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Nyamato GS. Perspectives and prospects of chelation extraction of heavy metals from wastewater: A review. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2023; 88:47-61. [PMID: 37452533 PMCID: wst_2023_182 DOI: 10.2166/wst.2023.182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Heavy metals' contamination of water resources is a global environmental issue due to their detrimental effects on human health. To safeguard humans and the environment, toxic heavy metals must be removed from contaminated water because they cannot be broken down. Diverse technologies are employed to reduce the levels of heavy metals in wastewater. However, these technologies suffer from being either costly or ineffective, particularly when the effluent has extremely low residual amounts. This review outlines the main accomplishments and promising future directions for solvent extraction as one of the potential methods of extracting heavy metals from water, utilizing literature reports. In addition to reviewing some of the commercial chelating reagents now in use, this article also discusses some of the obnoxious effects on human health that are associated with exposure to heavy metals.
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Affiliation(s)
- George Simba Nyamato
- Department of Physical Sciences, University of Embu, P.O. Box 6-60100, Embu, Kenya E-mail:
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Coordination behavior and binding properties of 2,6-pyridinedimethanol with Cu(II), Zn(II), and Cd(II) cations. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.121042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Nyamato GS, Wambugu K, Kiratu J, Ojwach SO. Liquid-liquid extraction of copper(II), zinc(II), cadmium(II), and lead(II) from aqueous solution and sewage effluent using phenoxy-amino ligands. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 85:2993-3001. [PMID: 35638801 DOI: 10.2166/wst.2022.164] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The phenoxy-amino ligands 2-(((2-(diethylamino)ethyl)amino)methyl)phenol (L1) and 2-(((2-mercaptoethyl)amino)methyl)-phenol (L2) were studied as model chelating agents for liquid-liquid extraction of copper(II), zinc(II), cadmium(II), and lead(II) cations from water using dichloromethane-water biphasic system. The relative affinities of these chelating ligands for copper(II), zinc(II), cadmium(II), and lead(II) by liquid-liquid extraction were found to be in the order copper(II)> zinc(II) > cadmium(II) > lead(II). The ligands L1 and L2 showed binding efficiencies ranging from 78%-97% for copper(II), 75%-91% for zinc(II), 76%-92% for cadmium(II), and 59%-67% for lead(II). The extraction protocol was successfully applied to sewage effluent.
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Affiliation(s)
- George S Nyamato
- Department of Physical Sciences, University of Embu, P.O Box 6-60100, Embu, Kenya E-mail:
| | - Kelvin Wambugu
- Department of Physical Sciences, University of Embu, P.O Box 6-60100, Embu, Kenya E-mail:
| | - John Kiratu
- Department of Physical Sciences, University of Embu, P.O Box 6-60100, Embu, Kenya E-mail:
| | - Stephen O Ojwach
- School of Chemistry and Physics, University of KwaZulu-Natal, Scottsville, South Africa
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Wambugu K, Nyamato GS, Ogunah J, Ojwach SO. Phenoxy-imino ligands: coordination chemistry and binding properties with copper(II) cations. J COORD CHEM 2021. [DOI: 10.1080/00958972.2021.2015581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Kelvin Wambugu
- Department of Physical Sciences, University of Embu, Embu, Kenya
| | | | - Joanne Ogunah
- Department of Physical Sciences, University of Embu, Embu, Kenya
| | - Stephen O. Ojwach
- School of Chemistry and Physics, University of KwaZulu-Natal, Scottsville, South Africa
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New Bis-Pyrazole-Bis-Acetate Based Coordination Complexes: Influence of Counter-Anions and Metal Ions on the Supramolecular Structures. SUSTAINABILITY 2020. [DOI: 10.3390/su13010288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A new flexible bis-pyrazol-bis-acetate ligand, diethyl 2,2’-(pyridine-2,6-diylbis (5-methyl-1H-pyrazole-3,1-diyl))diacetate (L), has been synthesised, and three coordination complexes, namely, [Zn(L)2](BF4)2 (1), [MnLCl2] (2) and [CdLCl2] (3) have been obtained. All ligands and complexes were characterised by IR, mass spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. Single crystal X-ray diffraction experiment revealed that the primary supramolecular building block of 1 is a hexagonal chair shaped 0D hydrogen bonded synthon (stabilised by C–H∙∙∙O hydrogen bonding and C=O∙∙∙π interactions), which further built into a 2D corrugated sheet-like architecture having a 3-c net honeycomb topology, and finally extended to a 3D hydrogen bonded network structure having a five nodal 1,3,3,3,7-c net, through C–H∙∙∙F interactions. On the other hand, the two crystallographically independent molecules of 2 exhibited two distinct supramolecular structures such as 2D hydrogen bonded sheet structure and 1D zigzag hydrogen bonded chain, sustained by C–H∙O and C–H∙∙∙Cl interactions, which are further self-assembled into a 3,4-c network structure, and 3 showed a 2D hydrogen bonded sheet structure. The supramolecular structural diversity in these complexes is due to the different conformations adopted by the ligands, which are mainly induced by different metal ions with coordination environments controlled by different anions. Hirshfeld surface analysis was explored for the qualitative and quantitative analysis of the supramolecular interactions.
