Author
R. J. Atkinson
Other affiliations: University of Papua New Guinea
Bio: R. J. Atkinson is an academic researcher from University of Western Australia. The author has contributed to research in topics: Phosphate & Adsorption. The author has an hindex of 9, co-authored 10 publications receiving 1927 citations. Previous affiliations of R. J. Atkinson include University of Papua New Guinea.
Papers
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597 citations
TL;DR: The specific adsorption of anions depends on the pK values of the anion acids and the adsorbed anions confer a negative charge on the surface displacing the zero point of charge to lower pH values.
Abstract: The specific adsorption of anions depends on the pK values of the anion acids The adsorbed anions confer a negative charge on the surface displacing the zero point of charge to lower pH values
435 citations
333 citations
TL;DR: In this article, a series of 0·5 molal Fe(III) hydroxide gels were produced by aging the gels at 60°C in the presence of excess NaOH and examined qualitatively by electron microscopy, selected area diffraction and X-ray diffractometry.
238 citations
TL;DR: In this paper, it was shown that the bridging binuclear complex of the type Fe-O-P-O(O-Fe) can be found in the presence of water.
Abstract: SYNTHETIC goethite has been extensively studied as a model adsorbent in the search for a precise description of the chemical reactions involved in phosphate adsorption by soil minerals. Infrared studies1,2 have now firmly established that phosphate on goethite and other iron oxides results in a bridging binuclear complex of the type Fe–O–P–O–Fe. The infrared studies were, however, carried out on dried samples of phosphated goethite. We now report infrared studies on wet goethite films which confirm that the binuclear complex exists in the presence of water.
107 citations
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TL;DR: An overview of second-order kinetic expressions is described in this paper based on the solid adsorption capacity, which shows that a pseudo-second-order rate expression has been widely applied to the Adsorption of pollutants from aqueous solutions onto adsorbents.
3,458 citations
TL;DR: In this article, a method for determination of intrinsic ionization and complexation constants of oxide surface sites from potentiometric titration data is reported using these experimental properties and the stoichiometry of surface reactions, surface charge, σo, adsorption density, Γi, and diffuse layer potentials, ψd, at the oxide/water interface.
1,493 citations
TL;DR: In this paper, the long-term stabilization of soil organic matter (SOM) in tropical and temperate regions is mediated by soil biota (e.g. fungi, bacte- ria, roots and earthworms), soil structure and their interactions.
Abstract: The long-term stabilization of soil organic matter (SOM) in tropical and temperate regions is mediated by soil biota (e.g. fungi, bacte- ria, roots and earthworms), soil structure (e.g. aggregation) and their interactions. On average, soil C turnover was twice as fast in tropical com- pared with temperate regions, but no major differences were observed in SOM quality between the two regions. Probably due to the soil mineralogy dominated by 1:1 clay minerals and oxides in tropical regions, we found a higher aggregate stability, but a lower correlation between C contents and aggregate stability in tropical soils. In addition, a smaller amount of C associated with clay and silt particles was observed in tro- pical versus temperate soils. In both tropical and temperate soils, a general increase in C levels (≈ 325 ± 113 kg C·ha -1 ·yr -1 ) was observed under no-tillage compared with conventional tillage. On average, in temperate soils under no-tillage, compared with conventional tillage, CH4 uptake (≈ 0.42 ± 0.10 kg C-CH4·ha -1 ·yr -1
1,200 citations
TL;DR: In this article, the As and Fe K-edges were collected from samples of two-line ferrihydrite with adsorbed (ADS) and coprecipitated (CPT) arsenate prepared over a range of conditions and arsenate surface coverages.
1,123 citations
TL;DR: A sequential extraction method (SEDEX) was developed to separate five sedimentary P reservoirs: loosely sorbed P; ferric iron-bound P; authigenic carbonate fluorapatite + biogenic apatite+ CaCO3-associated P; detrital apatitic P; and organic P.
Abstract: A sequential extraction method (SEDEX) has been developed to separately quantify five sedimentary P reservoirs: loosely sorbed P; ferric iron-bound P; authigenic carbonate fluorapatite + biogenic apatite + CaCO3-associated P; detrital apatite P; and organic P. The SEDEX method successfully separates two of the main categories of authigenic phosphate phases called upon most often as sedimentary sinks for diagenetically mobilized P: ferric oxyhydroxide-associated P and authigenic carbonate fluorapatite (CFAP). It offers a means for separating authigenic CFAP from detrital apatite of igneous or metamorphic origin. The importance of this distinction is that CFAP represents an oceanic sink for reactive P, whereas detrital apatite does not. In addition, a means for reversing secondary adsorption of P onto residual solid surfaces during extraction has been developed.
Extensive standardization of the SEDEX method for application to marine sediments has been performed with analogs for naturally occurring phosphatic phases.
1,016 citations