Evans Dovi - Academia.edu (original) (raw)

Papers by Evans Dovi

Research Square (Research Square), Jun 16, 2021

The presence of emerging pollutants such as PO4 3and NO3in water bodies has attracted worldwide c... more The presence of emerging pollutants such as PO4 3and NO3in water bodies has attracted worldwide concern about their severe effects on water bodies and the health of humankind in general. Therefore, to preserve the health of humankind and environmental safety, it is of the essence that industrial effluents are treated before they are discharged into water bodies. To accomplish this, the walnut shell was functionalized (ACWNS) with amine for effective removal of PO4 3and NO3-. Characterization studies of ACWNS were conducted using FTIR, XRD, XPS and BET techniques. Removal of both ions was enhanced at lower temperature (293 K). The maximum uptake capacity of phosphate and nitrate, at 293 K, was 82.2 and 35.7 mg g-1 , respectively. The primary mechanism by which these ions were uptaken onto ACWNS could be electrostatic interactions and hydrogen bonding.Pseudosecond-order kinetics fitted the PO4 3̶ and NO3adsorption, while Freundlich and Langmuir models best fitted the PO4 3̶ and NO3 ̶ adsorption, respectively. Furthermore, in the binary system, the uptake capacity of phosphate decreased by 14.4% while nitrate witnessed a reduction in its uptake capacity by 10.4 %. So ACWNS has a higher attraction towards both ions and this could be attributed to the existence of a variety of active areas on ACWNS that exhibit a degree of specificity for the individual anions. Results obtained from real water samples analysis confirmed ACWNS as highly efficient to be utilized for practical remediation processes.

Journal of Colloid and Interface Science, Sep 1, 2021

Accessibility to quality and clean water has in recent times been compromised due to the presence... more Accessibility to quality and clean water has in recent times been compromised due to the presence of pollutants, thus posing as a threat to the survival of living organisms. The adsorption technique in this regard has been observed to be useful in the remediation process with the material used as the adsorbent playing an integral role. In this study, a novel biocomposite (PN-Fe3O4-IDA-Al) based on peanut husk (a low-cost material) was developed by functionalization with aluminum (Al), iminodiacetic acid (IDA) and Fe3O4. The efficiency of PN-Fe3O4-IDA-Al as an adsorbent for the remediation of wastewater was evaluated using Congo red (CR) and phosphates (PO43-) as model pollutants. The results from the characterization studies confirmed PN-Fe3O4-IDA-Al to have superparamagnetic properties which ensures its easy retrieval. Adsorption studies indicated that PN-Fe3O4-IDA-Al had a maximum monolayer capacity of 79.0 ± 2.0 and 16.8 ± 2.5 mg g-1 for CR and PO43- (according to P), respectively, which was significantly dependent on factors such as reaction time, solution pH, temperature and the presence of some common anions. The Freundlich model was observed to better describe both adsorption processes with chemisorption being the principal underlying mechanism. Results from using real water samples confirmed PN-Fe3O4-IDA-Al to be highly efficient for practical remediation processes. These results coupled with the synthesis of PN-Fe3O4-IDA-Al under benign conditions using low-cost materials help to expound the knowledge on the use of low cost materials as the basis for the development of highly efficient adsorbents for wastewater remediation.

Environmental Science and Pollution Research, Jul 23, 2022

Environmental Science and Pollution Research, Apr 26, 2022

We engineered a tiger nut residue (TNR, a low-cost agricultural waste material) through a facile ... more We engineered a tiger nut residue (TNR, a low-cost agricultural waste material) through a facile and simple process to take advantage of the introduced functional groups (cetylpyridinium chloride, CPC) in the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) in batch mode and further investigated its impingement on bacterial growth in a yeast-dextrose broth. The surface characterizations of the adsorbent were achieved through Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller method (BET), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The batch adsorption studies revealed that solution pH, adsorbent dose, temperature, and salt affected the adsorptive capacity of TNR-CPC. The equilibrium data were best fitted by Langmuir isotherm model with a maximum monolayer adsorption capacity of 90.2 mg g–1 at 318 K and pH 3. Pseudo-second-order model best fitted the kinetics data for the adsorption process. Physisorption largely mediated the adsorption system with spontaneity and a shift in entropy of the aqueous solid-solute interface reflecting decreased randomness with an exothermic character. TNR-CPC demonstrated a good reusability potential making it highly economical and compares well with other adsorbents for decontamination of 2,4-D. The adsorption of 2,4-D proceeded through a probable trio-mechanism; electrostatic attraction between the carboxylate anion of 2,4-D and the pyridinium cation of TNR-CPC, hydrogen bonding between the hydroxyl (–OH) group inherent in the TNR and the carboxyl groups in 2,4-D and a triggered π-π stacking between the benzene structures in the adsorbate and the adsorbent. TNR-CPC reported about 99% inhibition rate against both gram-positive S. aureus and gram-negative E. coli. It would be appropriate to investigate the potential of TNR-CPC as a potential replacement to the metal oxides used in wastewater treatment for antibacterial capabilities, and its effects against airborne bacteria could also be of interest.

