## 3 Results and Discussion
### Modeling of Sorption Isotherms--Influence of pH  
The sorption parameters of the three types of sorbents fitted to the linear, Freundlich, and Langmuir isotherms are shown in Table 6 for IMT and Table 7 for CRZ, respectively. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multirow{2}{*}{**c\({}_{\text{0}}\), mg/L**} & \multicolumn{6}{c}{**First Stage**} & \multicolumn{6}{c}{**Second Stage**} & \multicolumn{6}{c}{**Third Stage**} \\ \cline{3-10}  & & \(k_{\text{P1}}\) & \(k_{\text{P2}}\) & \(\boldsymbol{C_{1}}\) & \(k_{\text{P2}}\) & \(\boldsymbol{R^{2}}\) & \(\boldsymbol{C_{2}}\) & \(k_{\text{P3}}\) & \(\boldsymbol{R^{2}}\) & \(\boldsymbol{C_{3}}\) \\  & & \(\mu\)g/g min\({}^{1/2}\) & & & \(\mu\)g/g min\({}^{1/2}\) & & & \(\mu\)g/g min\({}^{1/2}\) & & \\ \hline \multirow{3}{*}{suspended TiO\({}_{2}\)} & 5 & 2.484 & 0.9731 & 5.757 & 0.1139 & 0.8928 & 10.73 & 0.1018 & 0.9800 & 10.92 \\  & 15 & 3.257 & 0.9751 & 8.884 & 0.5956 & 0.9853 & 12.35 & 0.2395 & 0.9997 & 19.34 \\  & 25 & 3.475 & 0.9577 & 9.525 & 0.4854 & 0.9901 & 15.42 & 0.4181 & 0.9788 & 17.096 \\ \hline \multirow{3}{*}{TiO\({}_{2}\)-GF} & 5 & 0.7496 & 0.9828 & 7.675 & 1.6248 & 0.9915 & 2.012 & 0.0121 & 0.8842 & 27.19 \\  & 15 & 12.317 & 0.9942 & 4.801 & 4.8479 & 0.9873 & 44.82 & 0.1761 & 0.9614 & 115.88 \\  & 25 & 12.738 & 0.9840 & 40.46 & 8.4091 & 0.9867 & 35.57 & 0.0867 & 0.9994 & 166.9 \\ \hline \multirow{3}{*}{TiO\({}_{2}\)/ CNT-GF} & 5 & 1.732 & 0.9623 & 4.491 & 2.7714 & 0.9100 & 8.461 & 0.0018 & 0.8187 & 32.33 \\  & 15 & 5.338 & 0.9557 & 18.016 & 5.5006 & 0.9850 & 15.58 & 0.0402 & 0.9712 & 67.58 \\ \cline{1-1}  & 25 & 5.018 & 0.9373 & 17.199 & 10.283 & 0.9694 & 51.27 & 0.1127 & 0.9920 & 102.87 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Intraparticle diffusion model for IMT. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**IMT**} & \multirow{2}{*}{**Initial**} & \multirow{2}{*}{\(\boldsymbol{q_{e,exp}}\), \(\mu\)g/g} & \multicolumn{6}{c}{**Pseudo-First-Order**} & \multicolumn{6}{c}{**Pseudo-Second-Order**} \\ \cline{3-10}  & & & \(q_{e,calc}\), \(\mu\)g/g & \(k_{1}\), min\({}^{-1}\) & \(R^{2}\) & \(\boldsymbol{q_{e,calc}}\), \(\mu\)g/g & \(k_{2}\), g/ug min & \(R^{2}\) \\ \hline \multirow{2}{*}{suspended TiO\({}_{2}\)} & 5 & 14.62 & 8.47 & 0.0059 & 0.9488 & 14.90 & \(2.03\times 10^{-4}\) & 0.9990 \\  & 15 & 28.40 & 8.50 & \(5\times 10^{-5}\) & 0.6238 & 29.67 & \(4.26\times 10^{-4}\) & 0.9981 \\  & 25 & 32.47 & 10.76 & \(3\times 10^{-5}\) & 0.6731 & 34.25 & \(3.13\times 10^{-4}\) & 0.9969 \\ \hline \multirow{3}{*}{TiO\({}_{2}\)-GF} & 5 & 27.37 & 4.73 & 0.0002 & 0.6430 & 28.57 & \(8.36\times 10^{-4}\) & 0.9989 \\  & 15 & 118.50 & 6.52 & 0.0004 & 0.6385 & 125 & \(2.96\times 10^{-4}\) & 0.9999 \\  & 25 & 168.25 & 8.94 & 0.0002 & 0.6516 & 174.44 & \(1.67\times 10^{-4}\) & 0.9995 \\ \hline \multirow{3}{*}{TiO\({}_{2}\)/ CNT-GF} & 5 & 32.35 & 4.87 & 0.0003 & 0.5734 & 36.76 & \(1.72\times 10^{-4}\) & 0.9792 \\  & 15 & 68.18 & 8.23 & 0.0002 & 0.6100 & 85.47 & \(4.20\times 10^{-4}\) & 0.8151 \\ \cline{1-1}  & 25 & 104.65 & 10.48 & 0.0002 & 0.6309 & 161.29 & \(1.05\times 10^{-5}\) & 0.5285 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Sorption kinetic parameters for IMT.