Browsing by Author "Bayuo, Jonas"

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Adsorption and desorption processes of toxic heavy metals, regeneration and reusability of spent adsorbents: Economic and environmental sustainability approach
(Elsevier, 2024-05-19) Bayuo, Jonas; Rwiza, Mwemezi; Choi, Joon; Mtei, Kelvin; Hosseini-Bandegharaei, Ahmad; Sillanpää, Mika
A growing number of variables, including rising population, water scarcity, growth in the economy, and the existence of harmful heavy metals in the water supply, are contributing to the increased demand for wastewater treatment on a global scale. One of the innovative water treatment technologies is the adsorptive removal of heavy metals through the application of natural and engineered adsorbents. However, adsorption currently has setbacks that prevent its wider application for heavy metals sequestration from aquatic environments using various adsorbents, including difficulty in selecting suitable desorption eluent to recover adsorbed heavy metals and regeneration techniques to recycle the spent adsorbents for further use and safe disposal. Therefore, the recovery of adsorbed heavy metal ions and the ability to reuse the spent adsorbents is one of the economic and environmental sustainability approaches. This study presents a state-of-the-art critical review of different desorption agents that could be used to retrieve heavy metals and regenerate the spent adsorbents for further adsorption-desorption processes. Additionally, an attempt was made to discuss and summarize some of the independent factors influencing heavy metals desorption, recovery, and adsorbent regeneration. Furthermore, isotherm and kinetic modeling have been summarized to provide insights into the adsorption-desorption mechanisms of heavy metals. Finally, the review provided future perspectives to provide room for researchers and industry players who are interested in heavy metals desorption, recovery, and spent adsorbents recycling to reduce the high cost of adsorbents reproduction, minimize secondary waste generation, and thereby provide substantial economic and environmental benefits.
Adsorptive Removal of Heavy Metals from Wastewater Using Low-Cost Adsorbents Derived from Agro-based Materials.
(Springer Nature, 2024-03-29) Bayuo, Jonas; Rwiza, Mwemezi; Mtei, Kelvin
Recently, anthropogenic activities have evolved into sources of pollution, particularly when it comes to the discharge of harmful heavy metals into the natural environment. As a result, the concentration of diverse heavy metal ions in surface and ground waters significantly increases, compromising aquatic life. Given that toxic heavy metals have undesirable consequences on the health of all living things, their presence in the aquatic environment is a major worry. However, the drawbacks of conventional wastewater treatment technologies, such as their high consumption of energy, production of hazardous secondary sludge, and high operating costs, made them uneconomical and non-sustainable for developing nations. This book chapter presents and discusses the most recent developments and advances in the adsorptive removal of various heavy metals from aquatic systems through the application of low-cost adsorbents derived from agricultural waste materials. The influence of independent adsorption parameters as well as the mechanism of heavy metals removal from aqueous media have been explained using adsorption isotherm and kinetic models. This book chapter has demonstrated that the adsorptive removal of heavy metals using low-cost adsorbents derived from agricultural waste materials has several advantages. Almost all the studies on the adsorptive decontamination of various heavy metals from aqueous solutions revealed that adsorbents synthesized from agro-based materials are promising, eco-friendly, and cost-effective. However, several gaps exist, which need to be addressed to increase the application of the adsorption technology in treating industrial wastewater at a large scale. Hence, at the end of this book chapter, some future perspectives providing knowledge gaps that require consideration and further research have been enumerated.
Applicability of bio-adsorbents synthesized from maize/corn plant residues for heavy metals removal from aquatic environments: an insight review
(EQA-International Journal of Environmental Quality, 2023-07-14) Bayuo, Jonas; Rwiza, Mwemezi; Mtei, Kelvin
The underutilization of agricultural waste products in recent years has resulted in environmental issues owing to improper disposal. As a result, heavy metals removal from aqueous systems utilizing sorbent materials produced from agricultural wastes has received a lot of attention. The current study provides an insightful review of the use of bio-adsorbents synthesized from maize/corn residues to decontaminate various toxicants from wastewater. Although bio-adsorbents made from maize/corn residues have shown to be efficient in the sequestration of heavy metals from wastewater, no study has looked at hybrid bio-adsorbents made from various parts of the maize/corn plant. Moreover, all studies practically investigate the sorption processes using the one-factor design technique, which exceedingly consumes time and is expensive for a significant number of biosorption/adsorption factors. Besides, the majority of the studies used bio-adsorbents produced from maize/corn biomass to remove heavy metals from single sorption systems. Furthermore, very few studies have focussed on heavy metals desorption from the exhausted maize/corn bio-adsorbents following the adsorption process to recycle the spent bio-adsorbents for future usage, which would be more cost-effective. Based on the gaps revealed in this review, it is recommended that further investigations on the usefulness of bio-adsorbents derived from maize/corn biomass in cleansing different water toxicants should be carried out.