Environmental Science and Pollution Research, Mar 13, 2021

A novel adsorbent (PN-Fe3O4-IDA-Zr) was developed from the chemical modification of peanut husk (... more A novel adsorbent (PN-Fe3O4-IDA-Zr) was developed from the chemical modification of peanut husk (a low cost material) with Fe3O4, iminodiacetic acid (IDA) and zirconium (Zr) and its efficacy for the sequestration of wastewater assessed using Alizarin red (AR) and Acid chrome blue K (AK) as model pollutants. To elucidate the characteristics of the formed adsorbent, analytical techniques such as the Bruauner-Emmet-Teller (BET) method, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractive spectroscopy (XRD) and vibrating sample magnetometer (VSM) were applied. Results from these studies confirmed the formation of a crystalline mesoporous adsorbent with surface properties which enhanced its usefulness. From the adsorption studies, it was observed that factors such as pH, salts, temperature and contact time influenced the uptake of the anionic dyes. The maximum monolayer capacity of PN-Fe3O4-IDA-Zr for AR was 49.4 mg g−1 (at 313 K) and was well fitted by the Langmuir model with the chemisorption process being the dominant reaction mechanism. In binary systems, PN-Fe3O4-IDA-Zr exhibited higher affinity for AR as compared with AK. The significant removal efficiency exhibited by this novel adsorbent as well as other unique features such as easy retrieval and high regeneration promotes its prospects as an adsorbent for practical wastewater remediation processes.

Colloids and Surfaces A: Physicochemical and Engineering Aspects, Apr 1, 2021

Abstract The development of adsorbents based on agricultural biomass for the remediation of pollu... more Abstract The development of adsorbents based on agricultural biomass for the remediation of polluted waters offers unique benefits and also fits into the concept of green chemistry. In this study, a highly efficient adsorbent (PN-Fe3O4-IDA-Zr) based on peanut husk chemically modified with zirconium, iminodiacetic acid and Fe3O4 was employed for the sequestration of phosphates in synthetic and real water samples. The characterization of PN-Fe3O4-IDA-Zr via analytical techniques confirmed it as a crystalline mesoporous adsorbent with superparamagnetic properties which ensures its easy retrieval from the solution under an external magnetic field. The adsorption capacity and associated mechanisms of the adsorbent were assessed via the batch method. Results from adsorption studies showed the maximum adsorption capacity of PN-Fe3O4-IDA-Zr for PO43− (50 mg L−1, mass as P) to be 13.2 mg g−1 at 313 K and was influenced by factors such as contact time, pH, initial phosphate concentration, salts and temperature. The experimental data were well fitted by the Freundlich model and Elovich equation suggesting the formation of a multilayer on the surface of PN-Fe3O4-IDA-Zr which was mainly influenced by the chemisorption process (mainly via coordination). A comparison of the efficiencies of the adsorbent at its various stages of development shows that the presence of zirconium plays a significant role in the adsorption process thus confirming the design concept of the adsorbent. PN-Fe3O4-IDA-Zr exhibited high stability and efficiency in real water samples that were spiked with high concentrations of phosphates. These results as well as the facile synthetic route for PN-Fe3O4-IDA-Zr under benign conditions promote its prospects as a promising adsorbent for practical applications.

Environmental Science and Pollution Research, Nov 8, 2021

The presence of emerging pollutants such as PO43− and NO3− in water bodies has attracted worldwid... more The presence of emerging pollutants such as PO43− and NO3− in water bodies has attracted worldwide concern about their severe effects on water bodies and the health of humankind in general. Therefore, to preserve the health of humankind and environmental safety, it is of the essence that industrial effluents are treated before they are discharged into water bodies. Amine functionalized walnut shells (ACWNS) were synthesized, characterized, and then tested as a novel adsorbent for PO43− and NO3− removal. The effects of pH, dosage, initial phosphate concentration, interference ions, and temperature on the removal of phosphate and nitrate were investigated. Notably, the adsorption of PO43− and NO3− was exothermic and spontaneous, with a maximum uptake capacity of phosphate and nitrate, at 293 K, 82.2 and 35.7 mg g−1, respectively. The mechanism by which these ions were adsorbed onto ACWNS could be electrostatic interactions and hydrogen bonding. Pseudo-second-order kinetic model fitted the PO43− and NO3− adsorption, while Freundlich and Langmuir models best fitted the PO43− and NO3− adsorption, respectively. Furthermore, in the binary system, the uptake capacity of phosphate decreased by 14.4% while nitrate witnessed a reduction in its uptake capacity of 10.4%. ACWNS has a higher attraction towards both ions and this could be attributed to the existence of a variety of active areas on ACWNS that exhibit a degree of specificity for the individual ions. Results obtained from real water sample analysis confirmed ACWNS as highly efficient to be utilized for practical remediation processes.

