Emmanuel A Kamba | Federal University, Wukari, Taraba State (original) (raw)
Papers by Emmanuel A Kamba
The rate of CO2 production obtained from the photodecomposition of acetone with different loading... more The rate of CO2 production obtained from the photodecomposition of acetone with different loadings of TiO2 as a photocatalyst is remarkable. This study aims to develop a flow-type photo reactor with excellent contact between all the reacting species. To achieve total mineralization with minimal waste, the flow rate of gases was controlled. During this investigation, the acetone was fed at the rate of 2.8 mmol h-1 and the air flow rate was maintained at 4.3 Lh-1. The reaction was carried out at near room temperature as the cold cathode lamps increased temperature very slowly to 63 ᵒ C. No CO2 was produced either without light or catalyst indicating a photocatalytic reaction. There was a proportional increase in the production of CO2 with an increase in TiO2 loading. A maximum rate of 5.75 ± 0.07 mMh-1 for CO2 production was achieved with a catalyst loading of 5 mg/gbeads. Increasing the catalyst loading above 5 mg/g showed a decrease in CO2 production rate which can be attributed to reduced contact between light and catalyst. This technique used here can be adopted for the decomposition of various Volatile Organic Compounds (VOCs). HIGHLIGHTS A new catalyst immobilization technique was investigated. A transparent glass beads were used for the reactor for excellent UV exposure. No CO2 was observed in the absence of light, catalyst or oxidant. The formation of CO2 from adsorbed carbonaceous is possible.
The photo activities of some photo-catalysts including TiO 2 , Bi 2 WO 6 and Bi 2 WO 6-TiO 2 (in ... more The photo activities of some photo-catalysts including TiO 2 , Bi 2 WO 6 and Bi 2 WO 6-TiO 2 (in various mixing ratios) were evaluated for photo-epoxidation of propylene. The photocatalytic epoxidation reaction was performed in gas-phase under atmospheric pressure. Typical reaction mixture of C 3 H 6 :O 2 :N 2 corresponding to the ratio 1:1:18, afforded PO (PO) in addition to other products such as acetone, acetaldehyde and propanal as observed by the FTIR-GCMS tandem analysis. It was established from the results that Bi 2 WO 6-TiO 2 photo-catalysts were more preferable for selectivity of PO peaking at 49%. The highest formation rate of PO achieved was 111µmol g cat-1 h-1 over 12mol% Bi 2 WO 6-TiO 2 ratio in a typical flow reaction for 1h at 345 K under UVA illumination. Under this condition the selectivity of products was also observed to be very stable. Further study on the effect of light intensity revealed that increasing the light intensity from 0.1 to 0.3mWcm-2 significantly increased the selectivity of PO by 5%. Higher intensity depreciated the PO selectivity. In order to study the effect of temperature on the photocatalytic epoxidation reaction, a systematic approach was followed. As raising the reaction temperature influences the distribution of products significantly, a temperature range of 335-355 K was used in the optimised reaction condition. At 355 K, it was observed that the formation of propanal was favoured which was attributed to its inhibition to be transformed into propionic acid. However, raising the reaction temperature was observed to affect the rate of reaction in two ways: first, the adsorption of PR on to the photo-catalyst which causes a decrease in the reaction efficiency was reduced and secondly, the desorption of products of reaction which in turn reveals more active sites, was improved.
EMBARGOED - expected end date 16.12.202
International journal of materials and chemistry, 2013
The ratio of emu lsify ing agents used to achieve stability is very important. In th is study eff... more The ratio of emu lsify ing agents used to achieve stability is very important. In th is study effect of surfactant HLB and concentration on the emulsion stability were investigated. The time required for the two liquids to separate, creaming volume and microscopic observation were used to assess the emulsion stability. Emu lsifiers used in this study are based on their chemical structures and include synthetic, natural and finely dispersed solid particles emulsifiers. It was observed that the optimal surfactant concentration for oil/ water emulsion long-term stability were 20% wt/vol. soap in the oil phase and 0.1% wt/vol. detergent in the continuous phase. Higher concentration of soap had a destructive effect on oil/water emu lsion stability wh ich correlated with the observation that interfacial film strength at the oil/water interface decreases as the detergent concentration increases. Methanol added to the inner aqueous phase exerted an osmotic pressure that caused diffusion of o il into aqueous phase and increased oil/water emulsion v iscosity through an increase in the volume fraction of the primary oil/water emu lsion. These types of viscosity increase impose a destabilization effect because of the likelihood of rupture of the outer and continuous phase droplets.
