Agroforestry farming system comprises considerable cultivated land area in the tropics. Despite t... more Agroforestry farming system comprises considerable cultivated land area in the tropics. Despite the economic and social benefits of the system for farmers, it is also known to have an important role in the conservation of tree species. This study aims to evaluate the composition and distribution of tree species in coffee based agroforestry system to determine the potential for biodiversity conservation. To address the objective of this study, 57 sample plots in farmers' coffee field and 12 sample plots in forest reserve were surveyed in Eastern Uganda. The result shows that the number of indigenous tree species in coffee farms was lower than that of forest reserve. Similarly, tree species richness per plot, Shannon and Simpson diversity indexes of forest reserve were significantly (p<0.05) higher than that of coffee farms. However, with the inclusion of exotic tree species, coffee farms were found to be significantly higher than that of forest reserve for the above diversity indexes. On the other hand, the distribution of tree species in the coffee farms were mainly dominated by few tree species indicating the need for measures that ensure the sustainability of those less represented tree species.
Applied Journal of Environmental Engineering Science, Dec 30, 2019
The main objective of the study is to analysis sustainability of water supply and distribution sy... more The main objective of the study is to analysis sustainability of water supply and distribution system of Asossa town. While conducting this research, both primary and secondary data were collected and software such as water GEMSV8i, ArcGIS version10.4.1 and GPS Garmin72 were used. The water supply source of the study area yields 46.1 l/s but only 23.6 l/s of water used. The simulated result of extended period simulation showed that the performance of hydraulic parameters were pressure 21.05 % for pressure value <15 m, 72.8 % for pressure value 15-60 m and 6.15 % for pressure value >60 m head and the velocity of pipe flow showed that 84.86 % for velocity <0.6 m/s, 15.14 % for velocity range 0.6-2 m/s. Based on the simulated result, reliability value 0.728 and 0.151, vulnerability value 0.251 and 0.538 and resiliency value 0.322 and 0.1 were obtained for both pressure and velocity, respectively. The overall sustainability index was 0.375 but 0.19 for velocity and 0.559 for pressure. Therefore, sustainability of existing water supply and distribution system of Assosa town is not sustainable. It is mandatory to redesign the Assosa town water supply and distribution system in order to make it sustainable.
International Journal of Analytical Chemistry, Sep 29, 2022
Water treatment is the primary consideration before utilizing water for di erent purposes. Surfac... more Water treatment is the primary consideration before utilizing water for di erent purposes. Surface water is highly vulnerable to pollution, either due to natural or anthropogenic processes. e main targets of this study were to investigate surface water treatment using Moringa Oleifera (MO), the electrocoagulation process (EC), and the Moringa Oleifera assisted electrocoagulation process (MOAEC). e Moringa Oleifera, EC process, and Moringa Oleifera-assisted EC process are e ective mechanisms for the removal of COD (Chemical Oxygen Demand), BOD (Biological Oxygen Demand), TDS (Total Dissolved Solids), phosphate, TSS (Total Suspended Solids), and color from surface water. Di erent operating parameters such as pH (5-11), the dosage of coagulant (0.2-0.5 g), contact time or reaction time (20-50 minutes), current (0.2-0.5 A), and settling time (5-20 minutes) were considered. e maximum removal e ciency using Moringa Oleifera and the EC process was COD (85.48%), BOD (78.50%), TDS (84.5%), phosphate (95.70%), TSS (93.90%), color (94.50%), and COD (90.50%), BOD (87%), TDS (97.50%), phosphate (89.10%), TSS (95.80%), and color (96.15%), respectively. Similarly, with the application of MOAEC, 91.47%, 89.35%, 97.0%, 90.20%, 9.10%, and 95.70% of COD, BOD, TDS, phosphate, TSS, and color were removed, respectively. e EC process and MOAEC were more e ective in the removal of COD, BOD, TDS, TSS, and color than using MO. More phosphate was removed using MO than the EC process and MOAEC. Additionally, the e ects of di erent operating parameters were studied on the removal e ciency.