Applicability of bio-adsorbents synthesized from maize/corn plant residues for heavy metals removal from aquatic environments:an insight review
(International Journal of Environmental Quality, 2023-07-04) Bayuo, Jonas; Mtei, Kelvin; Rwiza, Mwemezi
The underutilization of agricultural waste products in recent years has resulted in environmental issues owing to improper disposal. As a result, heavy metals removal from aqueous systems utilizing sorbent materials produced from agricultural wastes has received a lot of attention. The current study provides an insightful review of the use of bio-adsorbents synthesized from maize/corn residues to decontaminate various toxicants from wastewater. Although bio-adsorbents made from maize/corn residues have shown to be efficient in the sequestration of heavy metals from wastewater, no study has looked at hybrid bio-adsorbents made from various parts of the maize/corn plant. Moreover, all studies practically investigate the sorption processes using the one-factor design technique, which exceedingly consumes time and is expensive for a significant number of biosorption/adsorption factors. Besides, the majority of the studies used bio-adsorbents produced from maize/corn biomass to remove heavy metals from single sorption systems. Furthermore, very few studies have focussed on heavy metals desorption from the exhausted maize/corn bio-adsorbents following the adsorption process to recycle the spent bio-adsorbents for future usage, which would be more cost-effective. Based on the gaps revealed in this review, it is recommended that further investigations on the usefulness of bio-adsorbents derived from maize/corn biomass in cleansing different water toxicants should be carried out.
Artisanal and small-scale mining in Tanzania and health implications: A policy perspective
(Elsevier, 2023-03-17) Rwiza, Mwemezi; Focus, Erasto; Bayuo, Jonas; Kimaro, Joseph; Kleinke, Matthias; Lyasenga, Theresia; Mosses, Jerry; Marwa, Janeth
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.
Biochar-based technology in water and wastewater treatment
(Elsevier Inc., 2025) Bayuo, Jonas; Alayande, Abayomi; Mtei, Kelvin; Rwiza, Mwemezi
This book chapter summarizes the most recent developments in the utilization of biochar technology for treating environmental pollutants from wastewater, including industrial, agricultural, municipal, and stormwater. It starts by discussing biochar as a concept, the type of biomass feedstocks from which biochar can be synthesized, and the properties of biochar. Also, the elemental composition, surface chemistry, and the characterization of the biochar using different instruments have been elucidated. The ability of biochar to remove different contaminants from water systems has been insighfully discussed in this book chapter, although there are still certain knowledge gaps requiring to be addressed. Therefore, at the concluding end of this book chapter, future prospectives for the selection, preparation, and application of biocharbased materials have been proposed. This book chapter will be very beneficial to new researchers and other scholars to systematically gain insight into the research advancements on biocharbased sorbent materials in environmental remediation.
A comprehensive review on the decontamination of lead(II) from water and wastewater by low-cost biosorbents
(Royal Society of Chemistry, 2022-04-12) Bayuo, Jonas; Rwiza, Mwemezi; Mtei, Kelvin
The disadvantages of conventional methods in water and wastewater management including the demand for high energy consumption, the creation of secondary toxic sludge, and operation cost are much too high for developing countries. However, adsorption using low-cost biosorbents is the most efficient nonconventional technique for heavy metals removal. The high adsorption capacities, cost-effectiveness, and the abundance of agricultural waste materials in nature are the important parameters that explain why these biosorbents are economical for heavy metals removal. The present investigation sought to review the biosorption of lead [Pb(II)] onto low-cost biosorbents to understand their adsorption mechanism. The review shows that biosorption using low-cost biosorbents is eco-friendly, costeffective, and is a simple technique for water and wastewater treatment containing lead(II) ions. The batch biosorption tests carried out in most studies show that Pb(II) biosorption by the low-cost biosorbents is dependent on biosorption variables such as pH of the aqueous solution, contact time, biosorbent dose, Pb(II) initial concentration, and temperature. Furthermore, batch equilibrium data have been explored in many studies by evaluating the kinetics, isothermal and thermodynamic variables. Most of the studies on the adsorptive removal of Pb(II) were found to follow the pseudo-second kinetic and Langmuir isotherm models with the thermodynamics variables suggesting the feasibility and spontaneous nature of Pb(II) sequestration. However, gaps exist to increase biosorption ability, economic feasibility, optimization of the biosorption system, and desorption and regeneration of the used agricultural biosorbents.
