## 3 Results and Discussion  
The kinetic experimental results on the adsorption of acetaminophen and ibuprofen from ultrapure water onto the activated carbon (GPP20) and onto the polymeric resin (Sepabeads SP207) are represented in Figures 1 and 2. Meanwhile, Figures 3 and 4 represent the corresponding experimental kinetic results from waste water. In these figures, fittings to the kinetic models here considered (Equations (3) and (4)) are shown together with experimental results whereas the corresponding fitted parameters are depicted in Table 4. In Figures 1-4, it is evidenced that \(q_{\rm t}\) increases with \(t\) until reaching the equilibrium, and then \(q_{\rm t}\) remains stable throughout time. As it may be seen in these figures, although experimental results were slightly better described by the pseudo-second equation, both the here used kinetic models may be considered appropriate, which is confirmed by the \(R^{2}\) (\(R^{2}\geq 0.98\)). As for the corresponding fitted kinetic constants in Table 4, the adsorption of the here studied pharmaceuticals was faster onto the activated carbon than onto the polymeric resin, which must be mainly related to the larger particle size of the latter (Table 1). On the other hand, the adsorption velocity was mostly unaffected by the matrix, with similar kinetic constants for the adsorption from ultrapure and waste water. Then, for the subsequent equilibrium experiments, the \(t_{\rm eq}\) values for the adsorption onto GPP20 and onto Sepabeads SP207 were 48 and 72 h, respectively. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multirow{2}{*}{**Parameters**} & \multicolumn{6}{c}{**Acetaminophen**} & \multicolumn{6}{c}{**Ibuprofen**} \\ \cline{3-10}  & & \multicolumn{2}{c}{**GPP20**} & \multicolumn{2}{c}{**SP20**} & \multicolumn{2}{c}{**GPP20**} & \multicolumn{2}{c}{**SP20**} \\ \cline{3-10}  & & **UPW** & **WW** & **UPW** & **WW** & **UPW** & **WW** & **UPW** & **WW** & **UPW** & **WW** \\ \hline \multirow{4}{*}{**Methods**} & \(k_{1}\) (min\({}^{-1}\)) & 0.008 \(\pm\) 0.0007 & 0.0093 \(\pm\) 0.0006 & 0.0021 \(\pm\) 0.0002 & 0.0019 \(\pm\) 0.0002 & 0.0105 \(\pm\) 0.0009 & 0.0085 \(\pm\) 0.0004 & 0.0016 \(\pm\) 0.0001 & 0.0033 \(\pm\) 0.0003 \\  & \(q_{t}\) (mg s\({}^{-1}\)) & 1806.0 \(\pm\) 2.48 & 196.2 \(\pm\) 2.56 & 3.95 \(\pm\) 0.09 & 5.39 \(\pm\) 0.11 & 99.955 \(\pm\) 1.63 & 136.60 \(\pm\) 2.04 & 152.42 \(\pm\) 0.27 & 156.3 \(\pm\) 0.23 \\  & \(R^{2}\) & 0.9914 & 0.9925 & 0.9800 & 0.9832 & 0.9872 & 0.9914 & 0.9898 & 0.9849 \\  & \(S_{\rm W}\) & 6.59 & 6.76 & 0.22 & 0.27 & 4.35 & 5.04 & 0.63 & 0.73 \\ \hline \multirow{4}{*}{**Methods**} & \(k_{2}\) (g mg\({}^{-1}\) min\({}^{-2}\)) & 0.00008 \(\pm\) 0.00001 & 0.00006 \(\pm\) 0.00001 & 0.00069 \(\pm\) 0.00005 & 0.00045 \(\pm\) 0.00033 & 0.00015 \(\pm\) 0.00001 & 0.00006 \(\pm\) 0.00004 & 0.00013 \(\pm\) 0.00001 & 0.00031 \(\pm\) 0.00003 \\  & \(q_{t}\) (mg s\({}^{-1}\) min\({}^{-2}\)) & 191.2 \(\pm\) 2.99 & 210.30 \(\pm\) 3.40 & 3.44 \(\pm\) 0.05 & 5.96 \(\pm\) 0.08 & 105.60 \(\pm\) 1.49 & 146.50 \(\pm\) 1.75 & 174.01 \(\pm\) 0.32 & 16.77 \(\pm\) 0.27 \\  & \(R^{2}\) & 0.9916 & 0.9913 & 0.9961 & 0.9958 & 0.9926 & 0.991 & 0.9927 & 0.9911 \\  & \(S_{\rm W}\) & 6.48 & 7.30 & 0.10 & 0.13 & 3.29 & 3.39 & 0.51 & 0.55 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Kinetic parameters obtained from the fittings of experimental results on the adsorption of acetaminophen and ibuprofen from ultrapure water (UPW) and from waste water (WW) to the pseudo-sector and to the pseudo-second order equations. Figure 1: Kinetic results on the adsorptive removal of acetaminophen from ultrapure water by adsorption onto (**a**) the activated carbon GPP20 and (**b**) the polymeric resin Sepabeads SP207. Experimental results are shown together with fittings to the pseudo-first and pseudo second order kinetic equations. Error bars stand for standard deviation of three experimental replications. Note: for a better visualization of fittings, the scale of axis Y has been adjusted to results.