In this study, the treatment of landfill leachate by sono (US) and photo (UV) based advanced oxid... more In this study, the treatment of landfill leachate by sono (US) and photo (UV) based advanced oxidation processes (AOPs) was investigated in terms of % color and COD removal, together with electrical energy per order. Experimental results showed that, the hybrid sono-photo-Fenton (US/UV/Fe 2+ / H 2 O 2) process has shown that higher removal of color (100%) and COD (96%) with required of low electrical energy per order (0.71 kWh/m 3) than the other processes. The influence of various experimental parameters such as H 2 O 2 and Fe 2+ concentration, COD concentration, solution pH, sonication (US) and photo (UV) power on the % color and COD removal with electrical energy per order has been studied to find out the optimum conditions leading to maximum % removal efficiency of hybrid US/UV/Fe 2+ /H 2 O 2 process. The best results of US/UV/Fe 2+ /H 2 O 2 process of landfill leachate have been obtained using 80 mM of H 2 O 2 , 40 mM of Fe 2+ , pH of 3, COD concentration of 2,000 ppm, sonication power of 100 W and UV power of 32 W and after 3 h of reaction time. The synergy index between sonication (US) and photo-Fenton (UV/Fe 2+ /H 2 O 2) process has been studied and critically reported. Therefore, the combination of US and UV based AOPs has been proved to be efficient treatment techniques for removal of pollutant from industrial effluent and wastewater.
In order to lower the high prices of individual feedstock, extend the life of a more limited feed... more In order to lower the high prices of individual feedstock, extend the life of a more limited feedstock and to improve the fuel properties of biodiesel it imperative to optimize process parameters for biodiesel derived from mixed feedstocks. Samples of castor seeds were collected from Jimma zone, southwest Ethiopia while sample of wet microalgal biomass was obtained from wastewater stabilization ponds using a 60 µm filter screen. The castor seeds and microalgal biomass were sun-dried before further dried in an oven and ground to pastes. Oils were extracted from dry and milled castor seeds and microalgae pastes with a Soxhlet apparatus using methanol. The extracted oil was purified, mixed in 1:1 ratio and characterized before converted to biodiesel. A transesterification process designed using RSM based on CCD experimental design was used to optimize the production process parameters using alkaline catalyst. The Design Expert® 12 software was used to analysis the experimental results. The effects of catalyst concentration, ethanol to oil molar ratio and reaction temperature on the yield of biodiesel were investigated using the experimental results. The optimum conditions for biodiesel production from mixed oil were a catalyst concentration of 1.23%, alcohol to oil molar ratio of 5.94:1 and reaction temperature of 51.30 0 C. The yield of biodiesel under these conditions was 93.88%. Experiment was conducted under the specified optimum conditions to validate the result predicted. The yield of biodiesel from the experiment was 93.36% which is very close to the value predicted by the model. The fatty acid composition of the biodiesel was analyzed using GC. The fuel properties of biodiesel were determined according to procedures outlined in ASTM D6751 and EN 14214 standards. The physicochemical properties fulfill both standards.
Stringent discharge limits, high costs, and low removal efficiency of the conventional treatment ... more Stringent discharge limits, high costs, and low removal efficiency of the conventional treatment methods are facing challenges to handle industrial effluents containing heavy metals. The objective of this study was to use a recoverable magnetic zeolite to remove Cr(VI) from aqueous solution. The study investigated the application of nanotechnology to improve surface properties, recoverability, and adsorptive capacity of natural zeolite and the CCD-RSM-based optimization of adsorption process variables. Natural zeolites coated with various fractions of magnetic nanoparticles (25%, 33.33%, 50%, and 75%) were investigated for surface characters, adsorption capacity, removal efficiency, and recoverability. Natural zeolite coated with 33.33% (MZ33) was found a better adsorbent in terms of surface characters, adsorption capacity, and removal efficiency. Thirty batch adsorption experiments designed with CCD were carried out in order to optimize adsorption process variables using response surface methodology (RSM). It was found that adsorbent dose = 2 g/L, contact time = 75 min, initial CrðVIÞ concentration = 10 mg/L, and solution pH = 1:5 were the optimum conditions to achieve 93.57% Cr(VI) removal, which is very close to the experimental result of 94.88%. The adsorption isotherm determined from the operating parameters revealed that experimental data fit to the Langmuir isotherm model with R 2 = 0:9966 and maximum adsorption capacity = 43:933 mg/g. This proved that the adsorption of Cr(VI) on magnetic zeolite involved monolayer adsorption on the active sites. The separation factor, R L , value lies between 0 and 1 indicating that adsorption of Cr(VI) on the magnetic zeolite is favorable. The adsorption kinetics study follows pseudo-first order in the removal of Cr(VI). FTIR analysis of magnetic zeolite revealed the presence of numerous functional groups participating in Cr(VI) adsorption. The current study confirmed that magnetic zeolite is a cost-effective and favorable material for the removal of Cr(VI) from aqueous solution.