Chemosphere, 2022

A biocomposite (PN-Fe3O4-PEI) was synthesized via the chemical modification of peanut husk (a low... more A biocomposite (PN-Fe3O4-PEI) was synthesized via the chemical modification of peanut husk (a low-cost adsorbent) with Fe3O4 particles and polyethyleneimine under benign environmental conditions. The modification agents used in this study were observed to overcome the challenges associated with the use pristine peanut husk with a concomitant enhancement in its efficiency as an adsorbent. Results from the characterization studies employed in this study confirmed PN-Fe3O4-PEI to be a crystalline magnetic adsorbent with a mesoporous structure. The adsorption property of the developed material (PN-Fe3O4-PEI) for wastewater treatment was investigated using Chromium (VI), Phosphates (PO43-) and Congo red (CR) as model pollutants. Using the batch method, PN-Fe3O4-PEI exhibited a maximum monolayer adsorption capacity of 58.4, 13.5 and 71.3 mg g-1 for Cr(VI), PO43- (as P g L-1) and CR, respectively and was dependent on temperature and initial adsorbate concentration. Kinetic studies revealed that the Elovich equation, the pseudo-second order kinetic model and double constant equation well described the uptake of Cr(VI), PO43- and CR onto PN-Fe3O4-PEI, respectively. These results may confirm the uptake of these pollutants to be mainly driven by chemical forces. In addition, PN-Fe3O4-PEI was observed to be efficient for the decontamination of the studied pollutants in real water samples as well as exhibit antibacterial properties towards the growth of S. aureus. These properties of PN-Fe3O4-PEI with its other excellent features such as high stability in solution, good regeneration properties and its facile retrieval from the solution using a magnet promote its suitability for practical wastewater treatment.

Chinese Journal of Chemical Engineering, Aug 1, 2023

Chinese Journal of Chemical Engineering

Environmental Science and Pollution Research

We engineered a tiger nut residue (TNR, a low-cost agricultural waste material) through a facile ... more We engineered a tiger nut residue (TNR, a low-cost agricultural waste material) through a facile and simple process to take advantage of the introduced functional groups (cetylpyridinium chloride, CPC) in the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) in batch mode and further investigated its impingement on bacterial growth in a yeast-dextrose broth. The surface characterizations of the adsorbent were achieved through Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller method (BET), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The batch adsorption studies revealed that solution pH, adsorbent dose, temperature, and salt affected the adsorptive capacity of TNR-CPC. The equilibrium data were best fitted by Langmuir isotherm model with a maximum monolayer adsorption capacity of 90.2 mg g–1 at 318 K and pH 3. Pseudo-second-order model best fitted the kinetics data for the adsorption process. Physisorption largely mediated the adsorption system with spontaneity and a shift in entropy of the aqueous solid-solute interface reflecting decreased randomness with an exothermic character. TNR-CPC demonstrated a good reusability potential making it highly economical and compares well with other adsorbents for decontamination of 2,4-D. The adsorption of 2,4-D proceeded through a probable trio-mechanism; electrostatic attraction between the carboxylate anion of 2,4-D and the pyridinium cation of TNR-CPC, hydrogen bonding between the hydroxyl (–OH) group inherent in the TNR and the carboxyl groups in 2,4-D and a triggered π-π stacking between the benzene structures in the adsorbate and the adsorbent. TNR-CPC reported about 99% inhibition rate against both gram-positive S. aureus and gram-negative E. coli. It would be appropriate to investigate the potential of TNR-CPC as a potential replacement to the metal oxides used in wastewater treatment for antibacterial capabilities, and its effects against airborne bacteria could also be of interest.

Journal of Environmental Chemical Engineering, 2022

Environmental Science and Pollution Research, 2021

A novel adsorbent (PN-Fe3O4-IDA-Zr) was developed from the chemical modification of peanut husk (... more A novel adsorbent (PN-Fe3O4-IDA-Zr) was developed from the chemical modification of peanut husk (a low cost material) with Fe3O4, iminodiacetic acid (IDA) and zirconium (Zr) and its efficacy for the sequestration of wastewater assessed using Alizarin red (AR) and Acid chrome blue K (AK) as model pollutants. To elucidate the characteristics of the formed adsorbent, analytical techniques such as the Bruauner-Emmet-Teller (BET) method, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractive spectroscopy (XRD) and vibrating sample magnetometer (VSM) were applied. Results from these studies confirmed the formation of a crystalline mesoporous adsorbent with surface properties which enhanced its usefulness. From the adsorption studies, it was observed that factors such as pH, salts, temperature and contact time influenced the uptake of the anionic dyes. The maximum monolayer capacity of PN-Fe3O4-IDA-Zr for AR was 49.4 mg g−1 (at 313 K) and was well fitted by the Langmuir model with the chemisorption process being the dominant reaction mechanism. In binary systems, PN-Fe3O4-IDA-Zr exhibited higher affinity for AR as compared with AK. The significant removal efficiency exhibited by this novel adsorbent as well as other unique features such as easy retrieval and high regeneration promotes its prospects as an adsorbent for practical wastewater remediation processes.

