3.2 Coefficient of correlation

Almost given in every adsorption study, R2 shows the degree of variability of dependent variable which is explained by all independent variables. It ranges from 0 to 1, with values close to zero showing a perfect fit.

#### 3.3 Marquardt's percent standard deviation

Although not commonly used in adsorption kinetics analysis, this error function is a modification of geometric mean distribution. It is based on the number of degrees of freedom of a system [16].


qcal: calculated amount of adsorbate adsorbed onto adsorbent, qexp : experimental amount of adsorbate adsorbed, n: data points, p: number of parameters in each model.

Table 1. Common error functions.
