity and specific surface area of Ek. It was observed that the pozzolanic activity linearly increased with calcination temperature until 700°C and showed a maximal value of 1235 mg Ca(OH)2 g−1. On the other hand, ...

Research paper thumbnail of Kinetic Analysis of Aluminum Extraction from Ethiopian Kaolinite Using Hydrochloric Acid

International Journal of Chemical Engineering

The aim of this study was kinetic investigations of aluminum extraction from Ethiopian kaolinite ... more The aim of this study was kinetic investigations of aluminum extraction from Ethiopian kaolinite with hydrochloric acid. The effects of extraction parameters, namely, solid-to-liquid ratio (0.05, 0.075, 0.100, and 0.125 g·mL−1), acid concentrations (2, 3, 4, and 5 M), reaction temperature (50, 60, 70, and 80°C), and time (20, 40, 60, 80, 100, 120, 140, 160, and 180 min), on yield of aluminum were investigated. The results revealed that the extraction yield of aluminum increased with increase of acid concentration, reaction temperature, and time and declined with increase of solid-to-liquid ratio. The kinetic analysis of aluminum extraction was evaluated using pseudohomogeneous, nucleation growth (Avrami), and shrinking core models. The results showed that kinetics of aluminum extraction were controlled by surface chemical reaction. The experimental results were well fitted by the shrinking core model of surface chemical reaction with first-order rate. The activation energy and the p...

Research paper thumbnail of Extraction, recovery and characterization of aluminum chloride from Ethiopian kaolin by leaching and crystallization

Research paper thumbnail of Entwicklung und Selektion kinetischer Modelle radikalischer Polymerisationen bis zu hohen Monomerumsätzen

Research paper thumbnail of Characterization and Optimization of Calcination Process Parameters for Extraction of Aluminum from Ethiopian Kaolinite

International Journal of Chemical Engineering, 2022

The present study aimed to optimize the calcination process parameters (viz., temperature, time, ... more The present study aimed to optimize the calcination process parameters (viz., temperature, time, and particles size) for the extraction of aluminum from Ethiopian kaolinite. The kaolinite calcination was done in the temperature of 600–700°C, time of 120–180 min, and particles size of 106–355 μm. The extraction of aluminum from calcined kaolinite was carried out at fixed acid concentration of 3 M, temperature of 80°C, liquid-to-solid ratio of 12 mL g−1, time of 120 min, and stirring speed of 700 rpm. The chemical composition of kaolinite was determined using XRF. Moreover, kaolinite, metakaolinite, and extracted aluminum were characterized by XRD, TGA, DSC, and FTIR. The XRF result of the kaolinite was mainly silicon oxide (55.76% w/w), aluminum oxide (32.02% w/w), and loss on ignition (11.17% w/w). Calcination of kaolinite produced amorphous metakaolinite due to the dehydroxylation reaction as shown by the FTIR results. Three endothermic peaks and one exothermic peak were detected i...

Research paper thumbnail of COD and colour removal from molasses spent wash using activated carbon produced from bagasse fly ash of Matahara sugar factory, Oromiya region, Ethiopia

Water SA, 2017

The aim of this study was to investigate the removal of chemical oxygen demand (COD) and colour f... more The aim of this study was to investigate the removal of chemical oxygen demand (COD) and colour from a melanoidin solution using activated carbon produced from bagasse fly ash (BFA). Melanoidins are heterogeneous polymers and major contributors to the dark brown colour of molasses spent wash, which is an extensive cause of environment pollution. The surface area of the BFA was determined as 160.9 ± 2.8m²/g with 90% of particle less than 156.8 µm in size. Characterization of the BFA by Fourier transform infrared spectroscopy (FTIR) showed the presence of hydroxyl and carbonyl functional groups, whereas X-ray diffraction analysis indicated its amorphous nature. Moreover, scanning electron microscopy analysis showed a heterogeneous and irregular shape of pores. Among the adsorption isotherm models analysed, the Freundlich model fitted best to the experimental data, indicating a maximum adsorptive capacity of 124.80 mg/g. The removal of COD and colour from a melanoidin solution with this activated carbon was carried out using an experimental design taking 4 factors into account. These were adsorbent dose, contact time, pH and initial COD concentration, with removal of COD and colour as response variables. COD reduction was influenced by initial COD concentration whereas colour removal was dominated by contact time, which was in line with the findings of principal component analysis. The maximum COD removal recorded was 61.6% at the optimum condition of adsorbent dose of 4 g in 100 mL, contact time of 4 h, pH 8 and initial COD concentration 6 000 mg/L, whereas the decolourization of melanoidin solution was 64% at adsorbent dose of 4 g, contact time 4 h, pH 3 and initial COD concentration 6 000 mg/L. Hence, activated BFA is a promising option for simultaneous removal of COD and colour from molasses spent wash under the stated conditions.