A Thesis Submitted to the Department Of Chemistry, College of Science and the School Of Graduate ... more A Thesis Submitted to the Department Of Chemistry, College of Science and the School Of Graduate Studies, Kwame Nkrumah University of Science and Technology In Partial Fulfilment of the Requirement for the Award of the Degree of Master of Philosophy (Analytical Chemistry), June-2013

Journal of Cleaner Production, 2021

Environmental Chemistry Letters, 2021

The direct discharge of untreated contaminants into global water systems has jeopardized our wate... more The direct discharge of untreated contaminants into global water systems has jeopardized our water security worldwide. This environmental concern has prompted scientists to develop various methods, systems and agents to remove these pollutants. One such method is adsorption, where adsorbents, such as agricultural waste materials. Compared to commercial carbon, raw agricultural waste material is easily obtained at low cost, but suffers from some drawbacks such as poor adsorptive capability. This can be solved by grafting polyethyleneimine to enhance adsorption. Indeed, polyethyleneimine-functionalized adsorbents have emerged as environmentally safe, cost-effective, and promising adsorbents with high adsorption capabilities in pollutant sequestration. Here we review adsorption using polyethyleneimine-modified agricultural waste materials for pollutant removal. The manuscript outlines the principles of adsorption and proposes methods for the introduction of polyethyleneimine on surface of materials. We present common characterization methods. Kinetics, isotherm and thermodynamic studies are also reviewed. This manuscript also presents the regeneration and reusability potential. Mechanisms involved in adsorption are discussed.

Environmental Science and Pollution Research, 2021

The presence of emerging pollutants such as PO43− and NO3− in water bodies has attracted worldwid... more The presence of emerging pollutants such as PO43− and NO3− in water bodies has attracted worldwide concern about their severe effects on water bodies and the health of humankind in general. Therefore, to preserve the health of humankind and environmental safety, it is of the essence that industrial effluents are treated before they are discharged into water bodies. Amine functionalized walnut shells (ACWNS) were synthesized, characterized, and then tested as a novel adsorbent for PO43− and NO3− removal. The effects of pH, dosage, initial phosphate concentration, interference ions, and temperature on the removal of phosphate and nitrate were investigated. Notably, the adsorption of PO43− and NO3− was exothermic and spontaneous, with a maximum uptake capacity of phosphate and nitrate, at 293 K, 82.2 and 35.7 mg g−1, respectively. The mechanism by which these ions were adsorbed onto ACWNS could be electrostatic interactions and hydrogen bonding. Pseudo-second-order kinetic model fitted the PO43− and NO3− adsorption, while Freundlich and Langmuir models best fitted the PO43− and NO3− adsorption, respectively. Furthermore, in the binary system, the uptake capacity of phosphate decreased by 14.4% while nitrate witnessed a reduction in its uptake capacity of 10.4%. ACWNS has a higher attraction towards both ions and this could be attributed to the existence of a variety of active areas on ACWNS that exhibit a degree of specificity for the individual ions. Results obtained from real water sample analysis confirmed ACWNS as highly efficient to be utilized for practical remediation processes.

Chemosphere, 2022

A biocomposite (PN-Fe3O4-PEI) was synthesized via the chemical modification of peanut husk (a low... more A biocomposite (PN-Fe3O4-PEI) was synthesized via the chemical modification of peanut husk (a low-cost adsorbent) with Fe3O4 particles and polyethyleneimine under benign environmental conditions. The modification agents used in this study were observed to overcome the challenges associated with the use pristine peanut husk with a concomitant enhancement in its efficiency as an adsorbent. Results from the characterization studies employed in this study confirmed PN-Fe3O4-PEI to be a crystalline magnetic adsorbent with a mesoporous structure. The adsorption property of the developed material (PN-Fe3O4-PEI) for wastewater treatment was investigated using Chromium (VI), Phosphates (PO43-) and Congo red (CR) as model pollutants. Using the batch method, PN-Fe3O4-PEI exhibited a maximum monolayer adsorption capacity of 58.4, 13.5 and 71.3 mg g-1 for Cr(VI), PO43- (as P g L-1) and CR, respectively and was dependent on temperature and initial adsorbate concentration. Kinetic studies revealed that the Elovich equation, the pseudo-second order kinetic model and double constant equation well described the uptake of Cr(VI), PO43- and CR onto PN-Fe3O4-PEI, respectively. These results may confirm the uptake of these pollutants to be mainly driven by chemical forces. In addition, PN-Fe3O4-PEI was observed to be efficient for the decontamination of the studied pollutants in real water samples as well as exhibit antibacterial properties towards the growth of S. aureus. These properties of PN-Fe3O4-PEI with its other excellent features such as high stability in solution, good regeneration properties and its facile retrieval from the solution using a magnet promote its suitability for practical wastewater treatment.

Wastewater stemming from industries may contain pollutants such as synthetic dyes and endocrine-d... more Wastewater stemming from industries may contain pollutants such as synthetic dyes and endocrine-disrupting chemicals which are known to be harmful to living organisms. Therefore, to safeguard the wellbeing of humankind and environmental safety, it is imperative for industrial effluents to be sanitized before their discharged into water bodies. Furthermore, to explore the utilization of agricultural byproduct is valuable to study. To achieve this, a Cetyltrimethylammonium bromide functionalized Walnut shells (WNS-CTAB) were prepared to remove pollutants in column approach. The column work was carried out for diverse working conditions. There is in favor of adsorption at low influent pollutant concentration, low flow rate or high bed depth. As the highest breakthrough time of 113 and 23 min at flow rate 6 mL min −1 was recorded for both CR and BPA, respectively, the Yan’s kinetic model best described the breakthrough curve. The adsorbent showed better regeneration capabilities; accord...