chemistry and materials research, 2014
The application of Modified Melon Seed Husk (MMH) an agricultural waste in the remediation of wat... more The application of Modified Melon Seed Husk (MMH) an agricultural waste in the remediation of water contaminated with lead ions was investigated in the present study. Modification was done by soaking the melon seed husk in 0.5M NaOH solution. Batch kinetic and isotherm studies was performed to understand the ability of the adsorbents. Effect of some process variables were assessed viz: pH, initial metal ion concentration and sorbent dosage on the sorption process. The equilibrium sorption isotherm was studied using the Freundlich and Langmuir isotherm models. The results obtained showed that the process of the sorption fitted better with the Freundlich isotherm, implying that the sorption occurred on a heterogeneous surface of the MMH. The monolayer adsorptioncapacity determined from the Langmuir adsorption equation was found to be 52.08 mg/g which competes favourable with some other biosorbents. Data obtained from the kinetics of the sorption process via initial metal ion concentration were analyzed using pseudo second order, the pseudo first order model and intraparticle diffusion model. The sorption process obeyed the pseudo second order kinetic model better than the pseudo first order kinetic model, thus suggesting the role of chemisorption in the mechanisms of the sorption. The intraparticle diffusion model showed that intraparticle diffusion is not the singular rate limiting step in the sorption process. The kinetic parameters suggest that adsorption of lead ions by MMH was favourable. Overall, the present findings suggest that MMH, an environmentally friendly, efficient and low-cost biosorbent is useful for the removal of Pb 2+ from aqueous media.
Journal Of Chemical Society Of Nigeria, Feb 14, 2017
Phosphorus removal from aquaculture wastewater is essential to protect the receiving waters from ... more Phosphorus removal from aquaculture wastewater is essential to protect the receiving waters from eutrophication. This study evaluated the potential of African Land snail shell (GS), a low cost biogenic waste, for phosphorus removal from a simulated aquaculture wastewater in a batch process. The kinetic analysis of the P sorption by the GS showed that pseudo-second order kinetic equation adequately described the process, thus confirming chemisorption as the underlying mechanism of the P removal process by the GS. The fitting of the data obtained from the equilibrium isotherm analysis gave a value of 3.077mg/g for the Langmuir monolayer sorption capacity and Langmuir equilibrium isotherm equation showed the best fitting (r 2 = 0.999). Evaluation of the effects of process variables on the P-removal process indicated that solution pH and organic load influenced the magnitude of P removed from solution.
European of agriculture and food sciences, Jan 17, 2023
The majority of the world's population relies on livestock as source of protein whereas the succe... more The majority of the world's population relies on livestock as source of protein whereas the success of livestock production is reliant on availability of quality feeds which has been challenged by competition impose by geometric growth in human population. This study assessed the effect of molasses and urea treatment on the physical quality, proximate and amino acid composition of guinea corn silage as a means to augment protein content in guinea corn silage feed stocks. Guinea corn stalks samples collected randomly on farmlands around Federal University Wukari, Nigeria. After pulverization was divided into two portions and one portion subjected to molasses and urea treatment while the other served as control. Effect of treatment was assessed by estimating and comparing the physical quality, proximate and amino acid composition of the treated and untreated sample using standard methods. The result showed that the mean pH value became more acidic after treatment from 6.12 to 5.24. While the moisture, lipid and crude protein content were significantly increased due to treatment (P <0.05). There was also a significant elevation in amino acid content due to urea and molasses treatment in 14 out of the 18 amino acids determined at 95% confidence limit (P<0.05). And the total amino acid content of the silage sample was improved from 43.80 g/100g to 62.27 g/100g. The nature of amino acids in the treated silage (test sample) were in the order of prevalence total amino acid with acidic side chain (TAAA)>total amino acid with basic side chain (TBAA)>total aromatic amino acid (TArAA)>total sulphur containing amino acid (TSAA). The most concentrated amino acid was glutamic acid, an important amino acid responsible in building the immune system.