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Matiwane A, Obuah C, Darkwa J. (Pyrazolylethyl-amine)zinc(II) carboxylate complexes as catalysts for the copolymerization of CO2 and cyclohexene oxide. Polyhedron 2020. [DOI: 10.1016/j.poly.2020.114767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nallasamy P, Senthilkumar K, Mohan G, Moon ILS. Structural and luminescent properties of a tetranuclear cage-type cadmium(II) carboxylate cluster containing a V-shaped water trimer. J COORD CHEM 2016. [DOI: 10.1080/00958972.2016.1156097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Palanisami Nallasamy
- Department of Chemical Engineering, Sunchon National University, Suncheon, South Korea
| | - Kabali Senthilkumar
- Materials Chemistry Division, School of Advanced Sciences, VIT University, Vellore, India
| | | | - IL-Shik Moon
- Department of Chemical Engineering, Sunchon National University, Suncheon, South Korea
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Zikode M, Ojwach SO, Akerman MP. Bis(pyrazolylmethyl)pyridine Zn(II) and Cu(II) complexes: Molecular structures and kinetic studies of ring-opening polymerization of ε-caprolactone. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molcata.2015.12.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Obuah C, Lochee Y, Jordaan JH, Otto DP, Nyokong T, Darkwa J. (Ferrocenylpyrazolyl)zinc(II) benzoates as catalysts for the ring opening polymerization of ε-caprolactone. Polyhedron 2015. [DOI: 10.1016/j.poly.2015.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ojwach SO, Okemwa TT, Attandoh NW, Omondi B. Structural and kinetic studies of the polymerization reactions of ε-caprolactone catalyzed by (pyrazol-1-ylmethyl)pyridine Cu(II) and Zn(II) complexes. Dalton Trans 2013; 42:10735-45. [PMID: 23774962 DOI: 10.1039/c3dt51338f] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structural and kinetic studies of polymerization reactions of ε-caprolactone (ε-CL) using (pyrazolylmethyl)pyridine Cu(II) and Zn(II) complexes as initiators is described. Reactions of 2-(3,5-dimethylpyrazol-1-ylmethyl)pyridine (L1) and 2-(3,5-diphenylpyrazol-1-ylmethyl)pyridine (L2) with Zn(Ac)2·2H2O or Cu(Ac)2·2H2O produced the corresponding complexes [Zn(Ac)2(L1)] (1), [Cu(Ac)2(L1)] (2), [Zn(Ac)2(L2)] (3) and [Cu2(Ac)4(L2)2] (4) respectively. Solid state structures of 1 and 4 confirmed that complexes 1 and 4 are monomeric and dimeric respectively and that L1 is bidentate in 1 while L2 is monodentate in 4. X-band EPR spectra of 2 and 4 revealed that complex 2 is monomeric both in solid and solution state, while the paddle-wheel structure of 4 is retained in solution. Complexes 1-4 formed active initiators in the ring opening polymerization of ε-CL. Zn(II) complexes 1 and 3 exhibited higher rate constants of 0.044 h(-1) and 0.096 h(-1) respectively compared to rate constants of 0.017 h(-1) and 0.031 h(-1) observed for the corresponding Cu(II) complexes 2 and 4 respectively at 110 °C. All the polymerization reactions follow pseudo first-order kinetic with respect to ε-CL monomer. Initiator 1 showed first-order dependency on the polymerization reactions and utilizes only one active site as the initiating group. The molecular weights of the polymers produced range from 1982 g mol(-1) to 14,568 g mol(-1) and exhibited relatively broad molecular weight distributions associated with transesterification reactions.
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Affiliation(s)
- Stephen O Ojwach
- School of Chemistry and Physics, University of KwaZulu-Natal, Pietermaritzburg Campus, Private Bag X01 Scottsville, 3209, South Africa.
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Affiliation(s)
- Wail Al Zoubi
- a Faculty of Science, Department of Chemistry , University of Damascus , Damascus , Syria
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Njoroge MW, Ojwach SO, Nyamato GS, Omondi B, Darkwa J. Coordination behavior and binding properties of (3,5-dimethyl- 1H-pyrazol-1-yl)ethanol with Cu(II), Zn(II), Cd(II), and Pb(II) metals. J COORD CHEM 2013. [DOI: 10.1080/00958972.2013.784904] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
| | - Stephen O. Ojwach
- b School of Chemistry and Physics, University of KwaZulu-Natal , Scottsville , South Africa
| | - George S. Nyamato
- b School of Chemistry and Physics, University of KwaZulu-Natal , Scottsville , South Africa
| | - Bernard Omondi
- c School of Chemistry and Physics, University of KwaZulu-Natal , Durban , South Africa
| | - James Darkwa
- d Department of Chemistry , University of Johannesburg , Auckland Park , South Africa
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Omran OA, Antipin IS. Synthesis of tetrathioesters and tetrathioamides based p-tert-butylthiacalix[4]arene and studying their recognition abilities towards different metals by extraction. J INCL PHENOM MACRO 2013. [DOI: 10.1007/s10847-012-0278-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Ojwach SO, Nyamato GS, Omondi B, Darkwa J. Chelating (pyrazolylmethyl)pyridine ligands: Coordination chemistry and binding properties with zinc(II) and cadmium(II) cations. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2012.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Solid-state detection of gases by use of thin films based on pyrazole units, and morphological characterization of the films by AFM. RESEARCH ON CHEMICAL INTERMEDIATES 2012. [DOI: 10.1007/s11164-012-0541-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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