Modeling the effects of Ca2+ and clay-associated organic carbon on the stability of colloids from topsoils

Séquaris, J.‐M.

doi:10.1016/j.jcis.2009.12.014

Cited by 25 publications

(17 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Humic acids adsorbed on natural surfaces increased the electrostatic interaction

Δ G_{131}^{EL}

by about 100 kT, mainly from the increase in negative charge (zeta potential from −21 to −24 mV, Table ). Séquaris () reported a similar effect of more stability in soil colloid dispersion in the presence of organic carbon, which is attributed to an increase in zeta potential leading to electrostatic repulsion. Despite this, a moderate but noteworthy difference of about 50 kT in surface potentials between the natural plus HA and the two H 2 O 2 ‐treated samples was observed.…”

Section: Resultsmentioning

confidence: 86%

“…This indicates no HA adsorption on H 2 O 2 -treated surfaces, which were also less favourable for soil particle flocculation and aggregation. According to Séquaris (2010), these results could be extended to other cations such as calcium. On the contrary, in sodium solutions mineral surfaces with their own organic matter provide the most favourable flocculation conditions; they had the smallest surface potentials (< 300 kT at 10 nm).…”

Section: Total Energy Of Interaction Between Soil Particlesmentioning

confidence: 86%

See 1 more Smart Citation

Humic acid adsorption and its role in colloidal‐scale aggregation determined with the zeta potential, surface free energy and the extended‐DLVOtheory

Calero

Ontiveros-Ortega

Aranda

et al. 2017

European J Soil Science

View full text Add to dashboard Cite

Summary The effect of colloidal forces involved in the adsorption of commercial humic acids (HAs) and particle cohesion was studied in the soil of an organic olive grove with the extended Derjaguin, Landau, Verwey and Overbeek (extended‐DLVO) theory. Total interaction energy was determined from the zeta potential (ζ) and surface free energy, measured under different experimental conditions [natural and hydrogen peroxide (H2O2) organic matter‐free mineral surfaces]. The soil was clayey, dominated by illite and vermiculite. It showed electron‐donor behaviour, with negatively charged surfaces and zeta potential < 0 mV. Decreasing mV in the zeta potential, ζ, curves and electron‐donor component, γ–, when adding HA to natural surfaces showed effective HA adsorption, but only when soil organic matter had not been removed previously. Isotherms confirmed adsorption by natural soil (> 2.5 mg C g−1). Because the isotherms showed no relation with temperature, adsorption would be better attributed to weak physical interactions. On natural surfaces with HA, soil particle attraction forces increased slightly (≈50 kT) through decreasing soil wettability. However, this effect on total surface energy was overcome largely by increasing electrostatic repulsive energy caused by the adsorption of negatively charged HA (> 300 kT). The DLVO‐extended model showed that natural surfaces without H2O2 treatment or added HA seem to be the most favourable state for colloidal aggregate stability. We recommend some caution about the type and quality of organic matter added to increase organic carbon in soil. Highlights We applied the extended DLVO model to study humic acid adsorption and its effects on soil structure. Adsorption on soil surfaces with their natural organic matter was mostly by weak physical forces. Adsorption increased the total particle interaction energy through an increase in electrostatic repulsion. Adsorption of some types of organic matter might decrease the colloidal stability of aggregates.

show abstract

“…Humic acids adsorbed on natural surfaces increased the electrostatic interaction

Δ G_{131}^{EL}

Section: Resultsmentioning

confidence: 86%

Section: Total Energy Of Interaction Between Soil Particlesmentioning

confidence: 86%

Humic acid adsorption and its role in colloidal‐scale aggregation determined with the zeta potential, surface free energy and the extended‐DLVOtheory

Calero

Ontiveros-Ortega

Aranda

et al. 2017

European J Soil Science

View full text Add to dashboard Cite

show abstract

“…The critical coagulation concentrations (CCC) of Ca 2+ and Na + (Séquaris, ; Jiang et al , ) for WDC aggregation were investigated after diluting 5 g l −1 of freeze‐dried WDC, which was vigorously shaken for 12 hours after ultrasonication for 4 minutes. The dispersion was sonicated for another 10 minutes before measurements were taken.…”

Section: Methodsmentioning

confidence: 99%

“…The Malvern Nano-ZS apparatus was also used to calculate the zeta potential (ζ ) from the micro-electrophoretic mobility of WDC samples. PCS and electrokinetic investigations were performed after dilution (1:10) of the fractionated WDC colloidal phase with the electrolyte phase solution at 20 • C. The critical coagulation concentrations (CCC) of Ca 2+ and Na + (Séquaris, 2010;Jiang et al, 2012) for WDC aggregation were investigated after diluting 5 g l −1 of freeze-dried WDC, which was vigorously shaken for 12 hours after ultrasonication for 4 minutes. The dispersion was sonicated for another 10 minutes before measurements were taken.…”

