Comparison of Five Adsorption Isotherms for Prediction of Zinc Retention in Calcareous Soils and the Relationship of their Coefficients with Soil Characteristics

Reyhanitabar, Adel; Karimian, N.; Ardalan, M.; Savaghebi, G.; Ghannadha, M. R.

doi:10.1080/00103620601094049

Cited by 19 publications

(7 citation statements)

References 17 publications

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“…R L value indicates the adsorption nature to be either unfavorable (R L > 1), linear (R L = 1), favorable (0 <R L < 1) or irreversible (R L = 0). The maximum buffering capacity (MBC) was calculated as the product of K L and b following Reyhanitabar et al (34).…”

Section: Materials and Methods Sample Collection And Physicochemical mentioning

confidence: 99%

Potassium Adsorption in Calcareous Soils of Kurdistan Region of Iraq

Mam-Rasul¹

2020

Iraqi J. Agric. Sci.

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Sorption is one of the most chemical important processes, which determine nutrients availability in soil. Sorption isotherms provide sufficient information about soils sorption’s capacity, and it’s data can be used to determine thermodynamic sorption parameters. The aim of this studyis to evaluate the sorption of potassium onto some soils. An experiment was conducted with four calcareous soils of the Sulaimani province Kurdistan Region of Iraq by using the batch methods. 5g soil samples were equilibrated at 298±1 Kelvin with 50 ml of 0.01M CaCl2 containing 0 to 250 mg L-1 K as KCl. Suspensions were centrifuged, filtered, and concentration of K+ in the clear extract solution was determined. Amount of K+ sorbed by the soil was calculated from the difference between the initial and final concentration of K+ in the equilibrium solution. Sorption of K+ was evaluated using adsorption isotherms. The results showed that K+ sorption was described by linear, Langmuir, Freundlich, and Temkin equations. Langmuir equation gave a better fit of equilibrium K adsorption when it has a higher R2 and lowers SE. The data indicated that the maximum monolayer coverage capacity (b) from the Langmuir isotherm model ranged between (-113.63 to 2500) mg kg-1. The negative values of (b) for studied locations soils indicated to potassium release instead of adsorption. The Langmuir isotherm constant (KL) ranged from (-0.01 to 0.01) L mg-1. Maximum buffering capacity (MBC) is a capacity factor, which measures the ability of the soil to replenish K ion to soil solution that the ability of a soil to supply K to the soil solution. The value of MBC of the studied soils ranged from 0.453 to 23.75 mg kg-1.The sorption processes for the forth locations are favorable and spontaneous because the value of RL was an equal one.

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Section: Materials and Methods Sample Collection And Physicochemical mentioning

confidence: 99%

Potassium Adsorption in Calcareous Soils of Kurdistan Region of Iraq

Mam-Rasul¹

2020

Iraqi J. Agric. Sci.

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“…The final equation for surface coverage (hereinafter referred to as the Gauss adsorption function) in the approximation used reads taking into account Eqs. (15)- (17) and (20)…”

Section: Surface Coverage At Medium Pressurementioning

confidence: 99%

“…This is a quasi‐passive surface whose adsorption centres are virtual. At last, the constant distribution function in the Temkin case for evenly heterogeneous surfaces that is highly actual for modeling of adsorption, e. g., on metals (in particular, iron and steels, zinc, gold, incl. nanoparticles), activated carbon and alumina etc.

true f_{T} ((), ϵ) = \frac{1}{2 σ} normalH (() ϵ - ϵ_{0} + σ) \cdot ([] 1 - H (ϵ - ϵ_{0} - σ)),

…”

Section: Introductionmentioning

confidence: 99%

An Asymptotically Exact Analytical Solution for the Isotherm Based on the Gaussian Distribution on Adsorption Heat

2019

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Given a surface energetic heterogeneity as the normal distribution function, the approximate analytical solution has been obtained that resembles the true isotherm at both low‐ and high‐pressure limits as well as reproduces its intermediate, so‐called centrosymmetric, point. An asymptotic complement property that introduces a continuous mapping of the isotherm onto itself has been formulated, proved and shown to be applicable to a whole class of surfaces. The limiting or degenerative cases on energetically homogeneous (the Langmuir case), evenly heterogeneous (the Temkin case) and quasi‐passive surface have been considered. The role of the heterogeneity parameters of the overall Gauss isotherm has been studied. An algorithm to determine the adsorption heat characteristics of the surface has been built. Hints for future use of the asymptotic complement property have been given.

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“…These Aridisols and Entisols generally contain quite large quantities of total Zn, but have only very small quantities of Zn in soil solution. Most of these soils need supplemental Zn for optimum plant growth (Malakouti, 1992;Reyhanitabar et al, 2007) and the recovery of applied Zn by plants is low. Even where Zn chelate (Zn-EDTA) was applied only 5% or less was recovered by the first crop (Maftoun and Karimian, 1989;Darjeh et al, 1991).…”

Section: Introductionmentioning

confidence: 99%