Water is a valuable resource and a primary constituent of the ecosystem, specifically in the form... more Water is a valuable resource and a primary constituent of the ecosystem, specifically in the form of rivers, lakes, glaciers, rainwater, groundwater etc. Besides the desire of water for drinking, water resource is critical in diverse sectors of the economy ranging from agriculture, animal production, forestry, commerce, hydropower generation, fisheries, and different innovative activities. The availability of potable water is becoming scarce due to the ever-growing population, industrialization, and urbanization. The quality of any given water may be assessed through the usage of physical, chemical, and biological parameters. Their values are dangerous for human fitness if they are above the restricted requirement set by standard organizations (WHO, 2012; USEPA, 2013). Recently, the suitability of water resources for usage has been defined in terms of the "water quality index" (WQI) to aid in formulating and modifying policies by various environmental monitoring agencies. The introduction of WQI has become more beneficial than using individual water quality parameters to explain water quality (Bharti and Katyal, 2011; Uddin et al., 2021). The goal of WQI is to describe water fitness using a single numerical value, thereby decreasing the quantity of individual parameters to be employed when defining water quality and easing the interpretation of data (Singh et al., 2013). This approach also reduces the bulk of information from the individual water quality variables into a single data to express water quality status of specific areas based on the types of quality parameters peculiar to that locality compared with established standards particular to the region. WQI are efficiently employed to monitor annual cycles, spatial and temporal changes in water quality and variations in water composition even at low concentrations (Uddin et al., 2021). Apart from the challenges of water availability, continuous discharge of sewage and pollutants into available water has reduced the amount of usable water as most surface and groundwater are being labelled
The extraction of chitin from Bargi fish (Heterotis Miloticus) scale used in removing Cr (VI) hav... more The extraction of chitin from Bargi fish (Heterotis Miloticus) scale used in removing Cr (VI) have been evaluated using chemical and physical methods. The physical parameters investigated include: Equilibrium Contact Time (ECT), pH Adsorption Isotherm (AI) Langmuir isotherm (LI), Freundlich Isotherm (FI) and Thermodynamic Studies (TS). The chemical parameter used is Initial Metal Concentration (IMC). The physical parameters show the following: increasing the contact time increased the adsorption of the Cr (VI) ion and remained constant after an equilibration time of 60 min. The uptake of Cr (VI) ion by chitin was due to the presence of crystalline network, acetamide groups instead of hydroxyl groups and little amino groups which prevent further adsorption of Cr (VI). The adsorption of Cr (VI) increased with increase in pH from 2 to 6. The adsorption isotherm showed a sort of plateau, hence there is a formation of a complete monolayer of the metal ion covering the adsorbent surface. The thermodynamic study revealed that increasing the temperature decreases the adsorption capacity. The chemical parameter showed that when the concentration of the initial metal ion was increased, there was an increase in the amount of metal ion removed from the solution. Therefore the process is temperature dependent, pH dependent and maximum adsorption capacity was found at pH 6-8.
chemistry and materials research, 2014
The potential utilization of Brewer's Spent Grain (BSG) was investigated in the removal of Cadmiu... more The potential utilization of Brewer's Spent Grain (BSG) was investigated in the removal of Cadmium and Zinc from aqueous system. Batch sorption process assessment of the effects of process variables showed that pH, initial metal ion concentration and dosage amount affect the sorption and uptake of Cd and Zn ions by BSG. Analysis of the sorption process using different kinetic models showed that the pseudo first order kinetic models gave poor descriptions of the process for Zn was r 2 = 0.5268 but a good one for Cd at r 2 = 0.9618 while the pseudo second order kinetic model gave a good description of the process for both metal ions (r 2 >0.98). The Pseudo second order rate constant obtained for Zn (1.0812mgg-1 min-1) is than that for Cd (0.17mgg-1 min-1).Equilibrium isotherm analysis of the sorption process data showed that the Langmuir isotherm gave a better description of the process than the Freundlich for Cd while both Freundlich and Langmuir fitted very well for Zn sorption by BSG. The results of the studies indicate that the metal ions were favourably adsorbed onto the adsorbent with a removal efficiency of 94.46% for Zn and 77.81% for Cd.