Chemosphere, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research Square (Research Square), Jun 16, 2021

The presence of emerging pollutants such as PO4 3and NO3in water bodies has attracted worldwide c... more The presence of emerging pollutants such as PO4 3and NO3in water bodies has attracted worldwide concern about their severe effects on water bodies and the health of humankind in general. Therefore, to preserve the health of humankind and environmental safety, it is of the essence that industrial effluents are treated before they are discharged into water bodies. To accomplish this, the walnut shell was functionalized (ACWNS) with amine for effective removal of PO4 3and NO3-. Characterization studies of ACWNS were conducted using FTIR, XRD, XPS and BET techniques. Removal of both ions was enhanced at lower temperature (293 K). The maximum uptake capacity of phosphate and nitrate, at 293 K, was 82.2 and 35.7 mg g-1 , respectively. The primary mechanism by which these ions were uptaken onto ACWNS could be electrostatic interactions and hydrogen bonding.Pseudosecond-order kinetics fitted the PO4 3̶ and NO3adsorption, while Freundlich and Langmuir models best fitted the PO4 3̶ and NO3 ̶ adsorption, respectively. Furthermore, in the binary system, the uptake capacity of phosphate decreased by 14.4% while nitrate witnessed a reduction in its uptake capacity by 10.4 %. So ACWNS has a higher attraction towards both ions and this could be attributed to the existence of a variety of active areas on ACWNS that exhibit a degree of specificity for the individual anions. Results obtained from real water samples analysis confirmed ACWNS as highly efficient to be utilized for practical remediation processes.

Journal of Colloid and Interface Science, Sep 1, 2021

Accessibility to quality and clean water has in recent times been compromised due to the presence... more Accessibility to quality and clean water has in recent times been compromised due to the presence of pollutants, thus posing as a threat to the survival of living organisms. The adsorption technique in this regard has been observed to be useful in the remediation process with the material used as the adsorbent playing an integral role. In this study, a novel biocomposite (PN-Fe3O4-IDA-Al) based on peanut husk (a low-cost material) was developed by functionalization with aluminum (Al), iminodiacetic acid (IDA) and Fe3O4. The efficiency of PN-Fe3O4-IDA-Al as an adsorbent for the remediation of wastewater was evaluated using Congo red (CR) and phosphates (PO43-) as model pollutants. The results from the characterization studies confirmed PN-Fe3O4-IDA-Al to have superparamagnetic properties which ensures its easy retrieval. Adsorption studies indicated that PN-Fe3O4-IDA-Al had a maximum monolayer capacity of 79.0 ± 2.0 and 16.8 ± 2.5 mg g-1 for CR and PO43- (according to P), respectively, which was significantly dependent on factors such as reaction time, solution pH, temperature and the presence of some common anions. The Freundlich model was observed to better describe both adsorption processes with chemisorption being the principal underlying mechanism. Results from using real water samples confirmed PN-Fe3O4-IDA-Al to be highly efficient for practical remediation processes. These results coupled with the synthesis of PN-Fe3O4-IDA-Al under benign conditions using low-cost materials help to expound the knowledge on the use of low cost materials as the basis for the development of highly efficient adsorbents for wastewater remediation.

Environmental Science and Pollution Research, Jul 23, 2022

Environmental Science and Pollution Research, Apr 26, 2022

We engineered a tiger nut residue (TNR, a low-cost agricultural waste material) through a facile ... more We engineered a tiger nut residue (TNR, a low-cost agricultural waste material) through a facile and simple process to take advantage of the introduced functional groups (cetylpyridinium chloride, CPC) in the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) in batch mode and further investigated its impingement on bacterial growth in a yeast-dextrose broth. The surface characterizations of the adsorbent were achieved through Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller method (BET), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The batch adsorption studies revealed that solution pH, adsorbent dose, temperature, and salt affected the adsorptive capacity of TNR-CPC. The equilibrium data were best fitted by Langmuir isotherm model with a maximum monolayer adsorption capacity of 90.2 mg g–1 at 318 K and pH 3. Pseudo-second-order model best fitted the kinetics data for the adsorption process. Physisorption largely mediated the adsorption system with spontaneity and a shift in entropy of the aqueous solid-solute interface reflecting decreased randomness with an exothermic character. TNR-CPC demonstrated a good reusability potential making it highly economical and compares well with other adsorbents for decontamination of 2,4-D. The adsorption of 2,4-D proceeded through a probable trio-mechanism; electrostatic attraction between the carboxylate anion of 2,4-D and the pyridinium cation of TNR-CPC, hydrogen bonding between the hydroxyl (–OH) group inherent in the TNR and the carboxyl groups in 2,4-D and a triggered π-π stacking between the benzene structures in the adsorbate and the adsorbent. TNR-CPC reported about 99% inhibition rate against both gram-positive S. aureus and gram-negative E. coli. It would be appropriate to investigate the potential of TNR-CPC as a potential replacement to the metal oxides used in wastewater treatment for antibacterial capabilities, and its effects against airborne bacteria could also be of interest.