Green adsorbent from maize biomass for mercury capture: insights from sorption modeling and thermodynamic analysis
(Applied Water Science, 2025-07-05) Bayuo, Jonas; Mwemezi, Rwiza; Oyelude, Emmanuel; Mtei, Kelvin; Joon Weon Choi
Adsorption isotherms and kinetics modeling, as well as thermodynamic analysis, are useful in providing insight into the nature and mechanisms of the adsorption process. The present study investigated the interactive behavior and mechanisms of mercury ions removal using activated carbon produced from maize biomass (bio-adsorbent). To determine the mechanism of mercury removal from the aqueous system using the activated carbon, the equilibrium adsorption isotherm, kinetics, and thermodynamic studies were performed using the batch technique. Among all the isotherm models analyzed, the Langmuir isotherm model best correlated with the equilibrium sorption data of Hg(II) attained by the bio-adsorbent with a high correlation coefficient of 0.9998. The Langmuir maximum monolayer sorption capacity attained by the bio-adsorbent was 112.46 mg/g, and the dimensionless separation factor ( RL) was in the range of 0.00 < RL > 1.00 indicating favorable biosorption. The pseudo-second-order model well fitted the experimental data of Hg(II) better than the other kinetic models with a high correlation coefficient of 0.9712, which is close to unity with an uptake capacity of 82.10 mg/g. The negative values of ΔG0 obtained from all the temperature ranges of 283–358 K indicate the spontaneous nature of Hg(II) ions removal from the adsorption system by the bio-adsorbent. The positive value of + 24.86 kJ/mol and + 8.13 kJ/mol attained for ΔH0 and ΔS0 , respectively, indicates endothermic adsorption and an upsurge in disorder during the adsorptive removal of Hg(II) ions. Therefore, the study found that the activated carbon not only interacted well with the Hg(II) species in the aqueous solutions but also had a high uptake capacity. Hence, the bio-adsorbent is promising and could efficiently be applied for heavy metal remediation in aquatic environments.
Modeling and optimization of independent factors influencing lead(II) biosorption from aqueous systems: A statistical approach
(Elsevier, 2022-07) Bayuo, Jonas; Rwiza, Mwemezi; Abukari, Moses; Pelig-Ba, Kenneth; Mtei, Kelvin
Lead, [Pb(II)] is a major hazardous contaminant that exists in the soil, surface, and groundwater as a result of human activities. It is carcinogenic in nature and causes damage to the liver, kidney, and bones as well as the digestive, respiratory, and immune systems. As a result, the main purpose of this study was to prepare and employ modified powdered peanut shells as a biosorbent in the decontamination of lead(II) ions from aqueous solutions. The removal of lead(II) onto the biosorbent was modeled and optimized using the response surface methodology and the effects of three biosorption variables on two response variables were investigated using the central composite design of the response surface methodology. The optimization of lead(II) removal by the biosorbent shows that contact time, pH, and initial concentration had a significant influence on the removal efficiency and biosorption capacity of lead(II). This was shown by the response surface methodology where the interaction among the independent variables studied improved the biosorption of lead(II). Applying the central composite design, the optimized contact time ( min), pH (), and initial concentration ( mg/L) gave a removal of and biosorption capacity of mg/g of lead(II) with the desirability of . The study revealed that the modified powdered peanut shells, a low-cost biosorbent was efficient in decontaminating lead(II) ions in the aqueous solutions. However, the biosorption process optimization was dependent on contact time, pH, and initial lead(II) concentration. The study recommends that the untreated form of the peanut shells should be used and the results compared with the present study.
