## 3 Results and Discussion
### AHMPD Degradation Studies with P3 and P4 Polymers as Photosensitizers in Industrial WWTP Samples  
To evaluate the actual degradation capacity of AHMPD in real samples, two effluent samples from the IWWTP were utilized. The detected concentrations of the pesticide were abnormally high in both samples, at 0.027 ppm and 0.016 ppm, respectively. These concentrations were measured by GC-MS/MS according to the analytical data provided by the IWWTP manager. These dates correspond to high-production campaigns for the agri-food company.  
Based on the previously obtained results, degradation tests of AHMPD were conducted using both real water samples. Photosensitizers P3 and P4 were employed for these tests, with experiments performed with the sample brought at pH = 11. The AHMPD analytical results of the samples are presented in Table 3.  
The experiments were conducted in quintupplicate for each of the samples, resulting in a total of 20 experiments, as the degradation kinetics for P3 and P4 were evaluated for each sample. In all cases, the kinetic constants were calculated and were also found in first-order kinetics. Additionally, the percentage of AHMPD degradation was calculated and monitored by UV-Vis at the absorption maximum of 270 nm. Table 3 presents the degradation percentage, accompanied by the standard deviation. Figure 7 shows a comparison of the AHMPD degradation rates between the initial control samples used for the first-order kinetic calculations of P2, P3, and P4 and the experiments conducted on the real samples using P3 and P4.  
The degradation percentages in industrial effluent samples are comparable to those observed in the initial tests for kinetic calculations for both P3 and P4. Notably, P4 also exhibits higher degradation percentages. These results are signific  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Photosensitizer** & **Sample 1** & **Sample 2** \\ \hline \multirow{2}{*}{Darkness} & Concentration of AHMPD at t = 0 h & 0.027 ppm & 0.016 ppm \\  & Degradation at t = 48 h & 0\% & 0\% \\ \hline \multirow{2}{*}{P3} & \(k_{\text{obs}}\) (10\({}^{-4}\) h\({}^{-1}\)) & 289 \(\pm\) 12 & 292 \(\pm\) 7 \\  & Degradation at t = 48 & 75 \(\pm\) 2\% & 75 \(\pm\) 1\% \\ \multirow{2}{*}{P4} & \(k_{\text{obs}}\) (10\({}^{-4}\) h\({}^{-1}\)) & 391 \(\pm\) 10 & 383 \(\pm\) 8 \\  & Degradation at t = 48 & 85 \(\pm\) 1\% & 84 \(\pm\) 1\% \\ \hline \hline \end{tabular}
\end{table}
Table 3: Degradation rates for AHMPD with P3 and P4 in Sample 1 and Sample 2, pH = 11.  
Figure 7: Comparison of the AHMPD degradation rate between the initial control samples for the kinetic calculations conducted for P2, P3, and P4 and for the experiments in both real samples of P3 and P4.  
degradation monitored via UV-Vis in both real samples, as a typical issue with IWWTP effluent samples is the interference in spectroscopy due to the possible presence of organic matter; however, the pH = 11 of the reaction medium could favor the elimination of these potential interferences. Regarding the reaction kinetics for these samples, they were also slow, with reaction times similar to those observed in previous experiments at \(5\times 10^{-6}\) M (equivalent to 625 ppm). It is important to highlight that these two samples exhibit high concentrations of this pesticide. Although the current legislation does not mandate the company to conduct such analyses for determining EPs, they occasionally do. Consequently, the frequency of AHMPD presence in the effluent waters of the IWWTP and the underlying reasons remain unclear, likely due to the pesticide's use at specific times in the citrus farms supplying the company.