Research paper thumbnail of An Integrated Treatment Technology for Blended Wastewater of the Sugar Industry and Ethanol Distillery

Environmental Processes, Mar 22, 2019

This study was designed to evaluate physicochemical properties of the sugar industry and ethanol ... more This study was designed to evaluate physicochemical properties of the sugar industry and ethanol distillery wastewater, and treat the blended wastewater of the two industries using anaerobic digestion followed by adsorption of bagasse fly ash (BFA). The wastewater samples of the two industries were collected using composite and grab-sampling techniques. The application of the integrated treatment method was performed using an initial COD concentration of 10,000 mg/L, at the hydraulic retention time of 10 days, pH 7 and a constant temperature (37°C) of the bioreactor, whereas the adsorption treatment was operated at the optimum point of BFA dose (4 g in 100 mL) and contact time (4 h) obtained in previous studies. Most of the physicochemical parameters of the two wastewaters were above the effluent discharging limits, which have the potential to cause adverse effects on the environment by interfering with physicochemical and biological processing. Under anaerobic treatment, maximum COD reduction of 65% and color removal of 79% were recorded, whereas after adsorption treatment, COD reduction of 62% and color removal of 58% were observed. However, the integration of the two aforementioned treatment technologies resulted in an average COD reduction of 76% and color removal of 83%, which indicates a promising option to mitigate pollution of untreated wastewater and enhance the practices of reusing the treated wastewater at the industrial scales. Finally, it can be concluded that the treated effluent can also be reused for irrigation of sugarcane which will contribute to sustainable water utilization in the sector.

Research paper thumbnail of Characteristic Investigations on Ethiopian Kaolinite: Effect of Calcination Temperature on Pozzolanic Activity and Specific Surface Area

Advances in Materials Science and Engineering

Kaolinite, a clay mineral, is an important industrial mineral which was gainfully utilized with s... more Kaolinite, a clay mineral, is an important industrial mineral which was gainfully utilized with several industrial significances. Towards mineral beneficiation, the present study aimed to investigate the effect of calcination temperature on the pozzolanic activity and specific surface area of Ethiopian kaolinite (Ek). The raw Ek and calcined Ek were characterized using different sophisticated techniques, such as XRD, FTIR, DSC, TGA, dynamic light scattering, electrophoretic light scattering, and SEM analysis. The pozzolanic activity and specific surface area of Ek particles were ascertained using Chapelle’s and Brunauer–Emmett–Teller methods, respectively, with some modifications. The results revealed that the calcination temperature had a great influence on pozzolanic activity and specific surface area of Ek. It was observed that the pozzolanic activity linearly increased with calcination temperature until 700°C and showed a maximal value of 1235 mg Ca(OH)2 g−1. On the other hand, ...

Research paper thumbnail of Household defluoridation unit design and development

Zede Journal, 2007

The 1984 World Health Organization (WHO) guidelines suggest the permissible jluoride concentratio... more The 1984 World Health Organization (WHO) guidelines suggest the permissible jluoride concentration in drinking water to be l. 0 mg/l in warm climate and 1. 2 mg/! in cooler areas. Excessive jluoride intake causes an irreversible health problem widely known as jluorosis. There are three stages ofjluorisis' Dental, skeletal and crippling jluorosis and all of them are known to prevail in Ethiopia. In the sample areas in this project the jluoride concentration lies between 3.4 and 24.3 mg/!. The objective of this paper is to present the result of a research aimed at designing and developing a household dejluoridiation unit that is simple, inexpensive and that uses locally manufactured Aluminum Sulfate that will reduce the jluoride concentration to the recommended range. The dejluoridation unit developed by the researchers is simple, just a bucket with a tap. The bucket can be produced from plastic, clay or metal. A sample defluoridiation unit has been developed in the Chemical Engineering laboratory with a plastic bucket and it has been checked to be effective. For the sample produced in the laboratory the cost is around 25 Birr, just the cost of the bucket and the tap. The cost of locally produced Aluminum Sulfate and lime is 2. 5 Birr/Kg and and 1 Birr/ Kg respectively, hence the total cost of chemicals for treating a 20 liter bucket of water is less than 10 cents.

