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Environmental problems - Chemical approaches
RESEARCH ARTICLE

Metal ion binding by humic substances as emergent functions of labile supramolecular assemblies

Elena A. Vialykh https://orcid.org/0000-0001-7351-6567 A E , Dennis R. Salahub B C and Gopal Achari D
+ Author Affiliations
- Author Affiliations

A Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.

B Department of Chemistry, Centre for Molecular Simulation (CMS), Institute for Quantum Science and Technology and Quantum Alberta (IQST), University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.

C College of Chemistry and Chemical Engineering, Henan University of Technology, 100 Lian Hua Street, High-Tech Development Zone, Zhengzhou 450001, China.

D Schulich School of Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.

E Corresponding author. Email: elena.vialykh@ucalgary.ca

Environmental Chemistry 17(3) 252-265 https://doi.org/10.1071/EN19198
Submitted: 8 January 2019  Accepted: 19 August 2019   Published: 1 October 2019

Environmental context. The fundamental basis for the high flexibility of humic substances is still unclear, though it is crucial for the understanding of metal bioavailability and toxicity in soil and aqueous environments. We show at the molecular level how characteristics of organic matter affect metal binding depending on the environmental conditions. Such understanding will help in the modulation of metal availability in soil and water in changing environmental situations.

Abstract. In this work, we explore the hypothesis that humic substances (HS) can be perceived as labile supramolecular assemblages, the functioning of which is mainly determined by chemical composition and characteristics, the size of molecular units and weak intermolecular forces, rather than the exact primary structure of molecular moieties and their spatial configuration. To test the hypothesis, 72 computational models of three different organic mixtures were composed. The formation of inner and outer sphere metal–ligand complexes, metal binding sites, complex configurations, binding energies and aggregation/dissolution as emergent properties of HS were determined under various conditions. The results of computational modelling revealed that: (i) the highest Cu2+ binding (55.6 %) was by the SRFA-22 organic model, which represents low-molecular-weight fulvic acids. In contrast, the highest amount of inner-sphere Mg–organic matter complex (63.4 %) was formed in SRHA-6, which has higher-molecular-weight constituents. Therefore, a correlation between the type of cation, the system aromaticity and the extent of metal complexation is proposed. (ii) Increase of metal ion concentration and decrease of water content resulted in an increase in the number of hydrogen bonds and more compact and stable aggregates with lower hydrophilic and higher hydrophobic surface areas in SRFA-22. However, in SRHA-6, the results varied owing to the competition between metal binding, H-bonding and non-polar interactions in the structural arrangement of the aggregates. In general, the aggregation process, driven by metal complexation and water removal, resulted in the formation of more stable conformers, with lower potential energy, with the only exception of SRHA-6–Cu.


References

Alberts JJ, Filip Z (1998). Metal binding in estuarine humic and fulvic acids: FTIR analysis of humic acid–metal complexes. Environmental Technology 19, 923–931.
Metal binding in estuarine humic and fulvic acids: FTIR analysis of humic acid–metal complexesCrossref | GoogleScholarGoogle Scholar |

Alcacio TE, Hesterberg D, Chou JW, Martin JD, Beauchemin S, Sayers DE (2001). Molecular scale characteristics of Cu(II) bonding in goethite–humate complexes. Geochimica et Cosmochimica Acta 65, 1355–1366.
Molecular scale characteristics of Cu(II) bonding in goethite–humate complexesCrossref | GoogleScholarGoogle Scholar |

Alvarez-Puebla RA, Valenzuela-Calahorro C, Garrido JJ (2004). Retention of Co(II), Ni(II), and Cu(II) on a purified brown humic acid. Modeling and characterization of the sorption process. Langmuir 20, 3657–3664.
Retention of Co(II), Ni(II), and Cu(II) on a purified brown humic acid. Modeling and characterization of the sorption processCrossref | GoogleScholarGoogle Scholar | 15875396PubMed |

