## 4 Conclusions  
Argan nutshells were converted into highly porous carbons via two-step activation: in the first step, the biochar was obtained, and in the second step, the biochar was activated with KOH. The experimental design used allowed the conclusion that the sample impregnated at a Biochar/KOH ratio of 1:2 and activated at 800 \({}^{\circ}\)C for 1 h presented the higher surface area and developed porosity. Thus, this sample, ACK carbon, was selected for further characterization and applied as an adsorbent of diclofenac (DCF) and paroxetine (PARX) present in synthetic solutions. Textural (N\({}_{2}\) adsorption isotherms and SEM-EDS) and chemical (pH\({}_{\text{PZC}}\), FTIR, XPS, and TPD) surface properties of ACK porous carbon were determined and compared to that of a commercial carbon, CC, used as a benchmark. ACK carbon presented a higher surface area and micropore volume (1624 m\({}^{2}\) g\({}^{-1}\), 0.40 cm\({}^{3}\) g\({}^{-1}\)) than the CC carbon (1030 m\({}^{2}\) g\({}^{-1}\), 0.30 cm\({}^{3}\) g\({}^{-1}\)), but the maximum uptake capacities of DCF (214-217 mg g\({}^{-1}\)) and PARX (260-275 mg g\({}^{-1}\)) obtained from the Sips isotherm model were comparable among the two carbons. Besides the typical \(\pi\)-\(\pi\) interactions, H-bonds with the electronegative atoms (F, N, and O) of the adsorbate molecules and the electropositive H of the oxygen functional groups were pointed out as the most probable mechanisms for the adsorption onto ACK porous carbon, given the fact that this carbon presented a surface richer in -OH phenolic groups and carboxyl groups -COOH. The electrostatic attraction was also considered, particularly for the DCF molecule with CC carbon. The pore size might have also been critical, since CC carbon presented more supermicropores (0.7-2 nm), which are usually more favorable for the adsorption of pharmaceutical molecules. Argan nutshell-derived carbons activated with KOH achieve higher uptake capacities of DCF and PARX than the biomass-based carbons activated with H\({}_{3}\)PO\({}_{4}\), because KOH allows obtaining carbons with higher microporosity. Based on the results of this study, organ nutshells are valid precursors for developing porous carbons with a high adsorption capacity of DCF and PARX molecules. **Supplementary Materials:** The following supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/app12157607/s1](https://www.mdpi.com/article/10.3390/app12157607/s1)]([https://www.mdpi.com/article/10.3390/app12157607/s1](https://www.mdpi.com/article/10.3390/app12157607/s1)). Figure S1. Molecular structures of the pharmaceutical compounds used in the present study. Figure S2. Calibration curves of DCF and PARX determined by UV-Vis spectrophotometry. Figure S3. N\({}_{2}\) adsorption-desorption isotherms of ACK and CC carbon samples. Figure S4. TGA curves of ANS biomass, biochar, ACK, and CC under argon atmosphere. Figure S5. XPS peak fitted profiles of C 1s and O 1s regions of ACK and CC carbons. Figure S6. TPD spectra of the carbons: (A) CO and (B) CO\({}_{2}\) evolution. Figure S7. SEM image of CC sample with magnification 1500\(\times\) and the corresponding EDS spectrum [29]. Table S1. Equations of the kinetic models and isotherm models used in the present work. **Author Contributions:** Conceptualization, A.M., O.B. and M.B. ; methodology, A.M., Z.K., M.B., O.S.G.P.S. and A.M.B.D.R. ; validation, O.B., A.B., R.F., M.B., I.M., N.L. and M.V. ; formal analysis, A.M., Z.K., M.B., O.S.G.P.S. and A.M.B.D.R. ; investigation, A.M., M.B., I.M., M.V., O.S.G.P.S. and A.M.B.D.R. ; resources, O.B., A.B., R.F., M.B., N.L., O.S.G.P.S., A.M.B.D.R. and I.F. ; writing--original draft preparation, A.M. and M.B. ; writing--review and editing, A.M., O.B., M.B., I.M., N.L., M.V., O.S.G.P.S., A.M.B.D.R. and I.F. ; visualization, A.M. and M.B. ; supervision, O.B., M.B. and I.F. ; and funding acquisition, O.B., N.L. and I.F. All authors have read and agreed to the published version of the manuscript.