nonlinear_freundlich: Non-linear Freundlich Model

In AdsorpR: Adsorption Isotherm Models

Non-linear Freundlich Model

Description

The non-linear Freundlich isotherm model is an empirical equation describing adsorption on heterogeneous surfaces. It assumes that adsorption sites are not uniform and that binding energy decreases exponentially with surface coverage.

The model is given by:

Q = K_f \cdot C_e^{1/n}

where Q is the amount adsorbed, C_e is the equilibrium concentration, K_f is the Freundlich constant (adsorption capacity), and n is the heterogeneity index (indicating adsorption intensity).

This function fits the Freundlich model using non-linear least squares regression.

Usage

nonlinear_freundlich(Ce, Qe)

Arguments

Ce	Numeric vector of equilibrium concentrations.
Qe	Numeric vector of amount adsorbed.

Value

A named list of Freundlich parameters and model details, including parameter estimates, model diagnostics, and a diagnostic plot.

See Also

Other nonlinear models: nonlinear_bet(), nonlinear_langmuir(), nonlinear_temkin()

Examples

Ce <- c(0.5, 1, 2, 4, 6, 8)
Qe <- c(0.3, 0.8, 1.6, 2.4, 2.9, 3.2)
result <- nonlinear_freundlich(Ce, Qe)
print(result$`Freundlich Kf`)
print(result$`Freundlich n`)
print(result$AIC)
print(result$`Pseudo R2`)
print(result$Plot)

AdsorpR documentation built on April 12, 2025, 1:23 a.m.