## 3 Results and Discussion
### Investigation of Structure Modification after Composite Beads' Recovery  
Finally, to evaluate the integrity of the material for potential reuse, the 3-RM system was analyzed after each procedure. In this respect, the structure and composition of the material upon contact with the contaminant (2_A_-DCFA) were verified by FTIR (spectra \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sample Code**} & **adsorbent** & **\multirow{2}{*}{**pH**} & **TOC\({}_{\text{final}}\)** & **adsorption Capacity \({}^{*}\)** & **adsorbed Amount** \\  & **Amount (mg)** & & **(mg C/L)** & **(mg C/g Adsorbent)** & **(\%)** \\ \hline
1-Ref & 40.5 & 3.70 & 48.54 & / & / \\
1-RM & 40.7 & 3.67 & 47.23 & / & / \\
2-Ref & 39.6 & 3.64 & 47.99 & / & / \\
2-RM & 40.4 & 3.70 & 49.07 & / & / \\
3-Ref & 40.1 & 3.80 & 47.83 & / & / \\
3-RM & 41.0 & 3.75 & **41.85** & 1.65 & 9.71 \\ \hline  & \multicolumn{4}{c}{\({}^{*}\)Calculated as (TOC\({}_{\text{initial}}\)-TOC\({}_{\text{final}}\))\(\cdot\)V\({}_{\text{solution}}\)/m\({}_{\text{adsorbent}}\) where TOC\({}_{\text{initial}}\) is 46.35 mg C/L and V\({}_{\text{solution}}\) is 0.015 L\({}_{\text{s}}\) **} \\  & \multicolumn{4}{c}{\({}^{**}\)Calculated as (TOC\({}_{\text{initial}}\)-TOC\({}_{\text{final}}\))\(\cdot\)100/TOC\({}_{\text{initial}}\), where TOC\({}_{\text{initial}}\) is 46.35 mg C/L.} \\ \end{tabular}
\end{table} 
Table 4: Adsorption test results as function of amount and type of beads. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & **adsorbent** & **TOC\({}_{\text{initial}}\)** & **adsorption/** & **adsorbed/** \\  & **Amount (mg)** & **(mg C/L)** & **(mg C/g Adsorbent)** & **Oxidation Capacity \({}^{*}\)** & **Oxidized Amount vs.** \\ \hline
2,4 DCFA & +H\({}_{2}\)O\({}_{2}\) & - & 46.64 & - & - \\ RM & +H\({}_{2}\)O\({}_{2}\) & 40.4 & 1.34 & - & - \\
3-Ref + & +H\({}_{2}\)O\({}_{2}\) & 40.2 & 42.03 & 5.73 & 9.88 \\
2,4 DCFA & +H\({}_{2}\)O\({}_{2}\) & 39.8 & 40.67 & 7.50 & 12.80 \\ \hline  & \multicolumn{4}{c}{\({}^{*}\)Calculated as (TOC\({}_{\text{initial}}\)-TOC\({}_{\text{final}}\))\(\cdot\)V\({}_{\text{solution}}\)/m\({}_{\text{adsorbent}}\), where TOC\({}_{\text{initial}}\) is 46.64 mg C/L and V\({}_{\text{solution}}\) is 0.050 L; ** calculated as (TOC\({}_{\text{initial}}\)-TOC\({}_{\text{final}}\))\(\cdot\)100/TOC\({}_{\text{initial}}\), where TOC\({}_{\text{initial}}\) is 46.64 mg C/L.} \\ \end{tabular}
\end{table} 
Table 5: Results of oxidation tests for the 3-RM/3-Ref series compared to RM alone. given in Figure 5). Although no critical changes in the copolymer structures are observed either in the case of oxidation or adsorption processes, some essential bands appear due to the presence of 2,4-DCFA in the beads. Figure 5A shows that -OH groups appear following the adsorption/oxidation processes (3550-3650 cm\({}^{-1}\)). These can be assigned to the carboxyl group in 2,4-DCFA. The sharp band appearing at 600 cm\({}^{-1}\) is associated with the presence of -C-Cl bonds in 2,4-DCFA. In addition, bands previously associated with sulfated ions from the redox system and S=O in DMSO (950 cm\({}^{-1}\) and 1030 cm\({}^{-1}\), respectively) disappear due to the intense purification procedure performed before adsorption and oxidation tests. Last but not least, the characteristic bands of the copolymer at 3380 cm\({}^{-1}\) (O-H), 1732 cm\({}^{-1}\) (C=O), 2244 cm\({}^{-1}\) (C\(\equiv\)N), and 2940 cm\({}^{-1}\) (stretching -CH\({}_{2}\)) are more intense but with no specific modifications. The band at 1455 cm\({}^{-1}\) (in plane deformation of the aliphatic CH\({}_{2}\) groups in the backbone) that was more affected by the presence of RM is more intense after adsorption and oxidation. This could mean that the interactions with the copolymer backbone have diminished due to RM implication in the adsorption/oxidation processes of 2,4-DCFA.