Research paper thumbnail of Entwicklung und Selektion kinetischer Modelle radikalischer Polymerisationen bis zu hohen Monomerumsätzen

Research paper thumbnail of Isolation and screening of low-density polyethylene (LDPE) bags degrading bacteria from Addis Ababa municipal solid waste disposal site “Koshe”

Annals of Microbiology, Jan 19, 2023

Purpose This study aims to screen bacterial isolates from the Addis Ababa municipal solid waste d... more Purpose This study aims to screen bacterial isolates from the Addis Ababa municipal solid waste dumping site (Koshe) for the biodegradation of low-density polyethylene bags and analyzes their efficiency in degrading plastic bags. Methods In this study, low-density polyethylene bag-degrading bacteria were isolated from the Koshe municipal solid waste disposal area in Addis Ababa, Ethiopia. Screening of isolates for low-density polyethylene bag biodegradation was carried out using a clear zone method. Additionally, the efficiency of the isolates for low-density polyethylene biodegradation was evaluated using the weight loss method, scanning electron microscopy analysis, and Fourier transform infrared analysis. Finally, molecular identification of potential low-density polyethylene degrader bacterial isolates was done by 16S rDNA sequencing. Results Isolates KS35, KS14, and KS119 resulted in significant weight loss of low-density polyethylene film (42.87 ± 1.91%, 37.2 ± 3.06%, and 23.87 ± 0.11% weight loss, respectively). These isolates were selected for further biodegradation study using scanning electron microscopy and Fourier transform infrared analysis. Scanning electron microscopy analysis shows the formation of pores, pits, and distortion of the plastic surface. Fourier transform infrared analysis indicates the appearance of new peaks at the surface of low-density polyethylene films. Phylogenetic analysis of the three potential bacterial isolates was also carried out, and the result indicates that the sequence of isolate KS35 had 99% similarity with sequences of Methylobacterium radiotolerans MN525302. Isolate KS119 had 100% similarity with Methylobacterium fujisawaense KT720189, and the sequence of isolate KS14 had 99% similarity with species of Lysinibacillus fusiformis. Conclusions Weight loss, scanning electron microscopy analysis, and Fourier transform infrared analysis results show that isolates KS35, KS14, and KS119 have high potential in degrading low-density polyethylene bags.

Research paper thumbnail of COD and colour removal from molasses spent wash using activated carbon produced from bagasse fly ash of Matahara sugar factory, Oromiya region, Ethiopia

Water SA, Aug 2, 2017

The aim of this study was to investigate the removal of chemical oxygen demand (COD) and colour f... more The aim of this study was to investigate the removal of chemical oxygen demand (COD) and colour from a melanoidin solution using activated carbon produced from bagasse fly ash (BFA). Melanoidins are heterogeneous polymers and major contributors to the dark brown colour of molasses spent wash, which is an extensive cause of environment pollution. The surface area of the BFA was determined as 160.9 ± 2.8m²/g with 90% of particle less than 156.8 µm in size. Characterization of the BFA by Fourier transform infrared spectroscopy (FTIR) showed the presence of hydroxyl and carbonyl functional groups, whereas X-ray diffraction analysis indicated its amorphous nature. Moreover, scanning electron microscopy analysis showed a heterogeneous and irregular shape of pores. Among the adsorption isotherm models analysed, the Freundlich model fitted best to the experimental data, indicating a maximum adsorptive capacity of 124.80 mg/g. The removal of COD and colour from a melanoidin solution with this activated carbon was carried out using an experimental design taking 4 factors into account. These were adsorbent dose, contact time, pH and initial COD concentration, with removal of COD and colour as response variables. COD reduction was influenced by initial COD concentration whereas colour removal was dominated by contact time, which was in line with the findings of principal component analysis. The maximum COD removal recorded was 61.6% at the optimum condition of adsorbent dose of 4 g in 100 mL, contact time of 4 h, pH 8 and initial COD concentration 6 000 mg/L, whereas the decolourization of melanoidin solution was 64% at adsorbent dose of 4 g, contact time 4 h, pH 3 and initial COD concentration 6 000 mg/L. Hence, activated BFA is a promising option for simultaneous removal of COD and colour from molasses spent wash under the stated conditions.

