Hostname: page-component-77c89778f8-sh8wx Total loading time: 0 Render date: 2024-07-18T17:09:49.278Z Has data issue: false hasContentIssue false

Comparison of Hematite Coagulation by Charge Screening and Phosphate Adsorption: Differences in Aggregate Structure

Published online by Cambridge University Press:  28 February 2024

Jon Chorover
Affiliation:
Department of Inorganic, Analytical and Applied Chemistry, University of Geneva, Sciences II, 1211 Geneva 4, Switzerland Department of Agronomy, The Pennsylvania State University, University Park, Pennsylvania 16802-3504
Jingwu Zhang
Affiliation:
Department of Inorganic, Analytical and Applied Chemistry, University of Geneva, Sciences II, 1211 Geneva 4, Switzerland
Mary Kay Amistadi
Affiliation:
Department of Agronomy, The Pennsylvania State University, University Park, Pennsylvania 16802-3504
Jacques Buffle
Affiliation:
Department of Inorganic, Analytical and Applied Chemistry, University of Geneva, Sciences II, 1211 Geneva 4, Switzerland

Abstract

The formation and structure of hematite aggregates were examined by dynamic and static light scattering techniques. A large range in coagulation kinetics was studied by varying either indifferent electrolyte (KCl) concentration or surface complexing anion (H2PO4-) concentration, PT, at pH 6.0 ± 0.1. Diffusion limited aggregation (DLA) was induced by counterion screening at [KCl] > 80 mM or by surface charge neutralization at P T = 31 μM (and ionic strength =1.0 mM). In DLA, the fractal dimension, df, of aggregates formed by either surface charge neutralization or counterion screening was 1.7 ± 0.1. A reduction in the rate of coagulation in KCl for [KCl] > critical coagulation concentration (CCC) produced an increase in df to 2.1 ± 0.1. For aggregation induced by phosphate adsorption at constant ionic strength, there was no apparent trend in df with coagulation rate. The value of df was consistently less than 1.8 when reaction limited aggregation (RLA) resulted from surface charge neutralization rather than counterion screening. TEM observations of aggregates formed in the presence or absence of phosphate confirm that, when RLA is induced by phosphate adsorption, resulting aggregates are much looser in structure than those formed by counterion screening. The results suggest that the high-affinity binding of phosphate to hematite may result in a nonrandom distribution of surface charge that facilitates the coalescence of positive and negative charge crystal faces.