Environmental Science and Pollution Research, Mar 13, 2021

A novel adsorbent (PN-Fe3O4-IDA-Zr) was developed from the chemical modification of peanut husk (... more A novel adsorbent (PN-Fe3O4-IDA-Zr) was developed from the chemical modification of peanut husk (a low cost material) with Fe3O4, iminodiacetic acid (IDA) and zirconium (Zr) and its efficacy for the sequestration of wastewater assessed using Alizarin red (AR) and Acid chrome blue K (AK) as model pollutants. To elucidate the characteristics of the formed adsorbent, analytical techniques such as the Bruauner-Emmet-Teller (BET) method, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractive spectroscopy (XRD) and vibrating sample magnetometer (VSM) were applied. Results from these studies confirmed the formation of a crystalline mesoporous adsorbent with surface properties which enhanced its usefulness. From the adsorption studies, it was observed that factors such as pH, salts, temperature and contact time influenced the uptake of the anionic dyes. The maximum monolayer capacity of PN-Fe3O4-IDA-Zr for AR was 49.4 mg g−1 (at 313 K) and was well fitted by the Langmuir model with the chemisorption process being the dominant reaction mechanism. In binary systems, PN-Fe3O4-IDA-Zr exhibited higher affinity for AR as compared with AK. The significant removal efficiency exhibited by this novel adsorbent as well as other unique features such as easy retrieval and high regeneration promotes its prospects as an adsorbent for practical wastewater remediation processes.

Colloids and Surfaces A: Physicochemical and Engineering Aspects, Apr 1, 2021

Abstract The development of adsorbents based on agricultural biomass for the remediation of pollu... more Abstract The development of adsorbents based on agricultural biomass for the remediation of polluted waters offers unique benefits and also fits into the concept of green chemistry. In this study, a highly efficient adsorbent (PN-Fe3O4-IDA-Zr) based on peanut husk chemically modified with zirconium, iminodiacetic acid and Fe3O4 was employed for the sequestration of phosphates in synthetic and real water samples. The characterization of PN-Fe3O4-IDA-Zr via analytical techniques confirmed it as a crystalline mesoporous adsorbent with superparamagnetic properties which ensures its easy retrieval from the solution under an external magnetic field. The adsorption capacity and associated mechanisms of the adsorbent were assessed via the batch method. Results from adsorption studies showed the maximum adsorption capacity of PN-Fe3O4-IDA-Zr for PO43− (50 mg L−1, mass as P) to be 13.2 mg g−1 at 313 K and was influenced by factors such as contact time, pH, initial phosphate concentration, salts and temperature. The experimental data were well fitted by the Freundlich model and Elovich equation suggesting the formation of a multilayer on the surface of PN-Fe3O4-IDA-Zr which was mainly influenced by the chemisorption process (mainly via coordination). A comparison of the efficiencies of the adsorbent at its various stages of development shows that the presence of zirconium plays a significant role in the adsorption process thus confirming the design concept of the adsorbent. PN-Fe3O4-IDA-Zr exhibited high stability and efficiency in real water samples that were spiked with high concentrations of phosphates. These results as well as the facile synthetic route for PN-Fe3O4-IDA-Zr under benign conditions promote its prospects as a promising adsorbent for practical applications.

Environmental Science and Pollution Research, Nov 8, 2021

The presence of emerging pollutants such as PO43− and NO3− in water bodies has attracted worldwid... more The presence of emerging pollutants such as PO43− and NO3− in water bodies has attracted worldwide concern about their severe effects on water bodies and the health of humankind in general. Therefore, to preserve the health of humankind and environmental safety, it is of the essence that industrial effluents are treated before they are discharged into water bodies. Amine functionalized walnut shells (ACWNS) were synthesized, characterized, and then tested as a novel adsorbent for PO43− and NO3− removal. The effects of pH, dosage, initial phosphate concentration, interference ions, and temperature on the removal of phosphate and nitrate were investigated. Notably, the adsorption of PO43− and NO3− was exothermic and spontaneous, with a maximum uptake capacity of phosphate and nitrate, at 293 K, 82.2 and 35.7 mg g−1, respectively. The mechanism by which these ions were adsorbed onto ACWNS could be electrostatic interactions and hydrogen bonding. Pseudo-second-order kinetic model fitted the PO43− and NO3− adsorption, while Freundlich and Langmuir models best fitted the PO43− and NO3− adsorption, respectively. Furthermore, in the binary system, the uptake capacity of phosphate decreased by 14.4% while nitrate witnessed a reduction in its uptake capacity of 10.4%. ACWNS has a higher attraction towards both ions and this could be attributed to the existence of a variety of active areas on ACWNS that exhibit a degree of specificity for the individual ions. Results obtained from real water sample analysis confirmed ACWNS as highly efficient to be utilized for practical remediation processes.