Modeling and optimization of trivalent arsenic removal from wastewater using activated carbon produced from maize plant biomass: a multivariate experimental design approach
(Springer Nature Limited, 2023-06-24) Bayuo, Jonas; Rwiza, Mwemezi; Mtei, Kelvin
Globally, both industrialized and developing nations struggle with the issue of water pollution due to heavy metals. Human life depends on water, and when it is contaminated with dangerous heavy metals like arsenic, people’s health suffers. The interactive influence of three independent sorption processes variables such as bio-adsorbent dosage (0.50–3.00 g/L), contact time (40.00–90.00 min), and initial concentration (10.00–30.00 mg/L) on the modeling and optimization of trivalent arsenic removal from wastewater was studied in a batch mode using multivariate experimental design. The quadratic models provided accurate predictions for the response variables with high coefficients of correlation of 0.9984 and 0.9994 for removal and uptake rates, respectively. The developed models were accurate and exhibited a remarkable correlation between the observed and projected data according to the diagnostic test analyses. Through the analysis of variance, all the studied adsorption factors were statistically significant (p-values < 0.0001) with initial concentration and bio-adsorbent dosage producing the main interactive effect on the percentage removal and adsorption capacity with F-values of 146.05 and 264.65, respectively. The optimum operating conditions attained were 90.00 min contact time, 0.50 g/L bio-adsorbent dosage, and an initial concentration of 10.00 mg/L, which gave arsenic maximum removal and uptake efficiencies of 93.14% and 7.04 mg/g, correspondingly with the desirability of 0.844. Confirmative tests were conducted under the optimized conditions to validate the accuracy of the models in which a maximum removal efficacy of 94.33% and adsorption capacity of 7.15 mg/g were achieved. The applicability of the bio-adsorbent in the adsorption of arsenic in textile industrial wastewater was also tested and the bio-adsorbent could competitively decontaminate over 99% of arsenic species from the wastewater.
Non-competitive and competitive detoxification of As (III) ions from single and binary biosorption systems and biosorbent regeneration
(Springer Nature Switzerland AG., 2023-01-14) Bayuo, Jonas; Rwiza, Mwemezi; Mtei, Kelvin
The quantity of studies reporting on single-metal sorption systems is increasing every day while the elimination of heavy metals in binary and multisolute systems is seldom reported. Therefore, the biosorption and desorption of arsenic from single and binary systems on hybrid granular activated carbon have been investigated using the batch technique. The hybrid granular activated carbon was characterized using Fourier transform infrared spectrometer and Brunauer–Emmett–Teller, and the results showed that the biosorbent surface characteristics could facilitate arsenic removal from the non- and competitive biosorption media. The main biosorption mechanisms of arsenic on the biosorbent involved surface complexation, electrostatic attraction, and replacement of hydroxyl groups. Furthermore, the effective elimination of arsenic was discovered to be reliant on the sorbent’s physicochemical properties as well as all the studied independent biosorption factors. The equilibrium sorption data of both the single and binary systems were best explained by the Langmuir and pseudo-second-order models, indicating the mechanism of arsenic biosorption was mainly chemisorption. The Langmuir maximum monolayer sorption capacities of the biosorbent were 205.76 and 153.09 mg/g for the single and binary systems, respectively. While the evaluated thermodynamic parameters suggest that the biosorption removal of arsenic from both sorption systems was spontaneous and endothermic with increasing randomness at the liquid–solid interface, the successive biosorption–desorption studies indicated that the exhausted biosorbent can be renewed without a substantial deterioration in its uptake capacity even after the seventh regeneration cycle. This indicates that the biosorbent has the economic potential to be used repeatedly in arsenic species sequestration from wastewater.