Applied and Environmental Soil Science, Jul 6, 2022
Plant growth-promoting rhizobacteria (PGPR) are an important bacterial resource as biofertilizers... more Plant growth-promoting rhizobacteria (PGPR) are an important bacterial resource as biofertilizers, which can promote plant growth and increase crop yields. In this study, isolation, characterization, and its e ect on plant promotion were assessed by isolating PGPR using soil samples collected from Jimma, Ethiopia. Out of 10 isolates, three of them (JEC3, JEC4, and JEC7) exhibited PSB traits in Pikovskaya media by solubilizing phosphate and producing IAA. Of the three isolates, JEC4 recorded the maximum phosphate solubilization index (4.98), soluble phosphate (283 μg/ml), and IAA production (10.21 μg/ml). e ndings of the isolates' morphological and biochemical tests showed that JEC3, JEC4, and JEC7 as Bacillus sp., Pseudomonas sp., and Enterobacter sp., respectively. e optimization of phosphate solubilization was done using di erent incubation times and sources of carbon and nitrogen. Furthermore, the isolate (JEC4) was tested for plant growth-promoting (PGP) activities and indicated the production of ammonia, hydrogen cyanide, and siderophore. JEC4 isolate showed a signi cant increase in sideways (%) seed germination, root and shoot length, fresh and dry weight of root, and shoot of maize in eld experiments than the untreated ones. e results indicate that the JEC4 isolate can be developed as a biological fertilizer for promoting crop productivity and ecosystem dynamics.
Agroforestry farming system comprises considerable cultivated land area in the tropics. Despite t... more Agroforestry farming system comprises considerable cultivated land area in the tropics. Despite the economic and social benefits of the system for farmers, it is also known to have an important role in the conservation of tree species. This study aims to evaluate the composition and distribution of tree species in coffee based agroforestry system to determine the potential for biodiversity conservation. To address the objective of this study, 57 sample plots in farmers' coffee field and 12 sample plots in forest reserve were surveyed in Eastern Uganda. The result shows that the number of indigenous tree species in coffee farms was lower than that of forest reserve. Similarly, tree species richness per plot, Shannon and Simpson diversity indexes of forest reserve were significantly (p<0.05) higher than that of coffee farms. However, with the inclusion of exotic tree species, coffee farms were found to be significantly higher than that of forest reserve for the above diversity indexes. On the other hand, the distribution of tree species in the coffee farms were mainly dominated by few tree species indicating the need for measures that ensure the sustainability of those less represented tree species.
Applied Journal of Environmental Engineering Science, Dec 30, 2019
The main objective of the study is to analysis sustainability of water supply and distribution sy... more The main objective of the study is to analysis sustainability of water supply and distribution system of Asossa town. While conducting this research, both primary and secondary data were collected and software such as water GEMSV8i, ArcGIS version10.4.1 and GPS Garmin72 were used. The water supply source of the study area yields 46.1 l/s but only 23.6 l/s of water used. The simulated result of extended period simulation showed that the performance of hydraulic parameters were pressure 21.05 % for pressure value <15 m, 72.8 % for pressure value 15-60 m and 6.15 % for pressure value >60 m head and the velocity of pipe flow showed that 84.86 % for velocity <0.6 m/s, 15.14 % for velocity range 0.6-2 m/s. Based on the simulated result, reliability value 0.728 and 0.151, vulnerability value 0.251 and 0.538 and resiliency value 0.322 and 0.1 were obtained for both pressure and velocity, respectively. The overall sustainability index was 0.375 but 0.19 for velocity and 0.559 for pressure. Therefore, sustainability of existing water supply and distribution system of Assosa town is not sustainable. It is mandatory to redesign the Assosa town water supply and distribution system in order to make it sustainable.