Research paper thumbnail of Determination of Traffic Related Air Pollution Status Using Dispersion Modeling: The Case of Megenagna, Addis Ababa, Ethiopia

Research Square (Research Square), May 9, 2022

Tra c is now the leading cause of air pollution in growing megacities in the developing world. Be... more Tra c is now the leading cause of air pollution in growing megacities in the developing world. Because of unimproved old age of the car and poor road conditions in Ethiopia's capital city (Addis Ababa), vehicles are the main cause of air pollution. Megenagna (located between Bole and Yeka subcities of Addis Ababa) is one of the city's key hubs squares, with six major road intersections that cause overcrowding and tra c congestion. The objective of this study was to measure and predict air pollution levels in the Megenagna area using the dispersion model (AERMOD). A 43 sampling points were selected with a sample campaign for two months (January and February) was conducted. Particulate matter (PM 2.5 and PM 10) and gaseous pollutants (SO 2 and NO 2) were monitored with hand-held Air-test Model-CW-HAT2005 and Aeroqual series 5000, respectively. The difference among sampling locations was statistically signi cant (p < 0.05), indicating that there is signi cant spatial variation throughout the study site. The sensitivity change of wind speed 1 m/sec and wind direction 45 0 in the self-monitored sample site was best tting for the prediction, calibration, and validation of pollutants in AERMOD. Particulate matter and gaseous pollutants were predicted to vary from sight to sight, with SO 2 above the standard value. This study shows that tra c-related emissions in Addis Ababa should be investigated further in terms of spatiotemporal variation.

Research paper thumbnail of Synthesis of Polyaluminum Chloride: Optimization of Process Parameters, Characterization and Performance Investigation for Water Treatment

Research paper thumbnail of KNO3-Loaded Coffee Husk Ash as a Heterogeneous Alkali Catalyst for Waste Frying Oil Valorization into Biodiesel

ACS Omega

In this study, a heterogeneous basic catalyst was synthesized from a catalyst composite material ... more In this study, a heterogeneous basic catalyst was synthesized from a catalyst composite material (CCM) of coffee husk ash and char mixture (A/C) impregnated with KNO 3 and employed to transesterify crude waste frying oil (WFO). The effect of CCM calcination temperature (CCMCT) (500−700°C) on the catalyst physicochemical properties was investigated. A differential scanning calorimeter was used to examine potential phase changes during the calcination of A/C and CCM. The catalysts from each CCMCT were characterized by X-ray diffraction (XRD), Brunauer−Emmet−Teller surface area analyzer, scanning electron microscopy (SEM), SEM with energy-dispersive X-ray diffractometer, colorimeter, and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrometer. The methoxy functional group FTIR peak integral value and the dynamic viscosity of the biodiesel synthesized by each catalyst were used to determine the qualitative WFO conversion. Furthermore, the quantitative WFO conversion was determined using nuclear magnetic resonance (1 H NMR) analysis. Crystallinity, elemental composition, basicity, and morphology of catalysts were highly dependent on the CCMCT. Without transesterification condition optimization (reaction temperature of 45 ± 2.5°C, catalyst loading of 3 wt %, methanol to oil molar ratio of 12:1, and reaction time of 1 h), a higher catalytic performance (72.04% WFO conversion) was reached using a catalyst from the CCMCT of 600°C. When using a coffee husk ash catalyst without KNO 3 impregnation (C-00-600), the WFO conversion was only 52.92%. When comparing the C-25-600 and C-00-600 catalysts, it was observed that KNO 3 impregnation had a substantial impact on the catalyst crystallinity, basicity, and morphology.