Chemosphere, 2022

A biocomposite (PN-Fe3O4-PEI) was synthesized via the chemical modification of peanut husk (a low... more A biocomposite (PN-Fe3O4-PEI) was synthesized via the chemical modification of peanut husk (a low-cost adsorbent) with Fe3O4 particles and polyethyleneimine under benign environmental conditions. The modification agents used in this study were observed to overcome the challenges associated with the use pristine peanut husk with a concomitant enhancement in its efficiency as an adsorbent. Results from the characterization studies employed in this study confirmed PN-Fe3O4-PEI to be a crystalline magnetic adsorbent with a mesoporous structure. The adsorption property of the developed material (PN-Fe3O4-PEI) for wastewater treatment was investigated using Chromium (VI), Phosphates (PO43-) and Congo red (CR) as model pollutants. Using the batch method, PN-Fe3O4-PEI exhibited a maximum monolayer adsorption capacity of 58.4, 13.5 and 71.3 mg g-1 for Cr(VI), PO43- (as P g L-1) and CR, respectively and was dependent on temperature and initial adsorbate concentration. Kinetic studies revealed that the Elovich equation, the pseudo-second order kinetic model and double constant equation well described the uptake of Cr(VI), PO43- and CR onto PN-Fe3O4-PEI, respectively. These results may confirm the uptake of these pollutants to be mainly driven by chemical forces. In addition, PN-Fe3O4-PEI was observed to be efficient for the decontamination of the studied pollutants in real water samples as well as exhibit antibacterial properties towards the growth of S. aureus. These properties of PN-Fe3O4-PEI with its other excellent features such as high stability in solution, good regeneration properties and its facile retrieval from the solution using a magnet promote its suitability for practical wastewater treatment.

Chinese Journal of Chemical Engineering, Aug 1, 2023

Chinese Journal of Chemical Engineering

Environmental Science and Pollution Research

We engineered a tiger nut residue (TNR, a low-cost agricultural waste material) through a facile ... more We engineered a tiger nut residue (TNR, a low-cost agricultural waste material) through a facile and simple process to take advantage of the introduced functional groups (cetylpyridinium chloride, CPC) in the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) in batch mode and further investigated its impingement on bacterial growth in a yeast-dextrose broth. The surface characterizations of the adsorbent were achieved through Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller method (BET), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The batch adsorption studies revealed that solution pH, adsorbent dose, temperature, and salt affected the adsorptive capacity of TNR-CPC. The equilibrium data were best fitted by Langmuir isotherm model with a maximum monolayer adsorption capacity of 90.2 mg g–1 at 318 K and pH 3. Pseudo-second-order model best fitted the kinetics data for the adsorption process. Physisorption largely mediated the adsorption system with spontaneity and a shift in entropy of the aqueous solid-solute interface reflecting decreased randomness with an exothermic character. TNR-CPC demonstrated a good reusability potential making it highly economical and compares well with other adsorbents for decontamination of 2,4-D. The adsorption of 2,4-D proceeded through a probable trio-mechanism; electrostatic attraction between the carboxylate anion of 2,4-D and the pyridinium cation of TNR-CPC, hydrogen bonding between the hydroxyl (–OH) group inherent in the TNR and the carboxyl groups in 2,4-D and a triggered π-π stacking between the benzene structures in the adsorbate and the adsorbent. TNR-CPC reported about 99% inhibition rate against both gram-positive S. aureus and gram-negative E. coli. It would be appropriate to investigate the potential of TNR-CPC as a potential replacement to the metal oxides used in wastewater treatment for antibacterial capabilities, and its effects against airborne bacteria could also be of interest.

Journal of Environmental Chemical Engineering, 2022

Environmental Science and Pollution Research, 2021

A novel adsorbent (PN-Fe3O4-IDA-Zr) was developed from the chemical modification of peanut husk (... more A novel adsorbent (PN-Fe3O4-IDA-Zr) was developed from the chemical modification of peanut husk (a low cost material) with Fe3O4, iminodiacetic acid (IDA) and zirconium (Zr) and its efficacy for the sequestration of wastewater assessed using Alizarin red (AR) and Acid chrome blue K (AK) as model pollutants. To elucidate the characteristics of the formed adsorbent, analytical techniques such as the Bruauner-Emmet-Teller (BET) method, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractive spectroscopy (XRD) and vibrating sample magnetometer (VSM) were applied. Results from these studies confirmed the formation of a crystalline mesoporous adsorbent with surface properties which enhanced its usefulness. From the adsorption studies, it was observed that factors such as pH, salts, temperature and contact time influenced the uptake of the anionic dyes. The maximum monolayer capacity of PN-Fe3O4-IDA-Zr for AR was 49.4 mg g−1 (at 313 K) and was well fitted by the Langmuir model with the chemisorption process being the dominant reaction mechanism. In binary systems, PN-Fe3O4-IDA-Zr exhibited higher affinity for AR as compared with AK. The significant removal efficiency exhibited by this novel adsorbent as well as other unique features such as easy retrieval and high regeneration promotes its prospects as an adsorbent for practical wastewater remediation processes.

