## 3 Results and Discussion
### Antibacterial Activity  
The antimicrobial properties of the synthesized materials were investigated to validate their safety thanks to the ability to inhibit the growth of pathogenic bacterial strains according to Kirby-Bauer method (Figure 1D): the zone where no growth occurred is called the inhibition zone. Additionally, according to the Kirby-Bauer method, the bacterium is defined as resistant (R) if the diameter of the inhibition zone is equal to or less than 17 mm; intermediate (I) if the diameter is between 18 and 22 mm; and sensitive (S) if it is equal to or greater than 23 mm. No inhibition zone was observed for all samples tested with the four different strains. Samples tested were not able to release some bioactive molecules  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**METALS**} & \multicolumn{8}{c}{**SAMPLE**} \\ \cline{2-9}  & **FG1** & **FG2** & **FG3** & **CPFG3** & **CPNT3** & **CPFG3N1** & **CPFG3N2** \\ \hline
**Al** & 484.62 & 114.58 & 634.1 & 960.1 & 69.52 & 203.08 & 120.3 \\ \hline
**As** & 10.66 & 11.04 & \textless{}2 & \textless{}2 & 5.3 & 5.95 & 54.2 \\ \hline
**B** & 115.72 & 199.79 & 60.4 & 153.2 & 4.94 & 3.92 & 160.4 \\ \hline
**Ba** & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 \\ \hline
**Cd** & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 \\ \hline
**Co** & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 \\ \hline
**Cr** & 11.54 & 5.21 & \textless{}2 & 12,85 & \textless{}2 & 3.82 & \textless{}2 \\ \hline
**Cu** & 4.64 & 3.69 & 4.1 & 4.43 & \textless{}2 & \textless{}2 & \textless{}2 \\ \hline
**Fe** & 244.92 & 70.22 & 39.84 & 154.3 & 13.76 & 2.94 & 161.6 \\ \hline
**Mn** & 5.34 & 4.58 & \textless{}2 & 22,4 & \textless{}2 & \textless{}2 & 47.8 \\ \hline
**Mo** & \textless{}2 & 2.26 & \textless{}2 & 31.64 & \textless{}2 & 12.9 & 225.21 \\ \hline
**Ni** & 39.31 & 39.23 & 9.47 & 5.7 & \textless{}2 & \textless{}2 & 7.67 \\ \hline
**Pb** & \textless{}2 & 2.82 & \textless{}2 & 10.1 & \textless{}2 & \textless{}2 & 3.45 \\ \hline
**Sb** & 9.18 & 10.79 & 2.6 & 5.79 & 2.02 & \textless{}2 & 6.09 \\ \hline
**Se** & 2.24 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & \textless{}2 & 7.49 \\ \hline
**Sn** & 10.39 & 4.8 & 2.13 & 16.62 & 3.24 & 7.02 & \textless{}2 \\ \hline
**Tl** & \textless{}2 & 2.33 & 2.66 & 23.5 & 4.55 & 2.22 & \textless{}2 \\ \hline
**V** & 24.01 & 11.02 & 63.1 & \textgreater{}400 & 40.77 & 65.39 & 62.99 \\ \hline
**Zn** & 18.14 & 17.92 & 6.83 & 13.32 & \textless{}2 & 4.53 & 6.03 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Results of metals release expressed in ppb.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{} & \multicolumn{8}{c}{**SAMPLE**} \\ \cline{2-9}  & **FG1** & **FG2** & **FG3** & **CPFG3** & **CPNT3** & **CPFG3N1** & **CPFG3N2** \\ \hline \(\text{PO}_{\text{4}}\text{3}^{-}\) & \textless{}0.5 & \textless{}0.5 & \textless{}0.5 & 0.741 & 0.821 & 2.41 & 7.1 \\ \hline
**P Tot** & 0.543 & 0.672 & 0.966 & 2 & 2.5 & 130 & 23.1 \\ \hline \(\text{NO}_{\text{3}}\text{-}\) & - & - & - & - & - & 0.7 & 0.7 \\ \hline
**N tot** & - & - & - & - & - & 9.516 & 1.672 \\ \hline
**K tot** & 169.56 & 210.56 & 130.64 & 25.21 & 44.54 & 155.99 & 44.1 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Results of nitrogen, phosphorus, and potassium released expressed in mg/L.