American Journal of Electrical Power and Energy Systems, 2013
Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and c... more Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and capacitors, known to reduce the risk of fire hazards due to their high chemical stability and low flammability turned out to be environmentally hazardous. In this research, different techniques used to analyses Polychlorinated biphenyls (PCBs) in transformer oil including their qualification and identification processes have been outlined. 12 samples of transformer oils collected from various transformers from Kebbi state, Nigeria were investigated. Solid Phase Extraction (SPE) method was used to treat the oil samples and extracts were analyzed on Gas Chromatography with Electron Capture Detection (GC/ECD). No detectable PCBs were observed. To check the efficiency the SPE tubes, oil sample A10 was spiked with Mix 525 of PCB standard and treated. A full recovery of all the PCBs of Mix 525 was made even at a level as low as 50ng/ul with GC/MS. The results obtained in this study confirm that transformer oil from Kebbi state is well within the safe level of PCBs in accordance with EPA PCB Regulatory limited.
American journal of electrical power and energy systems, 2013
Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and c... more Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and capacitors, known to reduce the risk of fire hazards due to their high chemical stability and low flammability turned out to be environmentally hazardous. In this research, different techniques used to analyses Polychlorinated biphenyls (PCBs) in transformer oil including their qualification and identification processes have been outlined. 12 samples of transformer oils collected from various transformers from Kebbi state, Nigeria were investigated. Solid Phase Extraction (SPE) method was used to treat the oil samples and extracts were analyzed on Gas Chromatography with Electron Capture Detection (GC/ECD). No detectable PCBs were observed. To check the efficiency the SPE tubes, oil sample A10 was spiked with Mix 525 of PCB standard and treated. A full recovery of all the PCBs of Mix 525 was made even at a level as low as 50ng/ul with GC/MS. The results obtained in this study confirm that transformer oil from Kebbi state is well within the safe level of PCBs in accordance with EPA PCB Regulatory limited.
The rate of CO2 production obtained from the photodecomposition of acetone with different loading... more The rate of CO2 production obtained from the photodecomposition of acetone with different loadings of TiO2 as a photocatalyst is remarkable. This study aims to develop a flow-type photo reactor with excellent contact between all the reacting species. To achieve total mineralization with minimal waste, the flow rate of gases was controlled. During this investigation, the acetone was fed at the rate of 2.8 mmol h-1 and the air flow rate was maintained at 4.3 Lh-1. The reaction was carried out at near room temperature as the cold cathode lamps increased temperature very slowly to 63 ᵒ C. No CO2 was produced either without light or catalyst indicating a photocatalytic reaction. There was a proportional increase in the production of CO2 with an increase in TiO2 loading. A maximum rate of 5.75 ± 0.07 mMh-1 for CO2 production was achieved with a catalyst loading of 5 mg/gbeads. Increasing the catalyst loading above 5 mg/g showed a decrease in CO2 production rate which can be attributed to reduced contact between light and catalyst. This technique used here can be adopted for the decomposition of various Volatile Organic Compounds (VOCs). HIGHLIGHTS A new catalyst immobilization technique was investigated. A transparent glass beads were used for the reactor for excellent UV exposure. No CO2 was observed in the absence of light, catalyst or oxidant. The formation of CO2 from adsorbed carbonaceous is possible.
