## 4 Conclusions  
This work presents a method of synthesis of bio-based porous polymer microspheres with the use of terpene compounds and vegetable oils as substrates. The obtained polymers were characterized using chemical and instrumental methods, which allowed the structural and chemical differences of these materials to be determined. The citral- and limonene-based polymers possessed well-developed porous structures (SBET 428 and 509 m\({}^{2}\)/g) with more uniform pores compared to the oil-based materials, with pores of a wider range of diameters and specific surface areas not exceeding 100 m\({}^{2}\)/g. Furthermore, the thermal resistance of the polymers was diversified. P-DVB, Lo-DVB, and Ao-DVB were less thermally stable and should not be utilized above 100 \({}^{\circ}\)C, while C-DVB, L-DVB, and Ro-DVB can be safely employed even up to 270-300 \({}^{\circ}\)C. Chemical analysis proved the presence of acidic groups on the surface of the studied polymers. The oil-based materials possessed about 21-44 mg/g of free carboxylic groups and the terpene-based ones possessed only 4-9 mg/g. This surface acidity together with the porosity turned out to have a particularly significant influence on the sorption process of selected test compounds. The presence \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Sorbent Type** & **Drug** & **Matrix** & **Eluent** & **\% of Recovery** & **Ref.** \\ \hline pDVB & Salicylic acid & water & MeOH & 4.6 & \\ pDVB-SO\({}_{3}\)H & Salicylic acid & water & H\({}_{2}\)O and EtOH & & [38] \\ SAPA-MAA & & & H\({}_{2}\)O and EtOH & & \\ (SiO\({}_{2}\)-Al\({}_{2}\)O\({}_{3}\)-Propyl & Salicylic acid & water & 0.01 mol/L NaOH and & \textless{}12.5 & \\ amine-Methyl methacrylate) & & & 35\% EtOH & & \\ pDVB & Aspirin & water & MeOH & 35 & \\ DVB-GMA(75-25)-H\({}_{2}\)SO\({}_{4}\) & & & 17 & \\ Poly(4 VP-14 DVB & Ibuprofen & water & MeOH & \textless{}70 & \\ pDVB & Ibuprofen & water & MeOH & 4.8 & \\ pDVB-SO\({}_{3}\)H & & & & 16.2 & \\ aqueous biphasic systems (ABS) & Paracetamol & Pharmaceutical waste & water & 80–100 & [59] \\ VBC-DVB & & acetonitrile 0.1 mol/L & methanol: glacial & & \\ poly(chloromethylstyrene-co-divinylbenzene (PVBC-DVB) & & aqueous NaOH (9:1, \(v/v\)) & acetic acid (8:2, \(v/v\)) & \\ amino-functionalized silica gels & & Milk & methanol–acetic acid & 64–82 & \\ covered with MAA—EGDMA & & blood & (4:1, \(v/v\)). The & 67–78 & [61] \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Comparison table of drug recoveries reported in the literature. of functional groups capable of forming hydrogen bonds or acid-base complexes with the adsorbates significantly affected the uptake from the solution, and consequently, the recovery of adsorbed compounds. However, for a comprehensive explanation of the obtained results, it was also necessary to take into account the properties of adsorbates and the processes that may occur in the solution and at the solution-polymer interface. The highest sorption efficiency towards dichlorophenol and trichlorophenol was achieved by C-DVB and L-DVB; the recoveries for these phenols were in the range of 70-100% and 60-80%, respectively. Results at this level were maintained even for 500 mL samples in the fifth concentration cycle. The efficiency of Ro-DVB was lower due to the less developed porosity. Although, the recoveries for di- and trichlorophenol were 80-90% and 80-85%, respectively, they were only valid for the 100 and 200 mL samples. The lowest recovery results (3-45%) were obtained for phenol because of its hydrophilic nature and good solubility in water. All the presented polymers were very efficient in the removal of ibuprofen (25-70%) and somewhat less effective in the removal of paracetamol (5-37%). A 35% recovery of salicylic acid was reached only by the LO-DVB polymer. The undoubtedly advantage of the presented bio-based polymers is their good regeneration potential and the possibility of reuse without losing the recovery efficiency.