A Thesis Submitted to the Department Of Chemistry, College of Science and the School Of Graduate ... more A Thesis Submitted to the Department Of Chemistry, College of Science and the School Of Graduate Studies, Kwame Nkrumah University of Science and Technology In Partial Fulfilment of the Requirement for the Award of the Degree of Master of Philosophy (Analytical Chemistry), June-2013

Journal of Cleaner Production, 2021

Environmental Chemistry Letters, 2021

The direct discharge of untreated contaminants into global water systems has jeopardized our wate... more The direct discharge of untreated contaminants into global water systems has jeopardized our water security worldwide. This environmental concern has prompted scientists to develop various methods, systems and agents to remove these pollutants. One such method is adsorption, where adsorbents, such as agricultural waste materials. Compared to commercial carbon, raw agricultural waste material is easily obtained at low cost, but suffers from some drawbacks such as poor adsorptive capability. This can be solved by grafting polyethyleneimine to enhance adsorption. Indeed, polyethyleneimine-functionalized adsorbents have emerged as environmentally safe, cost-effective, and promising adsorbents with high adsorption capabilities in pollutant sequestration. Here we review adsorption using polyethyleneimine-modified agricultural waste materials for pollutant removal. The manuscript outlines the principles of adsorption and proposes methods for the introduction of polyethyleneimine on surface of materials. We present common characterization methods. Kinetics, isotherm and thermodynamic studies are also reviewed. This manuscript also presents the regeneration and reusability potential. Mechanisms involved in adsorption are discussed.

Environmental Science and Pollution Research, 2021

The presence of emerging pollutants such as PO43− and NO3− in water bodies has attracted worldwid... more The presence of emerging pollutants such as PO43− and NO3− in water bodies has attracted worldwide concern about their severe effects on water bodies and the health of humankind in general. Therefore, to preserve the health of humankind and environmental safety, it is of the essence that industrial effluents are treated before they are discharged into water bodies. Amine functionalized walnut shells (ACWNS) were synthesized, characterized, and then tested as a novel adsorbent for PO43− and NO3− removal. The effects of pH, dosage, initial phosphate concentration, interference ions, and temperature on the removal of phosphate and nitrate were investigated. Notably, the adsorption of PO43− and NO3− was exothermic and spontaneous, with a maximum uptake capacity of phosphate and nitrate, at 293 K, 82.2 and 35.7 mg g−1, respectively. The mechanism by which these ions were adsorbed onto ACWNS could be electrostatic interactions and hydrogen bonding. Pseudo-second-order kinetic model fitted the PO43− and NO3− adsorption, while Freundlich and Langmuir models best fitted the PO43− and NO3− adsorption, respectively. Furthermore, in the binary system, the uptake capacity of phosphate decreased by 14.4% while nitrate witnessed a reduction in its uptake capacity of 10.4%. ACWNS has a higher attraction towards both ions and this could be attributed to the existence of a variety of active areas on ACWNS that exhibit a degree of specificity for the individual ions. Results obtained from real water sample analysis confirmed ACWNS as highly efficient to be utilized for practical remediation processes.

Chemosphere, 2022

A biocomposite (PN-Fe3O4-PEI) was synthesized via the chemical modification of peanut husk (a low... more A biocomposite (PN-Fe3O4-PEI) was synthesized via the chemical modification of peanut husk (a low-cost adsorbent) with Fe3O4 particles and polyethyleneimine under benign environmental conditions. The modification agents used in this study were observed to overcome the challenges associated with the use pristine peanut husk with a concomitant enhancement in its efficiency as an adsorbent. Results from the characterization studies employed in this study confirmed PN-Fe3O4-PEI to be a crystalline magnetic adsorbent with a mesoporous structure. The adsorption property of the developed material (PN-Fe3O4-PEI) for wastewater treatment was investigated using Chromium (VI), Phosphates (PO43-) and Congo red (CR) as model pollutants. Using the batch method, PN-Fe3O4-PEI exhibited a maximum monolayer adsorption capacity of 58.4, 13.5 and 71.3 mg g-1 for Cr(VI), PO43- (as P g L-1) and CR, respectively and was dependent on temperature and initial adsorbate concentration. Kinetic studies revealed that the Elovich equation, the pseudo-second order kinetic model and double constant equation well described the uptake of Cr(VI), PO43- and CR onto PN-Fe3O4-PEI, respectively. These results may confirm the uptake of these pollutants to be mainly driven by chemical forces. In addition, PN-Fe3O4-PEI was observed to be efficient for the decontamination of the studied pollutants in real water samples as well as exhibit antibacterial properties towards the growth of S. aureus. These properties of PN-Fe3O4-PEI with its other excellent features such as high stability in solution, good regeneration properties and its facile retrieval from the solution using a magnet promote its suitability for practical wastewater treatment.

Wastewater stemming from industries may contain pollutants such as synthetic dyes and endocrine-d... more Wastewater stemming from industries may contain pollutants such as synthetic dyes and endocrine-disrupting chemicals which are known to be harmful to living organisms. Therefore, to safeguard the wellbeing of humankind and environmental safety, it is imperative for industrial effluents to be sanitized before their discharged into water bodies. Furthermore, to explore the utilization of agricultural byproduct is valuable to study. To achieve this, a Cetyltrimethylammonium bromide functionalized Walnut shells (WNS-CTAB) were prepared to remove pollutants in column approach. The column work was carried out for diverse working conditions. There is in favor of adsorption at low influent pollutant concentration, low flow rate or high bed depth. As the highest breakthrough time of 113 and 23 min at flow rate 6 mL min −1 was recorded for both CR and BPA, respectively, the Yan’s kinetic model best described the breakthrough curve. The adsorbent showed better regeneration capabilities; accord...

Chemosphere, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.