\[\frac{x}{m} = K_F\,c^{1/n},\qquad \lg\frac xm = \lg K_F + \frac1n\lg c\]
含义Meaning
经验吸附等温式，适合不均匀表面上的中等覆盖度，常用于活性炭从溶液中吸附有机物、土壤吸附污染物。
An empirical isotherm for heterogeneous surfaces at moderate coverage, widely used for activated carbon adsorbing organics from solution and soils adsorbing pollutants.
符号说明Symbols
| 符号Symbol | 含义 Meaning | 单位 Unit |
|---|---|---|
| \(x/m\) | 单位质量吸附剂的吸附量amount adsorbed per mass of adsorbent | mg·g⁻¹ |
| \(K_F, n\) | 经验常数（n > 1 表示有利吸附）empirical constants (n > 1 favourable) |
推导Derivation
可视为吸附热随覆盖度呈对数下降的表面上朗缪尔等温式的叠加。
It corresponds to a superposition of Langmuir isotherms with a logarithmic distribution of adsorption energies.
取对数作直线，斜率 1/n。
A log–log plot is linear with slope 1/n.
适用条件与局限Assumptions & limitations
没有饱和极限，不适合高覆盖度；参数无明确物理意义。
No saturation limit; parameters lack clear physical meaning.