Optimization of arsenic(III) and mercury(II) removal from non-competitive and competitive sorption systems onto activated carbon
(NM-AIST, 2024-07) Bayuo, Jonas
Heavy metals exist in the ecosystem both naturally and due to anthropogenic activities and as recalcitrant pollutants; they are non-biodegradable and cause acute and chronic diseases to human beings and many lifeforms. As a result, the removal of heavy metals from aqueous systems using sorbent materials produced from agricultural wastes is one of the new innovative treatment techniques. In this study, the biosorption and desorption characteristics of heavy metal ions from non-competitive and competitive aqueous solutions onto hybrid granular activated carbon produced from maize residues were investigated. The efficient sequestration of As(III) and Hg(II) ions from both monocomponent and bicomponent synthetic wastewater was found to show dependence on the physicochemical properties of the biosorbent and the studied independent biosorption process factors. The regenerated biosorbent could be reused up to the eighth cycle for the sequestration of As(III) and Hg(II) ions from the synthetic wastewater without significantly losing its adsorptive properties. The applicability of the biosorbent synthesized from the maize residues for the simultaneous decontamination of heavy metals found in real industrial wastewater as a function of several biosorption factors showed that the biosorbent could competitively decontaminate over 96% of As, Hg, Pb, Cd, and Cr in 100 mL textile wastewater in batch mode. The regeneration of the spent biosorbent using 0.10 M HCl showed that the biosorbent is capable of being recycled and reused severally for the sequestration of As, Hg, Pb, Cd, and Cr from the textile wastewater and even up to the ten cycles for a duration of 4 h. The optimization of the competitive removal of As and Hg ions in the co-existence of other heavy metals in the textile wastewater by the CCD-RSM resulted in maximum removal efficiencies of 97.72 and 99.99%, respectively. The characterization of the hybrid granular activated carbon using SEM, TEM, XRD, BET, and FTIR showed that the biosorbent surface characteristics could facilitate the removal of heavy metals from the non competitive and competitive biosorption media. The main biosorption mechanism of the heavy metal ions on the biosorbent was mainly chemisorption involving surface complexation. Therefore, this novel biosorbent is found to be promising and could effectively be employed for heavy metals remediation in aquatic environments. The outcomes of this study are expected to make a significant contribution to the design of low-cost and efficient industrial wastewater treatment systems such as a dynamic batch rector for heavy metal removal using locally available bio-adsorbents.
Optimization of desorption parameters using response surface methodology for enhanced recovery of arsenic from spent reclaimable activated carbon: Eco-friendly and sorbent sustainability approach
(Elsevier Inc., 2024-06-05) Bayuo, Jonas; Rwiza, Mwemezi; Choi, Joon; Sillanpaa, Mika; Mtei, Kelvin
Desorption and adsorbent regeneration are imperative factors that are required to be taken into account when designing the adsorption system. From the environmental, economic, and practical points of view, regeneration is necessary for evaluating the efficiency and sustainability of synthesized adsorbents. However, no study has investigated the optimization of arsenic species desorption from spent adsorbents and their regeneration ability for reuse as well as safe disposal. This study aims to investigate the desorption ability of arsenic ions adsorbed on hybrid granular activated carbon and the optimization of the independent factors influencing the efficient re- covery of arsenic species from the spent activated carbon using central composite design of the response surface methodology. The activated carbon before the sorption process and after the adsorption-desorption of arsenic ions have been characterized using SEM-EDX, FTIR, and TEM. The study found that all the investigated inde- pendent desorption variables greatly influence the retrievability of arsenic ions from the spent activated carbon. Using the desirability function for the optimization of the independent factors as a function of desorption effi- ciency, the optimum experimental conditions were solution pH of 2.00, eluent concentration of 0.10 M, and temperature of 26.63 ℃, which gave maximum arsenic ions recovery efficiency of 91 %. The validation of the quadratic model using laboratory confirmatory experiments gave an optimum arsenic ions desorption efficiency of 97 %. Therefore, the study reveals that the application of the central composite design of the response surface methodology led to the development of an accurate and valid quadratic model, which was utilized in the enhanced optimization of arsenic ions recovery from the spent reclaimable activated carbon. More so, the desorption isotherm and kinetic data of arsenic were well correlated with the Langmuir and the pseudo-second- order models, while the thermodynamics studies indicated that arsenic ions desorption process was feasible, endothermic, and spontaneous.
