Langmuir {soilchemistry}

Langmuir isotherm fitted to adsorption data

Description

The linear form of Langmuir adsorption isotherm can be fitted to adsorption data to find out adsorption maxima, affinity coefficient, and maximum buffering capacity (Langmuir, 1918).

Usage

Langmuir(W = W, V = V, Ci = Ci, Cf = Cf,...)

Arguments

W

Mass of soil sample (g)

V

Volume of extractant solution (mL)

Ci

Initial concentration (mg/L) of the added element, e.g., phosphorus

Cf

Final or equilibrium concentration (mg/L) after adsorption of the same element

...

Any other argument that can be passed to base plot

Value

b - Maximum monolayer adsorption or adsorption maxima (mg/kg) k - Constant related to binding energy or the affinity coefficient for the nutrient, e.g., P (L/mg) MBC - Maximum buffering capacity of soil for the nutrient under consideration (L/kg)

References

Havlin, J.L., Tisdale, S.L., Nelson, W.L., Beaton, J.D., 2016. Phosphorus. In: Soil fertility and fertilizers. Pearson Education India, pp.160–198. Holford, I.C.R., Mattingly, G.E.G., 1976. Phosphate adsorption and plant availability of phosphate. Plant and Soil 44, 377–389. https://doi.org/10.1007/BF00015889 Langmuir, I., 1918. The adsorption of gases on plane surfaces of glass, mica, and platinum. Journal of American Chemical Society 40, 1361–1403. https://doi.org/10.1021/ja02242a004 Shirvani, M., Shariatmadari, H., Kalbasi, M., 2005. Phosphorus buffering capacity indices as related to soil properties and plant uptake. Journal of Plant Nutrition, 28, 537–550. https://doi.org/10.1081/PLN-200049235

Examples

with(data = df_sordes, Langmuir(W = 2, V = 20, Ci = Initial_conc, Cf = Equilibrium_conc))