Section: Characterization Of Water-dispersible Colloids (Wdcs)mentioning

confidence: 99%

Diffusion‐controlled mobilization of water‐dispersible colloids from three German silt loam topsoils: effect of temperature

Jiang

Séquaris

Vereecken

et al. 2013

European J Soil Science

View full text Add to dashboard Cite

Summary The effects of time and temperature on the release kinetics of water‐dispersible colloids (WDCs) from three German silt loam topsoils in deionized water were investigated in batch experiments under low‐energy rotating shaking conditions. The measured critical coagulation concentrations of Ca2+ and Na+ for extracted WDC were much larger than the experimental ionic conditions. This indicates a fast dispersion rate in the first detachment step of WDC mobilization from soil aggregates. The cumulative released WDC fraction F(t) (released WDC/clay content in bulk soil) was satisfactorily fitted to the square root of shaking time by a linear function in three soils with a similar clay content. This implies diffusion‐controlled release kinetics in the second step of the WDC mobilization process. The mobilization kinetics were modelled by considering a diffusion‐controlled transport through an immobile water layer in the macropores of soil aggregates formed by silt and sand particles. The effects of temperature on the mobilization kinetics and sedimentation volumes of saturated soils were compared at 7, 23 and 35°C. A linear correlation was found between immobile water layer thickness in soil macropores (lt) and the water volume (Vwater) in soil sediment, which indicates a strong dependence of lt on the soil texture. Temperature‐sensitive lt and Vwater influenced the effect of temperature on WDC release, which counteracts the estimated effect of temperature on particle diffusion according to the Stokes‐Einstein relation. A larger decrease in F(t) was found in grassland and forest soils than in an arable soil and can be related to greater stagnant water contents (larger lt and Vwater) in soil macropores, where particulate organic matter and polyvalent cations in their oxide forms at acidic pH will thus contribute to water immobilization.

show abstract

“…Goldberg et al, 1990;Igwe et al, 2009), and the type and amount of exchangeable cations (e.g. Levy and Torrento, 1995;Sequaris, 2010). These findings have significantly improved our understanding of the factors controlling colloid dispersion and the associated mobilization and transport of nutrients and contaminants in the natural environment.…”

Section: Introductionmentioning

confidence: 91%

Pedogenesis significantly decreases the stability of water-dispersible soil colloids in a humid tropical region

et al. 2016

View full text Add to dashboard Cite

The stability of soil colloids influences soil physicochemical properties, soil development, and transfer of nutrients and contaminants to surface and ground waters. A better understanding of soil colloids stability dynamics during soil evolution is important for the evaluation of soil's capacity to retain nutrients and/or accommodate toxic contaminants. This study was aimed to determine changes in the stability of water-dispersible soil colloids that accompany mineral transformation and surface charge evolution during pedogenesis using a well characterized chronosequence derived from basalt in the humid tropical region of Hainan Island, South China. The results demonstrated that the pH-dependent colloid stability decreased significantly with tropical soil development, which we attribute to the substantial changes in clay mineral compositions and colloid surface charge properties. Clay minerals in the studied chronosequence were characterized by an increase of kaolinite, gibbsite and Fe oxides and a decrease of quartz and halloysite towards more advanced stages of weathering, which resulted in the decline of permanent negative charges in the older soils. The point of zero charge (pH PZC ) increased while ΔpH decreased across the tropical soil chronosequence, being in good agreement with the observed lower colloid stability in aged soils dominated by kaolinitic minerals. Our study of colloid stability at long-term pedogenic time scale suggests young tropical soils (b 180 ka) with high surface charge are subjected to higher risk of clay movement and colloid-facilitated nutrients and contaminants transport. Careful management practices are thus required to avoid colloids dispersion and transport in young tropical soils either by reducing the frequency/intensity of pore-water flow or by liming to counter the high permanent negative charges.

show abstract

Modeling the effects of Ca2+ and clay-associated organic carbon on the stability of colloids from topsoils

Cited by 25 publications

References 49 publications

Humic acid adsorption and its role in colloidal‐scale aggregation determined with the zeta potential, surface free energy and the extended‐DLVOtheory

Humic acid adsorption and its role in colloidal‐scale aggregation determined with the zeta potential, surface free energy and the extended‐DLVOtheory

Diffusion‐controlled mobilization of water‐dispersible colloids from three German silt loam topsoils: effect of temperature

Pedogenesis significantly decreases the stability of water-dispersible soil colloids in a humid tropical region

Contact Info

Product

Resources

About