The photo activities of some photo-catalysts including TiO 2 , Bi 2 WO 6 and Bi 2 WO 6-TiO 2 (in ... more The photo activities of some photo-catalysts including TiO 2 , Bi 2 WO 6 and Bi 2 WO 6-TiO 2 (in various mixing ratios) were evaluated for photo-epoxidation of propylene. The photocatalytic epoxidation reaction was performed in gas-phase under atmospheric pressure. Typical reaction mixture of C 3 H 6 :O 2 :N 2 corresponding to the ratio 1:1:18, afforded PO (PO) in addition to other products such as acetone, acetaldehyde and propanal as observed by the FTIR-GCMS tandem analysis. It was established from the results that Bi 2 WO 6-TiO 2 photo-catalysts were more preferable for selectivity of PO peaking at 49%. The highest formation rate of PO achieved was 111µmol g cat-1 h-1 over 12mol% Bi 2 WO 6-TiO 2 ratio in a typical flow reaction for 1h at 345 K under UVA illumination. Under this condition the selectivity of products was also observed to be very stable. Further study on the effect of light intensity revealed that increasing the light intensity from 0.1 to 0.3mWcm-2 significantly increased the selectivity of PO by 5%. Higher intensity depreciated the PO selectivity. In order to study the effect of temperature on the photocatalytic epoxidation reaction, a systematic approach was followed. As raising the reaction temperature influences the distribution of products significantly, a temperature range of 335-355 K was used in the optimised reaction condition. At 355 K, it was observed that the formation of propanal was favoured which was attributed to its inhibition to be transformed into propionic acid. However, raising the reaction temperature was observed to affect the rate of reaction in two ways: first, the adsorption of PR on to the photo-catalyst which causes a decrease in the reaction efficiency was reduced and secondly, the desorption of products of reaction which in turn reveals more active sites, was improved.
EMBARGOED - expected end date 16.12.202
International journal of materials and chemistry, 2013
The ratio of emu lsify ing agents used to achieve stability is very important. In th is study eff... more The ratio of emu lsify ing agents used to achieve stability is very important. In th is study effect of surfactant HLB and concentration on the emulsion stability were investigated. The time required for the two liquids to separate, creaming volume and microscopic observation were used to assess the emulsion stability. Emu lsifiers used in this study are based on their chemical structures and include synthetic, natural and finely dispersed solid particles emulsifiers. It was observed that the optimal surfactant concentration for oil/ water emulsion long-term stability were 20% wt/vol. soap in the oil phase and 0.1% wt/vol. detergent in the continuous phase. Higher concentration of soap had a destructive effect on oil/water emu lsion stability wh ich correlated with the observation that interfacial film strength at the oil/water interface decreases as the detergent concentration increases. Methanol added to the inner aqueous phase exerted an osmotic pressure that caused diffusion of o il into aqueous phase and increased oil/water emulsion v iscosity through an increase in the volume fraction of the primary oil/water emu lsion. These types of viscosity increase impose a destabilization effect because of the likelihood of rupture of the outer and continuous phase droplets.
chemistry and materials research, 2014
The application of Modified Melon Seed Husk (MMH) an agricultural waste in the remediation of wat... more The application of Modified Melon Seed Husk (MMH) an agricultural waste in the remediation of water contaminated with lead ions was investigated in the present study. Modification was done by soaking the melon seed husk in 0.5M NaOH solution. Batch kinetic and isotherm studies was performed to understand the ability of the adsorbents. Effect of some process variables were assessed viz: pH, initial metal ion concentration and sorbent dosage on the sorption process. The equilibrium sorption isotherm was studied using the Freundlich and Langmuir isotherm models. The results obtained showed that the process of the sorption fitted better with the Freundlich isotherm, implying that the sorption occurred on a heterogeneous surface of the MMH. The monolayer adsorptioncapacity determined from the Langmuir adsorption equation was found to be 52.08 mg/g which competes favourable with some other biosorbents. Data obtained from the kinetics of the sorption process via initial metal ion concentration were analyzed using pseudo second order, the pseudo first order model and intraparticle diffusion model. The sorption process obeyed the pseudo second order kinetic model better than the pseudo first order kinetic model, thus suggesting the role of chemisorption in the mechanisms of the sorption. The intraparticle diffusion model showed that intraparticle diffusion is not the singular rate limiting step in the sorption process. The kinetic parameters suggest that adsorption of lead ions by MMH was favourable. Overall, the present findings suggest that MMH, an environmentally friendly, efficient and low-cost biosorbent is useful for the removal of Pb 2+ from aqueous media.