Research paper thumbnail of Heterogeneous Catalysts from Metallic Oxides and Lignocellulosic Biomasses Ash for the Valorization of Feedstocks into Biodiesel: an Overview

Bioenergy Research, Dec 8, 2022

Research paper thumbnail of Kinetic analysis of dehydroxylation of Ethiopian kaolinite during calcination

Journal of Thermal Analysis and Calorimetry

Research paper thumbnail of Characteristic Investigations on Ethiopian Kaolinite: Effect of Calcination Temperature on Pozzolanic Activity and Specific Surface Area

Advances in Materials Science and Engineering

Kaolinite, a clay mineral, is an important industrial mineral which was gainfully utilized with s... more Kaolinite, a clay mineral, is an important industrial mineral which was gainfully utilized with several industrial significances. Towards mineral beneficiation, the present study aimed to investigate the effect of calcination temperature on the pozzolanic activity and specific surface area of Ethiopian kaolinite (Ek). The raw Ek and calcined Ek were characterized using different sophisticated techniques, such as XRD, FTIR, DSC, TGA, dynamic light scattering, electrophoretic light scattering, and SEM analysis. The pozzolanic activity and specific surface area of Ek particles were ascertained using Chapelle’s and Brunauer–Emmett–Teller methods, respectively, with some modifications. The results revealed that the calcination temperature had a great influence on pozzolanic activity and specific surface area of Ek. It was observed that the pozzolanic activity linearly increased with calcination temperature until 700°C and showed a maximal value of 1235 mg Ca(OH)2 g−1. On the other hand, ...

Research paper thumbnail of Kinetic Analysis of Aluminum Extraction from Ethiopian Kaolinite Using Hydrochloric Acid

International Journal of Chemical Engineering

The aim of this study was kinetic investigations of aluminum extraction from Ethiopian kaolinite ... more The aim of this study was kinetic investigations of aluminum extraction from Ethiopian kaolinite with hydrochloric acid. The effects of extraction parameters, namely, solid-to-liquid ratio (0.05, 0.075, 0.100, and 0.125 g·mL−1), acid concentrations (2, 3, 4, and 5 M), reaction temperature (50, 60, 70, and 80°C), and time (20, 40, 60, 80, 100, 120, 140, 160, and 180 min), on yield of aluminum were investigated. The results revealed that the extraction yield of aluminum increased with increase of acid concentration, reaction temperature, and time and declined with increase of solid-to-liquid ratio. The kinetic analysis of aluminum extraction was evaluated using pseudohomogeneous, nucleation growth (Avrami), and shrinking core models. The results showed that kinetics of aluminum extraction were controlled by surface chemical reaction. The experimental results were well fitted by the shrinking core model of surface chemical reaction with first-order rate. The activation energy and the p...

Research paper thumbnail of Extraction, recovery and characterization of aluminum chloride from Ethiopian kaolin by leaching and crystallization

Research paper thumbnail of Entwicklung und Selektion kinetischer Modelle radikalischer Polymerisationen bis zu hohen Monomerumsätzen

Research paper thumbnail of Characterization and Optimization of Calcination Process Parameters for Extraction of Aluminum from Ethiopian Kaolinite

International Journal of Chemical Engineering, 2022

The present study aimed to optimize the calcination process parameters (viz., temperature, time, ... more The present study aimed to optimize the calcination process parameters (viz., temperature, time, and particles size) for the extraction of aluminum from Ethiopian kaolinite. The kaolinite calcination was done in the temperature of 600–700°C, time of 120–180 min, and particles size of 106–355 μm. The extraction of aluminum from calcined kaolinite was carried out at fixed acid concentration of 3 M, temperature of 80°C, liquid-to-solid ratio of 12 mL g−1, time of 120 min, and stirring speed of 700 rpm. The chemical composition of kaolinite was determined using XRF. Moreover, kaolinite, metakaolinite, and extracted aluminum were characterized by XRD, TGA, DSC, and FTIR. The XRF result of the kaolinite was mainly silicon oxide (55.76% w/w), aluminum oxide (32.02% w/w), and loss on ignition (11.17% w/w). Calcination of kaolinite produced amorphous metakaolinite due to the dehydroxylation reaction as shown by the FTIR results. Three endothermic peaks and one exothermic peak were detected i...

