The calculated results of the first-order rate equation are given in Table 2.
It is found that correlation coefficients values are low, showing the bad quality of linearization.
Additionally, the qe value acquired by this method is contrasted with the experimental value.
So the reaction cannot be classified as first-order.
One suggestion for the differences in experimental and theoretical qe values is that there is a time lag, possibly due to a boundary layer or external resistance controlling at the beginning of the sorption.
This time lag is also difficult to quantify. For this reason, it is necessary to use a trial and error method in order to obtain the equilibrium uptake