Type
Research Article
Copyright
Copyright © 1997, The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Amal, R. Raper, J.A. and Waite, T.D., 1990 Fractal structure of hematite aggregates J Colloid Interface Sci 140 158168 10.1016/0021-9797(90)90331-H.CrossRefGoogle Scholar
Anderson, M.A. Tejedor-Tejedor, M.I. and Stanforth, R.R., 1985 Influence of aggregation on the uptake kinetics of phosphate by goethite Environ Sci Technol 19 632637 10.1021/es00137a009.CrossRefGoogle ScholarPubMed
Asnaghi, D. Carpineti, M. Giglio, M. and Sozzi, M., 1992 Coagulation kinetics and aggregate morphology in the intermediate regimes between diffusion-limited and reaction-limited cluster aggregation Phys Rev A 45 10181023 10.1103/PhysRevA.45.1018.CrossRefGoogle ScholarPubMed
Barrón, V. and Torrent, J., 1996 Surface hydroxyl configuration of various crystal faces of hematite and goethite J Colloid Interface Sci 177 407410 10.1006/jcis.1996.0051.CrossRefGoogle Scholar
Carpineti, M. Ferri, F. Giglio, M. Paganini, E. and Perini, U., 1990 Salt-induced fast aggregation of polystyrene latex Phys Rev A 42 73477354 10.1103/PhysRevA.42.7347.CrossRefGoogle ScholarPubMed
Colic, M. Fuerstenau, D.W. Kallay, N. and Matijevic, E., 1991 Inotropic effect in surface charge, electrokinetics, and coagulation of a hematite dispersion Colloid Surf 59 169185 10.1016/0166-6622(91)80246-K.CrossRefGoogle Scholar
Columbo, C. Barrón, V. and Torrent, J., 1994 Phosphate adsorption and desorption in relation to morphology and crystal properties of synthetic hematites Geochim Cosmochim Acta 58 12611269 10.1016/0016-7037(94)90380-8.CrossRefGoogle Scholar
Evans, D.F. and Wennerström, H., 1994 The colloidal domain New York VCH.Google Scholar
Frosh, D. and Westphal, C., 1989 Melamime resins and their application in electron microscopy Electron Microsc Rev 2 231255 10.1016/0892-0354(89)90002-6.CrossRefGoogle Scholar
Hackley, V.A. and Anderson, M.A., 1989 Effects of short-range forces on the long range structure of hydrous iron-oxide aggregates Langmuir 5 191198 10.1021/la00085a036.CrossRefGoogle Scholar
Hunter, R.J., 1987 Foundations of colloid science, vol. 1 New York Oxford Univ Pr.Google Scholar
Jullien, R. and Botet, R., 1987 Aggregation and fractal aggregates Singapore World Scientific.Google Scholar
Kerker, M. Sheiner, P. Cooke, D.D. and Kratohvil, J.P., 1979 Adsorption index and color of colloidal hematite J Colloid Interface Sci 71 176187 10.1016/0021-9797(79)90231-5.CrossRefGoogle Scholar
Liang, L. and Morgan, J.J., 1990 Chemical aspects of iron oxide coagulation in water: Laboratory studies and implications for natural systems Aquatic Sci 52 3255 10.1007/BF00878240.CrossRefGoogle Scholar
Lin, M.Y. Lindsay, H.M. Weitz, D.A. Ball, R.C. Klein, R. and Meakin, P., 1989 Universality of fractal aggregates as probed by light scattering Proc R Soc Lond A 423 7187 10.1098/rspa.1989.0042.Google Scholar
Meakin, P., 1991 Fractal aggregates in geophysics Rev Geophys 29 317331 10.1029/91RG00688.CrossRefGoogle Scholar
Murphy, J. and Riley, J.P., 1962 A modified single solution method for the determination of phosphate in natural waters Anal Chim Acta 27 3136 10.1016/S0003-2670(00)88444-5.CrossRefGoogle Scholar
O’Melia, C.R., 1989 Particle-particle interactions in aquatic systems Colloid Surf 39 255271 10.1016/0166-6622(89)80191-X.CrossRefGoogle Scholar
Parfitt, R.L. and Atkinson, R.J., 1976 Phosphate adsorption on goethite (α-FeOOH) Nature 264 740742 10.1038/264740a0.CrossRefGoogle Scholar
Parfitt, R.L. Russell, J.D. and Farmer, V.C., 1976 Confirmation of the surface structures of goethite (α-FeOOH) and phosphated goethite by infrared spectroscopy J Chem Soc Faraday Trans 1 72 10821087 10.1039/f19767201082.CrossRefGoogle Scholar
Pecora, R., 1985 Dynamic light scattering New York Plenum Publishing 10.1007/978-1-4613-2389-1.CrossRefGoogle Scholar
Penners, N.H.G. and Koopal, L.K., 1986 Preparation and optical properties of homodisperse haematite hydrosols Colloid Surf 19 337349 10.1016/0166-6622(86)80287-6.CrossRefGoogle Scholar
Penners, N.H.G. Koopal, L.K. and Lyklema, J., 1986 Interfacial electrochemistry of haematite (α-Fe2O3): Homodisperse and heterodisperse sols Colloid Surf 21 457468 10.1016/0166-6622(86)80109-3.CrossRefGoogle Scholar
Perret, D. Leppard, G.G. Müller, M.M. Belzile, N. De Vitre, R. and Buffle, J., 1992 Electron microscopy of aquatic colloids: Non-perturbing preparation of specimens in the field Wat Res 25 3331343.Google Scholar
Pfeifer, P. Obert, M. and Avnir, D., 1989 Fractals: Basic concepts and terminology The fractal approach to heterogeneous chemistry New York J. Wiley 1143.Google Scholar
Russell, J.D. Parfitt, R.L. Fraser, A.R. and Farmer, V.C., 1974 Surface structures of gibbsite, goethite, and phosphated goethite Nature 248 220221 10.1038/248220a0.CrossRefGoogle Scholar
Schmidt, P.W. and Avnir, D., 1989 Use of scattering to determine the fractal dimension The fractal approach to heterogeneous chemistry New York J. Wiley 6779.Google Scholar
Schurtenberger, P. and Newman, M., 1993 Characterization of biological and environmental particles using static and dynamic light scattering Environmental particles 2 37115.Google Scholar
Sigg, L. and Stumm, W., 1981 The interaction of anions and weak acids with the hydrous goethite surface Colloid Surf 2 101117 10.1016/0166-6622(81)80001-7.CrossRefGoogle Scholar
Sposito, G., 1992 Characterization of particle surface charge Environmental particles 1 291314.Google Scholar
Sposito, G., 1994 Chemical equilibria and kinetics in soils New York Oxford Univ Pr.CrossRefGoogle Scholar
Stumm, W. Furrer, G. and Stumm, W., 1987 The dissolution of oxides and aluminum silicates: Examples of surface-coordination controlled kinetics Aquatic surface chemistry New York J. Wiley 197219.Google Scholar
Stumm, W. and Morgan, J.J., 1996 Aquatic chemistry 3rd New York J. Wiley.Google Scholar
Teixeira, J., Stanley, H.E. and Ostrowski, N., 1986 Experimental methods for studying fractal aggregates On growth and form: Fractal and non-fractal patterns in physics Dordrecht Martinus-Nijhoff 145162 10.1007/978-94-009-5165-5_9.CrossRefGoogle Scholar
Teixeira, J., 1988 Small-angle scattering by fractal systems J Appl Cryst 21 781785 10.1107/S0021889888000263.CrossRefGoogle Scholar
Tejedor-Tejedor, M.I. and Anderson, M., 1990 Protonation of phosphate on the surface of goethite as studied by CIR-FTIR and electrophoretic mobility Langmuir 6 602611 10.1021/la00093a015.CrossRefGoogle Scholar
Verwey, E.J.W. and Overbeek, J.T.G., 1948 Theory of the stability of lyophobic colloids Amsterdam Elsevier.Google Scholar
Weitz, D.A. Huang, J.S. Lin, M.Y. and Sung, J., 1985 Limits of the fractal dimension for irreversible kinetic aggregation of gold colloids Phys Rev Lett 54 14161421 10.1103/PhysRevLett.54.1416.CrossRefGoogle ScholarPubMed
Zhang, J. and Buffle, J., 1995 Kinetics of hematite aggregation by polyacrylic acid J Colloid Interface Sci 174 500509 10.1006/jcis.1995.1417.CrossRefGoogle Scholar
Zhang, J. and Buffle, J., 1996 Multi-method determination of the fractal dimension of hematite aggregates Colloid Surf A 107 175188 10.1016/0927-7757(95)03344-0.CrossRefGoogle Scholar