Aquino AJA, Tunega D, Schaumann GE, Haberhauer G, Gerzabek MH, Lischka H (2011). The functionality of cation bridges for binding polar groups in soil aggregates. International Journal of Quantum Chemistry 111, 1531–1542.
The functionality of cation bridges for binding polar groups in soil aggregatesCrossref | GoogleScholarGoogle Scholar |

Aquino AJA, Tunega D, Schaumann GE, Haberhauer G, Gerzabek MH, Lischka H (2014). Proton transfer processes in polar regions of humic substances initiated by aqueous aluminum cation bridges: a computational study. Geoderma 213, 115–123.
Proton transfer processes in polar regions of humic substances initiated by aqueous aluminum cation bridges: a computational studyCrossref | GoogleScholarGoogle Scholar |

Aung NN, Nakajima F, Furumai H (2008). Trace metal speciation during dry and wet weather flows in the Tama River, Japan, by using diffusive gradients in thin films (DGT). Journal of Environmental Monitoring 10, 219–230.
Trace metal speciation during dry and wet weather flows in the Tama River, Japan, by using diffusive gradients in thin films (DGT)Crossref | GoogleScholarGoogle Scholar |

Baalousha M, Motelica-Heino M, Coustumer PL (2006). Conformation and size of humic substances: effects of major cation concentration and type, pH, salinity, and residence time. Colloids and Surfaces A: Physicochemical and Engineering Aspects 272, 48–55.
Conformation and size of humic substances: effects of major cation concentration and type, pH, salinity, and residence timeCrossref | GoogleScholarGoogle Scholar |

Baca SG, Reetz MT, Goddard R, Filippova IG, Simonov YA, Gdaniec M, Gerbeleu N (2006). Coordination polymers constructed from o-phthalic acid and diamines: syntheses and crystal structures of the phthalate-imidazole complexes {[Cu(Pht)(Im)2]·1.5H2O}n and [Co(Pht)(Im)2]n and their application in oxidation catalysis. Polyhedron 25, 1215–1222.
Coordination polymers constructed from o-phthalic acid and diamines: syntheses and crystal structures of the phthalate-imidazole complexes {[Cu(Pht)(Im)2]·1.5H2O}n and [Co(Pht)(Im)2]n and their application in oxidation catalysisCrossref | GoogleScholarGoogle Scholar |

Bertoli AC, Garcia JS, Trevisan MG, Ramalho TC, Freitas MP (2016). Interactions fulvate–metal (Zn2+, Cu2+ and Fe2+): theoretical investigation of thermodynamic, structural and spectroscopic properties. Biometals 29, 275–285.
Interactions fulvate–metal (Zn2+, Cu2+ and Fe2+): theoretical investigation of thermodynamic, structural and spectroscopic propertiesCrossref | GoogleScholarGoogle Scholar | 26857737PubMed |

Bloom PR, McBride MB (1979). Metal ion binding and exchange with hydrogen ions in acid-washed peat 1. Soil Science Society of America Journal 43, 687–692.
Metal ion binding and exchange with hydrogen ions in acid-washed peat 1Crossref | GoogleScholarGoogle Scholar |

Boyd SA, Sommers LE, Nelson DW, West DX (1981). The mechanism of copper(II) binding by humic acid: an electron spin resonance study of a copper(II)–humic acid complex and some adducts with nitrogen donors 1. Soil Science Society of America Journal 45, 745–749.
The mechanism of copper(II) binding by humic acid: an electron spin resonance study of a copper(II)–humic acid complex and some adducts with nitrogen donors 1Crossref | GoogleScholarGoogle Scholar |

Bresnahan WT, Grant CL, Weber JH (1978). Stability constants for the complexation of copper(II) ions with water and soil fulvic acids measured by an ion-selective electrode. Analytical Chemistry 50, 1675–1679.
Stability constants for the complexation of copper(II) ions with water and soil fulvic acids measured by an ion-selective electrodeCrossref | GoogleScholarGoogle Scholar |

Cabaniss S (2008). ‘Proceedings of the 14th International Meeting of the International Humic Substances Society’, pp. 3–6. (IHSS: Moscow)

