Linear adsorption coefficient

Just as the Henry law constant is used to quantify the partitioning between air and water, it is useful to define a parameter to quantify the partitioning between soil and water. The linear adsorption coefficient, Kd, has often been defined for this purpose ... 

K Linear, adsorption coefficient k Gas constant, 1.99 cal/deg/mole L Thickness of bioturbated zone n Integer summation variable ip Porosity... 

Here Cg is the mass adsorbed per unit mass of total solids, C (jimol/L) is the concentration in solution at equilibrium, K (L/g) is the linear adsorption coefficient, Cgg is the mass of adsorbed phosphate (per gram of dry sediment) added during the experiment, and Cgo (fimol/g) is the original quantity of phosphate on the surface of the sediment, which is exchangeable with the phosphate added in the experiment. A graph of Cs vs C should be a straight line with slope of K and intercept of Cgo-... 

The linear regression coefficients were R =0.99 for stations E3 and Bl. The linear adsorption coefficients were 189.3 and 248.9 ml/g at stations E3... 

The linear adsorption isotherm curve can be described by the linear adsorption coefficient K. Peak shape and peak position are independent of the concentration. The influence of kinetic effects can be treated independently from the thermodynamic equilibrium. 

It is known that the term L/u is equal to the holdup time tu-In the case of linear chromatography the term dqi/dct is equal to the linear adsorption coefficient K, so that for low concentrations the retention time can be calculated from ... 

This equation is one of the fundamental equations of analytical chromatography and offers the possibility to determine linear adsorption coefficients from analytical retention times. 

For the change of the linear adsorption coefficients Kj on density Mazzotti et al. [26] suggested ... 

Thereby, K o is the linear adsorption coefficient at a reference density po- With it, the linear adsorption coefficient fCj can be calculated for any density p from the information of a reference state. The exponent hi is an empirical parameter, which can be obtained from experimental data. Typical values for hi are in the range... 

The simplest type of isotherm is the linear-distribution coefficient, A d.12 It is also called the partition coefficient, 7. 58 The equation for calculating adsorption at different concentrations is... 

Major problems are associated with using the linear distribution coefficient for describing adsorption-desorption reactions in groundwater systems. Some of these problems include the... 

In the range of linear adsorption behaviour, whatever the number of site types (see Section 2.3.1 for the merging of parameters of two sites), the surface concentration F is related to via an effective linear coefficient, Ah, while the first-order internalisation processes can also be described by an effective first-order constant, k. Thus, equation (39) can be recast, for instance, in terms of r as ... 

Hence, A asurf is expressed in m I. Furthermore, we assume that ATiasurf is not dependent on the concentration of the compound at the surface that is, we assume that we are far from saturating the surface with compound /. This then corresponds to a linear adsorption isotherm for a homogeneous mineral surface, since the sorbate molecules do not feel each other in the gas phase or at the solid surface. Finally, we should point out that in the literature, contrary to the notation used here, gas/solid partition coefficients are often expressed in a reciprocal way that is, the reported... 

Saturation content of adsorbate is 0.17 Ib/lb solid. Accordingly, the coefficient of the linear adsorption isotherm is... 

The slope of this line is the distribution coefficient (Kd), which is the ratio of the arsenic concentration on the adsorbent (Cads) to the concentration of the associated remaining arsenic in the aqueous solution (Csdn). With each linear adsorption isotherm, Kd has only one value. That is, a linear distribution indicates that the partitioning of arsenic between the adsorbent and the solution is constant over the given range of arsenic concentrations (Eby, 2004), 221. If both concentrations (Cads and Csoin) are in the same units (such as molal), Kd is unitless. However, if the adsorbed concentration is given in molal and the dissolved concentration is molar, then Kd has the units of liter/kilogram. 

TABLE 4.7. Adsorption Coefficients (K) and Distribution Coefficients (Kd) for Adsorption of Triallate (Linear Isotherms) and trans- and c/s-Chlordane (Langmuir Isotherms) on Humic Acids (HAs) Isolated from Pig Slurry (PS) and Surface (1) and Whole (2) Horizons of Two Soils (UK and PO)... 

Park, J.H., Lee, H.J. (1993) Estimation of bioconcentration factor in fish, adsorption coefficient for soils and sediments and interfacial tension with water for organic nonelectorlytes based on the linear solvation energy relationships. Chemosphere 26, 1905-1916. 

The system of differential equations is too complex to be solved analytically. Assumptions of a linear adsorption isotherm can be used to obtain analytical solutions, but this approach is generally not applicable to describe affinity chromatography experiments. Several numerical techniques arc used to solve the system of partial differential equations. The other method is to use an analytical solution with simplifying approaches [32] that describe the adsorption process with a single step and a lumped mass transfer coefficient [27],... 

Different charge-compensating cations in zeolite L have been tested for their promotional effect in n-hexane aromatization. Apparently, high basicity of the alkaline and alkaline earth promoter favors n-hexane aromatization. Basicity and selectivity both increase from Li and Cs 331) and from Mg to Ba (22,25). Bezouhanova et al. studied the FTIR bands of linearly adsorbed CO in the range of 2060-2075 cm . One band at 2075 cm", which is also found on unsupported Pt, is attributed to extrazeolite Pt particles, a second band shifts from 2060 cm" for Li to lower wavenumbers with K and Rb 331). Another criterion, used by Larsen and Haller, is the measured rate of competitive hydrogenation of benzene and toluene, which has been found to correlate with the zeolite basicity (25). As described in a previous section, this method had previously been used by Tri el al. to probe for the electron deficiency of Pt particles in acidic zeolites 332). The rate data are analyzed in terms of a Langmuir-Hinshelwood model and the ratio of the adsorption coefficients of toluene and benzene, A, /b, is determined. It was found to decrease from 8.6 for Pt/Si02, and 5.4 for Pt/MgL, to 4.4 for Pt/BaL. As direct electron transfer from the cations to neutral Pt particles is unlikely, an interaction of Pt with the zeolite framework or with... 

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