International Journal of Analytical Chemistry, Sep 29, 2022
Water treatment is the primary consideration before utilizing water for di erent purposes. Surfac... more Water treatment is the primary consideration before utilizing water for di erent purposes. Surface water is highly vulnerable to pollution, either due to natural or anthropogenic processes. e main targets of this study were to investigate surface water treatment using Moringa Oleifera (MO), the electrocoagulation process (EC), and the Moringa Oleifera assisted electrocoagulation process (MOAEC). e Moringa Oleifera, EC process, and Moringa Oleifera-assisted EC process are e ective mechanisms for the removal of COD (Chemical Oxygen Demand), BOD (Biological Oxygen Demand), TDS (Total Dissolved Solids), phosphate, TSS (Total Suspended Solids), and color from surface water. Di erent operating parameters such as pH (5-11), the dosage of coagulant (0.2-0.5 g), contact time or reaction time (20-50 minutes), current (0.2-0.5 A), and settling time (5-20 minutes) were considered. e maximum removal e ciency using Moringa Oleifera and the EC process was COD (85.48%), BOD (78.50%), TDS (84.5%), phosphate (95.70%), TSS (93.90%), color (94.50%), and COD (90.50%), BOD (87%), TDS (97.50%), phosphate (89.10%), TSS (95.80%), and color (96.15%), respectively. Similarly, with the application of MOAEC, 91.47%, 89.35%, 97.0%, 90.20%, 9.10%, and 95.70% of COD, BOD, TDS, phosphate, TSS, and color were removed, respectively. e EC process and MOAEC were more e ective in the removal of COD, BOD, TDS, TSS, and color than using MO. More phosphate was removed using MO than the EC process and MOAEC. Additionally, the e ects of di erent operating parameters were studied on the removal e ciency.
In this study, the treatment of landfill leachate by sono (US) and photo (UV) based advanced oxid... more In this study, the treatment of landfill leachate by sono (US) and photo (UV) based advanced oxidation processes (AOPs) was investigated in terms of % color and COD removal, together with electrical energy per order. Experimental results showed that, the hybrid sono-photo-Fenton (US/UV/Fe 2+ / H 2 O 2) process has shown that higher removal of color (100%) and COD (96%) with required of low electrical energy per order (0.71 kWh/m 3) than the other processes. The influence of various experimental parameters such as H 2 O 2 and Fe 2+ concentration, COD concentration, solution pH, sonication (US) and photo (UV) power on the % color and COD removal with electrical energy per order has been studied to find out the optimum conditions leading to maximum % removal efficiency of hybrid US/UV/Fe 2+ /H 2 O 2 process. The best results of US/UV/Fe 2+ /H 2 O 2 process of landfill leachate have been obtained using 80 mM of H 2 O 2 , 40 mM of Fe 2+ , pH of 3, COD concentration of 2,000 ppm, sonication power of 100 W and UV power of 32 W and after 3 h of reaction time. The synergy index between sonication (US) and photo-Fenton (UV/Fe 2+ /H 2 O 2) process has been studied and critically reported. Therefore, the combination of US and UV based AOPs has been proved to be efficient treatment techniques for removal of pollutant from industrial effluent and wastewater.
In order to lower the high prices of individual feedstock, extend the life of a more limited feed... more In order to lower the high prices of individual feedstock, extend the life of a more limited feedstock and to improve the fuel properties of biodiesel it imperative to optimize process parameters for biodiesel derived from mixed feedstocks. Samples of castor seeds were collected from Jimma zone, southwest Ethiopia while sample of wet microalgal biomass was obtained from wastewater stabilization ponds using a 60 µm filter screen. The castor seeds and microalgal biomass were sun-dried before further dried in an oven and ground to pastes. Oils were extracted from dry and milled castor seeds and microalgae pastes with a Soxhlet apparatus using methanol. The extracted oil was purified, mixed in 1:1 ratio and characterized before converted to biodiesel. A transesterification process designed using RSM based on CCD experimental design was used to optimize the production process parameters using alkaline catalyst. The Design Expert® 12 software was used to analysis the experimental results. The effects of catalyst concentration, ethanol to oil molar ratio and reaction temperature on the yield of biodiesel were investigated using the experimental results. The optimum conditions for biodiesel production from mixed oil were a catalyst concentration of 1.23%, alcohol to oil molar ratio of 5.94:1 and reaction temperature of 51.30 0 C. The yield of biodiesel under these conditions was 93.88%. Experiment was conducted under the specified optimum conditions to validate the result predicted. The yield of biodiesel from the experiment was 93.36% which is very close to the value predicted by the model. The fatty acid composition of the biodiesel was analyzed using GC. The fuel properties of biodiesel were determined according to procedures outlined in ASTM D6751 and EN 14214 standards. The physicochemical properties fulfill both standards.
