Influence of aggregation on the uptake kinetics of phosphate by goethite

Anderson, Marc A.; Tejedor-Tejedor, M. Isabel; Stanforth, Robert

doi:10.1021/es00137a009

Cited by 86 publications

(66 citation statements)

References 4 publications

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“…At PT > 10 ~mol kg 1, it is difficult to quantify precisely the small difference between 2 relatively large quantities (numerator of Equation [1]) and so reliable adsorption data are limited to lower values of PT" Adsorption kinetic data are presented in Figure 1 for PT = 0.32, 0.83 and 3.12 ixmol kg 1. The quantities of P adsorbed are comparable to values reported by others for iron oxides suspended in similar aqueous media (Sigg and Stumm 1981;Anderson et al 1985). Most of the phosphate adsorbed within the time frame of the experiment (24 h) is removed from solution within the first few minutes of reaction.…”

Section: Phosphate Adsorptionsupporting

confidence: 88%

“…As a result of chemical interactions, the magnitude of phosphate adsorbed to iron oxides is sensitive to the surface site/dissolved phosphate concentration ratio (Anderson et al 1985). Therefore, to maintain consistent particle surface chemistry, the same particle concentration was used in adsorption, electrophoresis and coagulation experiments (10 mg kg-1).…”

Section: Phosphate Adsorptionmentioning

confidence: 99%

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

Chorover

Zhang

Amistadi

et al. 1997

Clays and clay miner.

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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 (KC1) concentration or surface complexing anion (H2PO4) concentration, PT, at pH 6.0 ~ 0.1. Diffusion limited aggregation (DLA) was induced by counterion screening at [KC1] > 80 mM or by surface charge neutralization at Pr = 31 IxM (and ionic strength = 1.0 raM). In DLA, the fractal dimension, de, of aggregates formed by either surface charge neutralization or counterion screening was 1.7 2 0.1. A reduction in the rate of coagulation in KC1 for [KC1] < 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.

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Section: Phosphate Adsorptionsupporting

confidence: 88%

Section: Phosphate Adsorptionmentioning

confidence: 99%

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

Chorover

Zhang

Amistadi

et al. 1997

Clays and clay miner.

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“…Because this ratio explained most of the variance in P sed (Table 4), authigenic iron precipitation appeared as the main factor controlling the concentration of P sed in the Lozoya reservoirs. There is wide evidence of the association of phosphorus and iron oxides in sediments (Lijklema 1980, Froelich 1988, Baldwin 1996, Saavedra and Delgado 2005 and several studies have focused on the mechanisms of the phosphorus fixation onto Fe particles (Anderson et al 1985) and physico-chemical structure of the iron particles containing phosphorus (Lienemann et al 1999). Classically, it was assumed that phosphorus and iron were related through abiotic processes, but it has become increasingly evident that bacterial processes may be directly or indirectly involved in this relationship (Gachter and Meyer 1993;Mitchell and Baldwin 1998).…”

Section: Discussionmentioning

confidence: 99%

Sedimentary phosphorus in a cascade of five reservoirs (Lozoya River, Central Spain)

López

Marcé

Ordóñez

et al. 2009

Lake and Reservoir Management

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“…However, other mechanisms, such as precipitation, cannot be excluded (Jonasson et al, 1988;Martin et aL, 1988). Synthetic goethites frequently have a phosphate sorption capacity of about 2.5/zmol P/m 2 at moderately acid to neutral pH values (Hingston, 1981;Cabrera et al, 1981;Borggaard, 1983a;Anderson et al, 1985;Torrent et al, 1990). This value is compatible with the formation of a binuclear surface complex on the (110) faces, which are the ones observed under the transmission electron microscope (TEM) (Schwertmann, 1984;Mann et al, 1985), rather than the generally assumed (100) faces.…”

Section: Introductionmentioning

confidence: 99%

Fast and Slow Phosphate Sorption by Goethite-Rich Natural Materials

Torrent

Schwertmann

Barrón

1992

Clays and clay miner.

170

100

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Abstract--Although phosphate sorption by goethite and other less-abundant Fe oxides strongly influences the concentration of this anion in the soil solution and aquatic environments, relatively little is known on the P-sorption characteristics of natural goethites. For this reason, we examined the P-sorption capacity and time course ofP sorption of 10 goethite-rich soil, ferricrete and lake ore samples, in which the content and nature of mineral impurities were unlikely to affect P sorption significantly. Phosphate sorption could be adequately described by a modified Freundlich equation including a time term. The amount of P sorbed after i day of equilibration at a concentration of 1 mg P/liter ranged widely (0.36-2.04 #mol P/m2). The total P sorbed after 75 days of equilibration varied less, in relative terms (1.62-3.18 #tool p/m2), i.e., a higher slow sorption tended to compensate for a lower initial (fast) sorption. Total sorbed P (X = 2.62, SD = 0.52 ~mol P/m 2) was similar to the sorption capacity of synthetic goethites, suggesting a common sorption mechanism and the predominance of one type of crystal face, which, according to previous transmission electron microscope observations, might be the (110).The extent of the slow reaction correlated to the ratio between micropore surface area and total surface area, as well as to oxalate-extractable Fe, which is an estimation of the ferrihydrite content. Ferrihydrite impurities might affect the slow reaction by contributing to the microporosity of some samples. Silicate adsorbed on the surface of the goethites was readily desorbed during phosphate sorption and did not significantly affect the extent of the slow sorption process.

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Influence of aggregation on the uptake kinetics of phosphate by goethite

Cited by 86 publications

References 4 publications

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

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

Sedimentary phosphorus in a cascade of five reservoirs (Lozoya River, Central Spain)

Fast and Slow Phosphate Sorption by Goethite-Rich Natural Materials

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