Cabaniss SE (2011). Forward modeling of metal complexation by NOM: II. Prediction of binding site properties. Environmental Science & Technology 45, 3202–3209.
Forward modeling of metal complexation by NOM: II. Prediction of binding site propertiesCrossref | GoogleScholarGoogle Scholar |

Cao D, Huang H, Hu M, Cui L, Geng F, Rao Z, Niu H, Cai Y, Kang Y (2015). Comprehensive characterization of natural organic matter by MALDI- and ESI-Fourier-transform ion cyclotron resonance mass spectrometry. Analytica Chimica Acta 866, 48–58.
Comprehensive characterization of natural organic matter by MALDI- and ESI-Fourier-transform ion cyclotron resonance mass spectrometryCrossref | GoogleScholarGoogle Scholar | 25732692PubMed |

Christl I, Metzger A, Heidmann I, Kretzschmar R (2005). Effect of humic and fulvic acid concentrations and ionic strength on copper and lead binding. Environmental Science & Technology 39, 5319–5326.
Effect of humic and fulvic acid concentrations and ionic strength on copper and lead bindingCrossref | GoogleScholarGoogle Scholar |

Corbett PT, Leclaire J, Vial L, West KR, Wietor JL, Sanders JKM, Otto S (2006). Dynamic combinatorial chemistry. Chemical Reviews 106, 3652–3711.
Dynamic combinatorial chemistryCrossref | GoogleScholarGoogle Scholar | 16967917PubMed |

Croué JP, Benedetti MF, Violleau D, Leenheer JA (2003). Characterization and copper binding of humic and non-humic organic matter isolated from the South Platte River: evidence for the presence of nitrogenous binding site. Environmental Science & Technology 37, 328–336.
Characterization and copper binding of humic and non-humic organic matter isolated from the South Platte River: evidence for the presence of nitrogenous binding siteCrossref | GoogleScholarGoogle Scholar |

D’Angelo P, Bottari E, Festa MR, Nolting HF, Pavel NV (1998). X-ray absorption study of copper(II)–glycinate complexes in aqueous solution. The Journal of Physical Chemistry B 102, 3114–3122.
X-ray absorption study of copper(II)–glycinate complexes in aqueous solutionCrossref | GoogleScholarGoogle Scholar |

Frenkel AI, Korshin GV, Ankudinov AL (2000). XANES study of Cu2+-binding sites in aquatic humic substances. Environmental Science & Technology 34, 2138–2142.
XANES study of Cu2+-binding sites in aquatic humic substancesCrossref | GoogleScholarGoogle Scholar |

Fulda B, Voegelin A, Maurer F, Christl I, Kretzschmar R (2013). Copper redox transformation and complexation by reduced and oxidized soil humic acid. 1. X-ray absorption spectroscopy study. Environmental Science & Technology 47, 10903–10911.
Copper redox transformation and complexation by reduced and oxidized soil humic acid. 1. X-ray absorption spectroscopy studyCrossref | GoogleScholarGoogle Scholar |

Ghosh K, Schnitzer M (1980). Macromolecular structures of humic substances. Soil Science 129, 266–276.
Macromolecular structures of humic substancesCrossref | GoogleScholarGoogle Scholar |

Gondar D, Iglesias A, López R, Fiol S, Antelo JM, Arce F (2006). Copper binding by peat fulvic and humic acids extracted from two horizons of an ombrotrophic peat bog. Chemosphere 63, 82–88.
Copper binding by peat fulvic and humic acids extracted from two horizons of an ombrotrophic peat bogCrossref | GoogleScholarGoogle Scholar | 16146645PubMed |

Hertkorn N, Frommberger M, Witt M, Koch BP, Schmitt-Kopplin P, Perdue EM (2008). Natural organic matter and the event horizon of mass spectrometry. Analytical Chemistry 80, 8908–8919.
Natural organic matter and the event horizon of mass spectrometryCrossref | GoogleScholarGoogle Scholar | 19551926PubMed |