Stringent discharge limits, high costs, and low removal efficiency of the conventional treatment ... more Stringent discharge limits, high costs, and low removal efficiency of the conventional treatment methods are facing challenges to handle industrial effluents containing heavy metals. The objective of this study was to use a recoverable magnetic zeolite to remove Cr(VI) from aqueous solution. The study investigated the application of nanotechnology to improve surface properties, recoverability, and adsorptive capacity of natural zeolite and the CCD-RSM-based optimization of adsorption process variables. Natural zeolites coated with various fractions of magnetic nanoparticles (25%, 33.33%, 50%, and 75%) were investigated for surface characters, adsorption capacity, removal efficiency, and recoverability. Natural zeolite coated with 33.33% (MZ33) was found a better adsorbent in terms of surface characters, adsorption capacity, and removal efficiency. Thirty batch adsorption experiments designed with CCD were carried out in order to optimize adsorption process variables using response surface methodology (RSM). It was found that adsorbent dose = 2 g/L, contact time = 75 min, initial CrðVIÞ concentration = 10 mg/L, and solution pH = 1:5 were the optimum conditions to achieve 93.57% Cr(VI) removal, which is very close to the experimental result of 94.88%. The adsorption isotherm determined from the operating parameters revealed that experimental data fit to the Langmuir isotherm model with R 2 = 0:9966 and maximum adsorption capacity = 43:933 mg/g. This proved that the adsorption of Cr(VI) on magnetic zeolite involved monolayer adsorption on the active sites. The separation factor, R L , value lies between 0 and 1 indicating that adsorption of Cr(VI) on the magnetic zeolite is favorable. The adsorption kinetics study follows pseudo-first order in the removal of Cr(VI). FTIR analysis of magnetic zeolite revealed the presence of numerous functional groups participating in Cr(VI) adsorption. The current study confirmed that magnetic zeolite is a cost-effective and favorable material for the removal of Cr(VI) from aqueous solution.
Applied and Environmental Soil Science, Jul 6, 2022
Plant growth-promoting rhizobacteria (PGPR) are an important bacterial resource as biofertilizers... more Plant growth-promoting rhizobacteria (PGPR) are an important bacterial resource as biofertilizers, which can promote plant growth and increase crop yields. In this study, isolation, characterization, and its e ect on plant promotion were assessed by isolating PGPR using soil samples collected from Jimma, Ethiopia. Out of 10 isolates, three of them (JEC3, JEC4, and JEC7) exhibited PSB traits in Pikovskaya media by solubilizing phosphate and producing IAA. Of the three isolates, JEC4 recorded the maximum phosphate solubilization index (4.98), soluble phosphate (283 μg/ml), and IAA production (10.21 μg/ml). e ndings of the isolates' morphological and biochemical tests showed that JEC3, JEC4, and JEC7 as Bacillus sp., Pseudomonas sp., and Enterobacter sp., respectively. e optimization of phosphate solubilization was done using di erent incubation times and sources of carbon and nitrogen. Furthermore, the isolate (JEC4) was tested for plant growth-promoting (PGP) activities and indicated the production of ammonia, hydrogen cyanide, and siderophore. JEC4 isolate showed a signi cant increase in sideways (%) seed germination, root and shoot length, fresh and dry weight of root, and shoot of maize in eld experiments than the untreated ones. e results indicate that the JEC4 isolate can be developed as a biological fertilizer for promoting crop productivity and ecosystem dynamics.
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