Journal Of Chemical Society Of Nigeria, Feb 14, 2017
Phosphorus removal from aquaculture wastewater is essential to protect the receiving waters from ... more Phosphorus removal from aquaculture wastewater is essential to protect the receiving waters from eutrophication. This study evaluated the potential of African Land snail shell (GS), a low cost biogenic waste, for phosphorus removal from a simulated aquaculture wastewater in a batch process. The kinetic analysis of the P sorption by the GS showed that pseudo-second order kinetic equation adequately described the process, thus confirming chemisorption as the underlying mechanism of the P removal process by the GS. The fitting of the data obtained from the equilibrium isotherm analysis gave a value of 3.077mg/g for the Langmuir monolayer sorption capacity and Langmuir equilibrium isotherm equation showed the best fitting (r 2 = 0.999). Evaluation of the effects of process variables on the P-removal process indicated that solution pH and organic load influenced the magnitude of P removed from solution.
European of agriculture and food sciences, Jan 17, 2023
The majority of the world's population relies on livestock as source of protein whereas the succe... more The majority of the world's population relies on livestock as source of protein whereas the success of livestock production is reliant on availability of quality feeds which has been challenged by competition impose by geometric growth in human population. This study assessed the effect of molasses and urea treatment on the physical quality, proximate and amino acid composition of guinea corn silage as a means to augment protein content in guinea corn silage feed stocks. Guinea corn stalks samples collected randomly on farmlands around Federal University Wukari, Nigeria. After pulverization was divided into two portions and one portion subjected to molasses and urea treatment while the other served as control. Effect of treatment was assessed by estimating and comparing the physical quality, proximate and amino acid composition of the treated and untreated sample using standard methods. The result showed that the mean pH value became more acidic after treatment from 6.12 to 5.24. While the moisture, lipid and crude protein content were significantly increased due to treatment (P <0.05). There was also a significant elevation in amino acid content due to urea and molasses treatment in 14 out of the 18 amino acids determined at 95% confidence limit (P<0.05). And the total amino acid content of the silage sample was improved from 43.80 g/100g to 62.27 g/100g. The nature of amino acids in the treated silage (test sample) were in the order of prevalence total amino acid with acidic side chain (TAAA)>total amino acid with basic side chain (TBAA)>total aromatic amino acid (TArAA)>total sulphur containing amino acid (TSAA). The most concentrated amino acid was glutamic acid, an important amino acid responsible in building the immune system.
Water is a valuable resource and a primary constituent of the ecosystem, specifically in the form... more Water is a valuable resource and a primary constituent of the ecosystem, specifically in the form of rivers, lakes, glaciers, rainwater, groundwater etc. Besides the desire of water for drinking, water resource is critical in diverse sectors of the economy ranging from agriculture, animal production, forestry, commerce, hydropower generation, fisheries, and different innovative activities. The availability of potable water is becoming scarce due to the ever-growing population, industrialization, and urbanization. The quality of any given water may be assessed through the usage of physical, chemical, and biological parameters. Their values are dangerous for human fitness if they are above the restricted requirement set by standard organizations (WHO, 2012; USEPA, 2013). Recently, the suitability of water resources for usage has been defined in terms of the "water quality index" (WQI) to aid in formulating and modifying policies by various environmental monitoring agencies. The introduction of WQI has become more beneficial than using individual water quality parameters to explain water quality (Bharti and Katyal, 2011; Uddin et al., 2021). The goal of WQI is to describe water fitness using a single numerical value, thereby decreasing the quantity of individual parameters to be employed when defining water quality and easing the interpretation of data (Singh et al., 2013). This approach also reduces the bulk of information from the individual water quality variables into a single data to express water quality status of specific areas based on the types of quality parameters peculiar to that locality compared with established standards particular to the region. WQI are efficiently employed to monitor annual cycles, spatial and temporal changes in water quality and variations in water composition even at low concentrations (Uddin et al., 2021). Apart from the challenges of water availability, continuous discharge of sewage and pollutants into available water has reduced the amount of usable water as most surface and groundwater are being labelled
The extraction of chitin from Bargi fish (Heterotis Miloticus) scale used in removing Cr (VI) hav... more The extraction of chitin from Bargi fish (Heterotis Miloticus) scale used in removing Cr (VI) have been evaluated using chemical and physical methods. The physical parameters investigated include: Equilibrium Contact Time (ECT), pH Adsorption Isotherm (AI) Langmuir isotherm (LI), Freundlich Isotherm (FI) and Thermodynamic Studies (TS). The chemical parameter used is Initial Metal Concentration (IMC). The physical parameters show the following: increasing the contact time increased the adsorption of the Cr (VI) ion and remained constant after an equilibration time of 60 min. The uptake of Cr (VI) ion by chitin was due to the presence of crystalline network, acetamide groups instead of hydroxyl groups and little amino groups which prevent further adsorption of Cr (VI). The adsorption of Cr (VI) increased with increase in pH from 2 to 6. The adsorption isotherm showed a sort of plateau, hence there is a formation of a complete monolayer of the metal ion covering the adsorbent surface. The thermodynamic study revealed that increasing the temperature decreases the adsorption capacity. The chemical parameter showed that when the concentration of the initial metal ion was increased, there was an increase in the amount of metal ion removed from the solution. Therefore the process is temperature dependent, pH dependent and maximum adsorption capacity was found at pH 6-8.