Ho TL (1975). Hard soft acids bases (HSAB) principle and organic chemistry. Chemical Reviews 75, 1–20.
Hard soft acids bases (HSAB) principle and organic chemistryCrossref | GoogleScholarGoogle Scholar |

Ikeya K, Sleighter RL, Hatcher PG, Watanabe A (2015). Characterization of the chemical composition of soil humic acids using Fourier-transform ion cyclotron resonance mass spectrometry. Geochimica et Cosmochimica Acta 153, 169–182.
Characterization of the chemical composition of soil humic acids using Fourier-transform ion cyclotron resonance mass spectrometryCrossref | GoogleScholarGoogle Scholar |

Kalinichev AG, Kirkpatrick RJ (2007). Molecular dynamics simulation of cationic complexation with natural organic matter. European Journal of Soil Science 58, 909–917.
Molecular dynamics simulation of cationic complexation with natural organic matterCrossref | GoogleScholarGoogle Scholar |

Karlsson T, Persson P, Skyllberg U (2006). Complexation of copper(II) in organic soils and in dissolved organic matter – EXAFS evidence for chelate ring structures. Environmental Science & Technology 40, 2623–2628.
Complexation of copper(II) in organic soils and in dissolved organic matter – EXAFS evidence for chelate ring structuresCrossref | GoogleScholarGoogle Scholar |

Korshin GV, Frenkel AI, Stern EA (1998). EXAFS study of the inner shell structure in copper(II) complexes with humic substances. Environmental Science & Technology 32, 2699–2705.
EXAFS study of the inner shell structure in copper(II) complexes with humic substancesCrossref | GoogleScholarGoogle Scholar |

Linder PW, Murray K (1987). Statistical determination of the molecular structure and the metal binding sites of fulvic acids. Science of The Total Environment 64, 149–161.
Statistical determination of the molecular structure and the metal binding sites of fulvic acidsCrossref | GoogleScholarGoogle Scholar |

Manceau A, Matynia A (2010). The nature of Cu bonding to natural organic matter. Geochimica et Cosmochimica Acta 74, 2556–2580.
The nature of Cu bonding to natural organic matterCrossref | GoogleScholarGoogle Scholar |

McBride MB (1978). Transition metal bonding in humic acid: an ESR study. Soil Science 126, 200–209.
Transition metal bonding in humic acid: an ESR studyCrossref | GoogleScholarGoogle Scholar |

Monti S, Corozzi A, Fristrup P, Joshi KL, Shin YK, Oelschlaeger P, van Duin ACT, Barone V (2013). Exploring the conformational and reactive dynamics of biomolecules in solution using an extended version of the glycine reactive force field. Physical Chemistry Chemical Physics 15, 15062–15077.
Exploring the conformational and reactive dynamics of biomolecules in solution using an extended version of the glycine reactive force fieldCrossref | GoogleScholarGoogle Scholar | 23925839PubMed |

Pavlov M, Siegbahn PE, Sandström M (1998). Hydration of beryllium, magnesium, calcium, and zinc ions using density functional theory. The Journal of Physical Chemistry A 102, 219–228.
Hydration of beryllium, magnesium, calcium, and zinc ions using density functional theoryCrossref | GoogleScholarGoogle Scholar |

Piccolo A (2002). The supramolecular structure of humic substances: A novel understanding of humus chemistry and implications in soil science. Advances in Agronomy 75, 57–134.
The supramolecular structure of humic substances: A novel understanding of humus chemistry and implications in soil scienceCrossref | GoogleScholarGoogle Scholar |

Piotrowicz SR, Harvey GR, Boran DA, Weisel CP, Springer-Young M (1984). Cadmium, copper, and zinc interactions with marine humus as a function of ligand structure. Marine Chemistry 14, 333–346.
Cadmium, copper, and zinc interactions with marine humus as a function of ligand structureCrossref | GoogleScholarGoogle Scholar |