Optimization of divalent mercury removal from synthetic wastewater using desirability function in central composite design of response surface methodology
(Springer Naturer, 2023-12-07) Bayuo, Jonas; Rwiza, Mwemezi; Mtei, Kelvin
Heavy metals exist in the ecosystem both naturally and due to anthropogenic activities and as recalcitrant pollutants; they are non-biodegradable and cause acute and chronic diseases to human beings and many lifeforms. A statistical experimental approach was applied in this current study to optimize the detoxification of mercury [Hg(II)] from mono-component biosorption system by a novel hybrid granular activated carbon (biosorbent) prepared from maize plant residues. The analysis of variance by the application of central composite design shows that all the studied independent factors greatly influence Hg(II) removal efficiency and uptake capacity. The optimum experimental condition of 30 min contact time, 0.5 g/L biosorbent dosage, and 15 mg/L initial Hg(II) concentration were achieved after seeking 20 optimization solutions at 0.903 desirability. The optimum percentage removal and uptake capacity of Hg(II) at the optimal experimental setup was 96.7% and 10.8 mg/g, respectively. To confirm the quadratic models developed for the prediction of the responses as a function of the independent factors, confirmatory laboratory experiments were performed at the optimum condition. The results show that at the established best experimental condition, the optimum Hg(II) removal efficiency of 98.3% and uptake capacity of 11.2 mg/g were attained, which were within the prediction intervals indicating the suitability of the quadratic models in predicting future cases. The TEM and XRD analyses show that the Hg(II) ions were adsorbed by the biosorbent successfully and this suggests the potential and applicability of this novel biosorbent in treating water contaminants, especially heavy metals.
Recent and sustainable advances in phytoremediation of heavy metals from wastewater using aquatic plant species: Green approach
(Elsevier, 2024-11) Bayuo, Jonas; Rwiza, Mwemezi; Choi, Joon; Njau, Karoli; Mtei, Kelvin
A key component in a nation's economic progress is industrialization, however, hazardous heavy metals that are detrimental to living things are typically present in the wastewater produced from various industries. Therefore, before wastewater is released into the environment, it must be treated to reduce the concentrations of the various heavy metals to maximum acceptable levels. Even though several biological, physical, and chemical remediation techniques are found to be efficient for the removal of heavy metals from wastewater, these techniques are costly and create more toxic secondary pollutants. However, phytoremediation is inexpensive, environmentally friendly, and simple to be applied as a green technology for heavy metal detoxification in wastewater. The present study provides a thorough comprehensive review of the mechanisms of phytoremediation, with an emphasis on the possible utilization of plant species for the treatment of wastewater containing heavy metals. We have discussed the concept, its applications, advantages, challenges, and independent variables that determine how successful and efficient phytoremediation could be in the decontamination of heavy metals from wastewater. Additionally, we argue that the standards for choosing aquatic plant species for target heavy metal removal ought to be taken into account, as they influence various aspects of phytoremediation efficiency. Following the comprehensive and critical analysis of relevant literature, aquatic plant species are promising for sustainable remediation of heavy metals. However, several knowledge gaps identified from the review need to be taken into consideration and possibly addressed. Therefore, the review provides perspectives that indicate research needs and future directions on the application of plant species in heavy metal remediation.
Removal of heavy metals from binary and multicomponent adsorption systems using various adsorbents – a systematic review
(Research Society of Chemistry, 2023) Bayuo, Jonas; Rwiza, Mwemezi; Sillanpää, Mika; Mtei, Kelvin
The ecosystem and human health are both significantly affected by the occurrence of potentially harmful heavy metals in the aquatic environment. In general, wastewater comprises an array of heavy metals, and the existence of other competing heavy metal ions might affect the adsorptive elimination of one heavy metal ion. Therefore, to fully comprehend the adsorbent's efficiency and practical applications, the abatement of heavy metals in multicomponent systems is important. In the current study, the multicomponent adsorption of heavy metals from different complex mixtures, such as binary, ternary, quaternary, and quinary solutions, utilizing various adsorbents are reviewed in detail. According to the systematic review, the adsorbents made from locally and naturally occurring materials, such as biomass, feedstocks, and industrial and agricultural waste, are effective and promising in removing heavy metals from complex water systems. The systematic study further discovered that numerous studies evaluate the adsorption characteristics of an adsorbent in a multicomponent system using various important independent adsorption parameters. These independent adsorption parameters include reaction time, solution pH, agitation speed, adsorbent dosage, initial metal ion concentration, ionic strength as well as reaction temperature, which were found to significantly affect the multicomponent sorption of heavy metals. Furthermore, through the application of the multicomponent adsorption isotherms, the competitive heavy metals sorption mechanisms were identified and characterized by three primary kinds
Response surface optimization and modeling in heavy metal removal from wastewater—a critical review
(Springer Nature, 2022-04-08) Bayuo, Jonas; Rwiza, Mwemezi
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.