chemistry and materials research, 2014
The potential utilization of Brewer's Spent Grain (BSG) was investigated in the removal of Cadmiu... more The potential utilization of Brewer's Spent Grain (BSG) was investigated in the removal of Cadmium and Zinc from aqueous system. Batch sorption process assessment of the effects of process variables showed that pH, initial metal ion concentration and dosage amount affect the sorption and uptake of Cd and Zn ions by BSG. Analysis of the sorption process using different kinetic models showed that the pseudo first order kinetic models gave poor descriptions of the process for Zn was r 2 = 0.5268 but a good one for Cd at r 2 = 0.9618 while the pseudo second order kinetic model gave a good description of the process for both metal ions (r 2 >0.98). The Pseudo second order rate constant obtained for Zn (1.0812mgg-1 min-1) is than that for Cd (0.17mgg-1 min-1).Equilibrium isotherm analysis of the sorption process data showed that the Langmuir isotherm gave a better description of the process than the Freundlich for Cd while both Freundlich and Langmuir fitted very well for Zn sorption by BSG. The results of the studies indicate that the metal ions were favourably adsorbed onto the adsorbent with a removal efficiency of 94.46% for Zn and 77.81% for Cd.
American Journal of Electrical Power and Energy Systems, 2013
Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and c... more Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and capacitors, known to reduce the risk of fire hazards due to their high chemical stability and low flammability turned out to be environmentally hazardous. In this research, different techniques used to analyses Polychlorinated biphenyls (PCBs) in transformer oil including their qualification and identification processes have been outlined. 12 samples of transformer oils collected from various transformers from Kebbi state, Nigeria were investigated. Solid Phase Extraction (SPE) method was used to treat the oil samples and extracts were analyzed on Gas Chromatography with Electron Capture Detection (GC/ECD). No detectable PCBs were observed. To check the efficiency the SPE tubes, oil sample A10 was spiked with Mix 525 of PCB standard and treated. A full recovery of all the PCBs of Mix 525 was made even at a level as low as 50ng/ul with GC/MS. The results obtained in this study confirm that transformer oil from Kebbi state is well within the safe level of PCBs in accordance with EPA PCB Regulatory limited.
American journal of electrical power and energy systems, 2013
Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and c... more Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and capacitors, known to reduce the risk of fire hazards due to their high chemical stability and low flammability turned out to be environmentally hazardous. In this research, different techniques used to analyses Polychlorinated biphenyls (PCBs) in transformer oil including their qualification and identification processes have been outlined. 12 samples of transformer oils collected from various transformers from Kebbi state, Nigeria were investigated. Solid Phase Extraction (SPE) method was used to treat the oil samples and extracts were analyzed on Gas Chromatography with Electron Capture Detection (GC/ECD). No detectable PCBs were observed. To check the efficiency the SPE tubes, oil sample A10 was spiked with Mix 525 of PCB standard and treated. A full recovery of all the PCBs of Mix 525 was made even at a level as low as 50ng/ul with GC/MS. The results obtained in this study confirm that transformer oil from Kebbi state is well within the safe level of PCBs in accordance with EPA PCB Regulatory limited.