Reemtsma T, These A, Springer A, Linscheid M (2008). Differences in the molecular composition of fulvic acid size fractions detected by size-exclusion chromatography–online Fourier-transform ion cyclotron resonance (FTICR) mass spectrometry. Water Research 42, 63–72.
Differences in the molecular composition of fulvic acid size fractions detected by size-exclusion chromatography–online Fourier-transform ion cyclotron resonance (FTICR) mass spectrometryCrossref | GoogleScholarGoogle Scholar | 17640699PubMed |

Schaumann GE, Thiele-Bruhn S (2011). Molecular modeling of soil organic matter: squaring the circle?. Geoderma 166, 1–14.
Molecular modeling of soil organic matter: squaring the circle?Crossref | GoogleScholarGoogle Scholar |

Scheel T, Haumaier L, Ellerbrock RH, Rühlmann J, Kalbitz K (2008). Properties of organic matter precipitated from acidic forest soil solutions. Organic Geochemistry 39, 1439–1453.
Properties of organic matter precipitated from acidic forest soil solutionsCrossref | GoogleScholarGoogle Scholar |

Senesi N (1990). Application of electron spin resonance (ESR) spectroscopy in soil chemistry. In ‘Advances in soil science’. (Ed. BA Stewart) pp. 77–130. (Springer: New York, NY)

Stevenson FJ (1994). ‘Humus chemistry: genesis, composition, reactions.’ (John Wiley & Sons: Hoboken NJ)

Strawn DG, Baker LL (2009). Molecular characterization of copper in soils using X-ray absorption spectroscopy. Environmental Pollution 157, 2813–2821.
Molecular characterization of copper in soils using X-ray absorption spectroscopyCrossref | GoogleScholarGoogle Scholar | 19446385PubMed |

Suksrichavalit T, Prachayasittikul S, Piacham T, Isarankura-Na-Ayudhya C, Nantasenamat C, Prachayasittikul V (2008). Copper complexes of nicotinic-aromatic carboxylic acids as superoxide dismutase mimetics. Molecules 13, 3040–3056.
Copper complexes of nicotinic-aromatic carboxylic acids as superoxide dismutase mimeticsCrossref | GoogleScholarGoogle Scholar | 19078847PubMed |

Sutton R, Sposito G, Diallo MS, Schulten HR (2005). Molecular simulation of a model of dissolved organic matter. Environmental Toxicology and Chemistry 24, 1902–1911.
Molecular simulation of a model of dissolved organic matterCrossref | GoogleScholarGoogle Scholar | 16152960PubMed |

Town RM, Powell HKJ (1993). Ion-selective electrode potentiometric studies on the complexation of copper(II) by solid-derived humic and fulvic acids. Analytica Chimica Acta 279, 221–233.
Ion-selective electrode potentiometric studies on the complexation of copper(II) by solid-derived humic and fulvic acidsCrossref | GoogleScholarGoogle Scholar |

Vialykh EA, Hassanvand-Gandaei N, Langford CH, Achari G (2018). Fate of zinc oxide nanoparticles in a biosolid slurry characterized for metal complexation characteristics. Journal of Environmental Quality 47, 1267–1274.
Fate of zinc oxide nanoparticles in a biosolid slurry characterized for metal complexation characteristicsCrossref | GoogleScholarGoogle Scholar | 30272775PubMed |

Vialykh EA, Salahub DR, Achari G, Cook RL, Langford CH (2019). Emergent functional behaviour of humic substances perceived as complex labile aggregates of small organic molecules and oligomers. Environmental Chemistry
Emergent functional behaviour of humic substances perceived as complex labile aggregates of small organic molecules and oligomersCrossref | GoogleScholarGoogle Scholar |

Zhang Y, Li J, Su Q, Wang Q, Wu X (2000). Synthesis, structure and spectroscopic properties of an o-phthalate-bridged copper(II) chain complex. Journal of Molecular Structure 516, 231–236.
Synthesis, structure and spectroscopic properties of an o-phthalate-bridged copper(II) chain complexCrossref | GoogleScholarGoogle Scholar |