http://libir.tmu.edu.tw/bitstream/987654321/43034/1/4.pdf

Review of second-order models for adsorption systems.

Surface ionization and complexation at the oxide/water interface

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

/pdf/soil-organic-matter-biota-and-aggregation-in-temperate-and-4fy8bn1320.pdf

Soil organic matter, biota and aggregation in temperate and tropical soils - Effects of no-tillage

Surface chemistry of ferrihydrite: Part 1. EXAFS studies of the geometry of coprecipitated and adsorbed arsenate

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.

https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1992.37.7.1460

Development of a sequential extraction method for different forms of phosphorus in marine sediments

Adsorption of potential-determining ions at the ferric oxide-aqueous electrolyte interface

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

Specific Adsorption of Anions

The Mechanism of Phosphate Fixation by Iron Oxides

Crystal nucleation in Fe(III) solutions and hydroxide gels

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.

R. J. Atkinson

Papers

Adsorption of potential-determining ions at the ferric oxide-aqueous electrolyte interface

Specific Adsorption of Anions

The Mechanism of Phosphate Fixation by Iron Oxides

Crystal nucleation in Fe(III) solutions and hydroxide gels

Phosphate adsorption on goethite (α-FeOOOH)