Shea fruit shells being an agricultural waste material was utilized to test its novelty as an ine... more Shea fruit shells being an agricultural waste material was utilized to test its novelty as an inexpensive biosorbent for the elimination of Cd(II) from synthetic wastewater using the batch method. A batch study was employed to probe the impact of pH of the solution, contact time, temperature and initial concentration on the depollution of Cd(II) ions using unmodified Shea fruit shells biomass. The decontamination of Cd(II) by the unmodified Shea fruit shells biomass was found to be dependent on these adsorption parameters. The equilibrium data best represented Freundlich isotherm by a correlation coefficient (R2) of 0.9691. The kinetic models analyzed suggest pseudo-second-order ($${R}^{2} = 0.9515$$ R 2 = 0.9515 ) as the best fit model signifying that the removal of Cd(II) ions was on account of chemisorption. The positive values of the thermodynamic parameters, ΔH° and ΔS° reveal endothermic and increase of disorder of the process while the negative charge of ΔG° shows spontaneity...
The review revealed that both natural and engineered adsorbents could remove heavy metals from mu... more The review revealed that both natural and engineered adsorbents could remove heavy metals from multicomponent systems. However, the competitive effects among heavy metal ions in the multicomponent system influences their individual uptake capacity.
The mineral sector, especially its small-scale subsector, has become significant in the emerging ... more The mineral sector, especially its small-scale subsector, has become significant in the emerging economies of the Global South. Tanzania is the focus of this policy exposition paper because, aside from Ghana and South Africa, Tanzania is ranked 4th in Africa in terms of its mineral deposits and small-scale mining activities. The focus is also on artisanal and small-scale mining (ASM) because ASM operations have significantly increased in recent times across this mineral-rich country of East Africa. This is done against a negative backdrop-labelling of ASM as unsustainable, envi- ronmentally unfriendly, inefficient, and illegal. Tanzania has made some progress to respond to some of the challenges in the mining sector to improve the micro and macroeconomics of the country. Some areas remain challenging including the lack of proper environmental health ed- ucation for the ASM miners; the lack of clear national-level policies to guide health-related matters in the ASM subsector, and the small capital investment of the ASM subsector to sup- port healthy mining practices. The details related to the persistence of these challenges are not well known, particularly those that pertain to policymaking. This article attempts to evaluate the policy environment of the ASM subsector in Tanzania and propose appropriate actions for the future of mineral resource policymaking in Tanzania.
Biosorbents are found promising for the detoxification of water contaminants. This comprehensive ... more Biosorbents are found promising for the detoxification of water contaminants. This comprehensive review indicates that these biosorbents are more efficient and cost-effective for the purification of water and wastewater containing lead(ii) ions.
The existence of hazardous heavy metals in aquatic settings causes health risks to humans, prompt... more The existence of hazardous heavy metals in aquatic settings causes health risks to humans, prompting researchers to devise effective methods for removing these pollutants from drinking water and wastewater. To obtain optimum removal efficiencies and sorption capacities of the contaminants on the sorbent materials, it is normally necessary to optimize the purification technology to attain the optimum value of the independent process variables. This review discusses the most current advancements in using various adsorbents for heavy metal remediation, as well as the modeling and optimization of the adsorption process independent factors by response surface methodology. The remarkable efficiency of the response surface methodology for the extraction of the various heavy metal ions from aqueous systems by various types of adsorbents is confirmed in this critical review. For the first time, this review also identifies several gaps in the optimization of adsorption process factors that need to be addressed. The comprehensive analysis and conclusions in this review should also be useful to industry players, engineers, environmentalists, scientists, and other motivated researchers interested in the use of the various adsorbents and optimization methods or tools in environmental pollution cleanup.
Groundnut shells, a low-cost agricultural waste material were used without any physical or chemic... more Groundnut shells, a low-cost agricultural waste material were used without any physical or chemical modification as an alternative and cheap adsorbent for the removal of Cr (VI) ion from aqueous solution. The aqueous solutions containing different concentrations of Cr (VI) were treated with fixed doses of groundnut shells powder for an equilibrium time of 90 min. The determination of Cr (VI) concentration in the sample solutions was carried out using UV-Vis spectrophotometer by the diphenylcarbazide indicator method. The equilibrium isotherm studies showed that the groundnut shell has a significant capacity for the adsorption of Cr (VI) from aqueous solutions. For the various adsorption isotherm models tested, Tempkin isotherm model showed a better representation of the equilibrium data with a good correlation coefficient (R 2 ) greater than 0.99. The FT-IR results gave an indication of the possible functional groups located on the surface of the groundnut shell. These groups influe...
Potentially toxic trace elements such as lead when present in high levels in water, food and soil... more Potentially toxic trace elements such as lead when present in high levels in water, food and soil post serious human health threats all over the world. Adsorption process using different natural materials is among the most effective techniques for removing many heavy metal ions from different types of water sources. In this study, an attempt has been made to investigate the efficiency of groundnut shells for removing lead from aqueous solutions using batch mode technique. The equilibrium data was analyzed using one one-parameter, six two-parameter and two three-parameter adsorption isotherm models. The experimental data fitted well to twoparameter isotherm (Tempkin adsorption isotherm) in comparison to the other adsorption isotherm models analyzed. The correlation coefficient of Tempkin adsorption isotherm was found to be 0.9661 indicating that the groundnut shell could remove about 96.61 % of Pb (II) ions effectively from the aqueous solution.Fourier transform infrared (FT-IR) spec...