Research paper thumbnail of COD and colour removal from molasses spent wash using activated carbon produced from bagasse fly ash of Matahara sugar factory, Oromiya region, Ethiopia

Water SA, 2017

The aim of this study was to investigate the removal of chemical oxygen demand (COD) and colour f... more The aim of this study was to investigate the removal of chemical oxygen demand (COD) and colour from a melanoidin solution using activated carbon produced from bagasse fly ash (BFA). Melanoidins are heterogeneous polymers and major contributors to the dark brown colour of molasses spent wash, which is an extensive cause of environment pollution. The surface area of the BFA was determined as 160.9 ± 2.8m²/g with 90% of particle less than 156.8 µm in size. Characterization of the BFA by Fourier transform infrared spectroscopy (FTIR) showed the presence of hydroxyl and carbonyl functional groups, whereas X-ray diffraction analysis indicated its amorphous nature. Moreover, scanning electron microscopy analysis showed a heterogeneous and irregular shape of pores. Among the adsorption isotherm models analysed, the Freundlich model fitted best to the experimental data, indicating a maximum adsorptive capacity of 124.80 mg/g. The removal of COD and colour from a melanoidin solution with this activated carbon was carried out using an experimental design taking 4 factors into account. These were adsorbent dose, contact time, pH and initial COD concentration, with removal of COD and colour as response variables. COD reduction was influenced by initial COD concentration whereas colour removal was dominated by contact time, which was in line with the findings of principal component analysis. The maximum COD removal recorded was 61.6% at the optimum condition of adsorbent dose of 4 g in 100 mL, contact time of 4 h, pH 8 and initial COD concentration 6 000 mg/L, whereas the decolourization of melanoidin solution was 64% at adsorbent dose of 4 g, contact time 4 h, pH 3 and initial COD concentration 6 000 mg/L. Hence, activated BFA is a promising option for simultaneous removal of COD and colour from molasses spent wash under the stated conditions.

Research paper thumbnail of An Integrated Treatment Technology for Blended Wastewater of the Sugar Industry and Ethanol Distillery

Environmental Processes, Mar 22, 2019

This study was designed to evaluate physicochemical properties of the sugar industry and ethanol ... more This study was designed to evaluate physicochemical properties of the sugar industry and ethanol distillery wastewater, and treat the blended wastewater of the two industries using anaerobic digestion followed by adsorption of bagasse fly ash (BFA). The wastewater samples of the two industries were collected using composite and grab-sampling techniques. The application of the integrated treatment method was performed using an initial COD concentration of 10,000 mg/L, at the hydraulic retention time of 10 days, pH 7 and a constant temperature (37°C) of the bioreactor, whereas the adsorption treatment was operated at the optimum point of BFA dose (4 g in 100 mL) and contact time (4 h) obtained in previous studies. Most of the physicochemical parameters of the two wastewaters were above the effluent discharging limits, which have the potential to cause adverse effects on the environment by interfering with physicochemical and biological processing. Under anaerobic treatment, maximum COD reduction of 65% and color removal of 79% were recorded, whereas after adsorption treatment, COD reduction of 62% and color removal of 58% were observed. However, the integration of the two aforementioned treatment technologies resulted in an average COD reduction of 76% and color removal of 83%, which indicates a promising option to mitigate pollution of untreated wastewater and enhance the practices of reusing the treated wastewater at the industrial scales. Finally, it can be concluded that the treated effluent can also be reused for irrigation of sugarcane which will contribute to sustainable water utilization in the sector.

Research paper thumbnail of Characteristic Investigations on Ethiopian Kaolinite: Effect of Calcination Temperature on Pozzolanic Activity and Specific Surface Area

Advances in Materials Science and Engineering

Kaolinite, a clay mineral, is an important industrial mineral which was gainfully utilized with s... more Kaolinite, a clay mineral, is an important industrial mineral which was gainfully utilized with several industrial significances. Towards mineral beneficiation, the present study aimed to investigate the effect of calcination temperature on the pozzolanic activity and specific surface area of Ethiopian kaolinite (Ek). The raw Ek and calcined Ek were characterized using different sophisticated techniques, such as XRD, FTIR, DSC, TGA, dynamic light scattering, electrophoretic light scattering, and SEM analysis. The pozzolanic activity and specific surface area of Ek particles were ascertained using Chapelle’s and Brunauer–Emmett–Teller methods, respectively, with some modifications. The results revealed that the calcination temperature had a great influence on pozzolanic activity and specific surface area of Ek. It was observed that the pozzolanic activity linearly increased with calcination temperature until 700°C and showed a maximal value of 1235 mg Ca(OH)2 g−1. On the other hand, ...