Shea fruit shells being an agricultural waste material was utilized to test its novelty as an ine... more Shea fruit shells being an agricultural waste material was utilized to test its novelty as an inexpensive biosorbent for the elimination of Cd(II) from synthetic wastewater using the batch method. A batch study was employed to probe the impact of pH of the solution, contact time, temperature and initial concentration on the depollution of Cd(II) ions using unmodified Shea fruit shells biomass. The decontamination of Cd(II) by the unmodified Shea fruit shells biomass was found to be dependent on these adsorption parameters. The equilibrium data best represented Freundlich isotherm by a correlation coefficient (R2) of 0.9691. The kinetic models analyzed suggest pseudo-second-order ($${R}^{2} = 0.9515$$ R 2 = 0.9515 ) as the best fit model signifying that the removal of Cd(II) ions was on account of chemisorption. The positive values of the thermodynamic parameters, ΔH° and ΔS° reveal endothermic and increase of disorder of the process while the negative charge of ΔG° shows spontaneity...
The review revealed that both natural and engineered adsorbents could remove heavy metals from mu... more The review revealed that both natural and engineered adsorbents could remove heavy metals from multicomponent systems. However, the competitive effects among heavy metal ions in the multicomponent system influences their individual uptake capacity.
The mineral sector, especially its small-scale subsector, has become significant in the emerging ... more The mineral sector, especially its small-scale subsector, has become significant in the emerging economies of the Global South. Tanzania is the focus of this policy exposition paper because, aside from Ghana and South Africa, Tanzania is ranked 4th in Africa in terms of its mineral deposits and small-scale mining activities. The focus is also on artisanal and small-scale mining (ASM) because ASM operations have significantly increased in recent times across this mineral-rich country of East Africa. This is done against a negative backdrop-labelling of ASM as unsustainable, envi- ronmentally unfriendly, inefficient, and illegal. Tanzania has made some progress to respond to some of the challenges in the mining sector to improve the micro and macroeconomics of the country. Some areas remain challenging including the lack of proper environmental health ed- ucation for the ASM miners; the lack of clear national-level policies to guide health-related matters in the ASM subsector, and the small capital investment of the ASM subsector to sup- port healthy mining practices. The details related to the persistence of these challenges are not well known, particularly those that pertain to policymaking. This article attempts to evaluate the policy environment of the ASM subsector in Tanzania and propose appropriate actions for the future of mineral resource policymaking in Tanzania.
Biosorbents are found promising for the detoxification of water contaminants. This comprehensive ... more Biosorbents are found promising for the detoxification of water contaminants. This comprehensive review indicates that these biosorbents are more efficient and cost-effective for the purification of water and wastewater containing lead(ii) ions.
The existence of hazardous heavy metals in aquatic settings causes health risks to humans, prompt... more The existence of hazardous heavy metals in aquatic settings causes health risks to humans, prompting researchers to devise effective methods for removing these pollutants from drinking water and wastewater. To obtain optimum removal efficiencies and sorption capacities of the contaminants on the sorbent materials, it is normally necessary to optimize the purification technology to attain the optimum value of the independent process variables. This review discusses the most current advancements in using various adsorbents for heavy metal remediation, as well as the modeling and optimization of the adsorption process independent factors by response surface methodology. The remarkable efficiency of the response surface methodology for the extraction of the various heavy metal ions from aqueous systems by various types of adsorbents is confirmed in this critical review. For the first time, this review also identifies several gaps in the optimization of adsorption process factors that need to be addressed. The comprehensive analysis and conclusions in this review should also be useful to industry players, engineers, environmentalists, scientists, and other motivated researchers interested in the use of the various adsorbents and optimization methods or tools in environmental pollution cleanup.
Groundnut shells, a low-cost agricultural waste material were used without any physical or chemic... more Groundnut shells, a low-cost agricultural waste material were used without any physical or chemical modification as an alternative and cheap adsorbent for the removal of Cr (VI) ion from aqueous solution. The aqueous solutions containing different concentrations of Cr (VI) were treated with fixed doses of groundnut shells powder for an equilibrium time of 90 min. The determination of Cr (VI) concentration in the sample solutions was carried out using UV-Vis spectrophotometer by the diphenylcarbazide indicator method. The equilibrium isotherm studies showed that the groundnut shell has a significant capacity for the adsorption of Cr (VI) from aqueous solutions. For the various adsorption isotherm models tested, Tempkin isotherm model showed a better representation of the equilibrium data with a good correlation coefficient (R 2 ) greater than 0.99. The FT-IR results gave an indication of the possible functional groups located on the surface of the groundnut shell. These groups influe...
Potentially toxic trace elements such as lead when present in high levels in water, food and soil... more Potentially toxic trace elements such as lead when present in high levels in water, food and soil post serious human health threats all over the world. Adsorption process using different natural materials is among the most effective techniques for removing many heavy metal ions from different types of water sources. In this study, an attempt has been made to investigate the efficiency of groundnut shells for removing lead from aqueous solutions using batch mode technique. The equilibrium data was analyzed using one one-parameter, six two-parameter and two three-parameter adsorption isotherm models. The experimental data fitted well to twoparameter isotherm (Tempkin adsorption isotherm) in comparison to the other adsorption isotherm models analyzed. The correlation coefficient of Tempkin adsorption isotherm was found to be 0.9661 indicating that the groundnut shell could remove about 96.61 % of Pb (II) ions effectively from the aqueous solution.Fourier transform infrared (FT-IR) spec...
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