# Cationic and Anionic Dye Adsorption on a Natural Clayey Composite
## 3 Results and Discussion
### Adsorption Isotherms
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Isothermal**} & \multirow{2}{*}{**Constants**} & \multicolumn{4}{c}{**Adorbent (g/50 mL)**} \\ \cline{3-5}  & & **0.25** & **0.50** & **0.75** \\ \hline \multirow{3}{*}{Langmuir} & \(q_{m}[\text{mg/g}]\) & \(13.510\pm 2.873\) & \(1.311\pm 0.718\) & \(0.130\pm 0.107\) \\  & \(K_{L}[\text{L/mg}]\) & \(0.113\pm 0.092\) & \(0.440\pm 0.065\) & \(0.394\pm 0.016\) \\  & \(R^{2}\) & \(0.595\) & \(0.695\) & \(0.625\) \\  & \(R_{L}\) & \(0.371\pm 0.207\) & \(0.137\pm 0.084\) & \(0.131\pm 0.091\) \\ \hline \multirow{3}{*}{Freundlich} & \(K_{F}\left[(\text{mg/g})/(\text{mg/L})^{n}\right]\) & \(2.016\pm 1.036\) & \(0.877\pm 0.755\) & \(0.559\pm 0.502\) \\  & \(n\) & \(0.857\pm 0.198\) & \(0.335\pm 0.016\) & \(0.297\pm 0.028\) \\  & \(R^{2}\) & \(0.705\) & \(0.835\) & \(0.528\) \\ \hline \multirow{3}{*}{Temkin} & \((RT/b_{t})\) [J/mol] & \(8.609\pm 1.310\) & \(10.902\pm 1.731\) & \(8.760\pm 4.802\) \\  & \(R_{T}\) & \(285.062\pm 51.632\) & \(225.104\pm 31.278\) & \(280.145\pm 43.163\) \\ \cline{1-1}  & \(A_{T}[\text{L/g}]\) & \(0.885\pm 0.053\) & \(0.916\pm 0.069\) & \(0.894\pm 0.185\) \\ \cline{1-1}  & \(R^{2}\) & \(0.913\) & \(0.906\) & \(0.670\) \\ \hline \multirow{3}{*}{Dubinin–Radushkevich} & \(q_{m}[\text{mg/g}]\) & \(18.519\pm 4.054\) & \(27.805\pm 10.105\) & \(18.503\pm 8.765\) \\ \cline{1-1}  & \(K_{DR}\left[\text{mol}^{2}/\text{kJ}^{2}\right]\) & \(1.48\times 10^{-6}\pm\) & \(1.40\times 10^{-6}\pm\) & \(1.35\times 10^{-6}\pm\) \\ \cline{1-1}  & \(K_{DR}\left[\text{mol}^{2}/\text{kJ}^{2}\right]\) & \(2.96\times 10^{-7}\) & \(2.07\times 10^{-7}\) & \(1.35\times 10^{-7}\) \\ \cline{1-1}  & \(E[\text{kJ/mol}]\) & \(0.580\pm 0.043\) & \(0.598\pm 0.040\) & \(0.609\pm 0.043\) \\ \cline{1-1}  & \(R^{2}\) & \(0.881\) & \(0.917\) & \(0.421\) \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Characteristic parameters of the adsorption isotherms model after it was fitted with the experimental data obtained with the ADY—Drimaren Yellow Dye CL-2R. Adsorbate concentration 50 mg/L. pH = 2. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Isothermal**} & \multirow{2}{*}{**Parameter**} & \multicolumn{2}{c}{**Adorbent (g/50 mL)**} \\ \cline{3-5}  & & **0.25** & **0.50** & **0.75** \\ \hline \multirow{3}{*}{Langmuir} & \(q_{m}[\text{mg/g}]\) & \(10.614\pm 2.354\) & \(6.146\pm 0.693\) & \(6.013\pm 1.747\) \\  & \(K_{L}[\text{L/mg}]\) & \(0.290\pm 0.084\) & \(0.511\pm 0.036\) & \(0.390\pm 0.165\) \\  & \(R^{2}\) & \(0.963\) & \(0.991\) & \(0.991\) \\  & \(R_{L}\) & \(0.187\pm 0.005\) & \(0.103\pm 0.070\) & \(0.178\pm 0.110\) \\ \hline \multirow{3}{*}{Freundlich} & \(K_{F}\left[(\text{mg/g})/(\text{mg/L})^{n}\right]\) & \(2.283\pm 0.519\) & \(1.906\pm 0.053\) & \(1.540\pm 0.244\) \\  & \(n\) & \(1.994\pm 0.312\) & \(2.156\pm 0.052\) & \(1.993\pm 0.358\) \\  & \(R^{2}\) & \(0.875\) & \(0.995\) & \(0.834\) \\ \hline \multirow{3}{*}{Temkin} & \((RT/b_{t})\) [J/mol] & \(2.842\pm 0.840\) & \(1.498\pm 0.160\) & \(1.176\pm 0.130\) \\  & \(b_{T}\) & \(863.494\pm 362.310\) & \(1647.649\pm 198.301\) & \(2086.756\pm 259.348\) \\ \cline{1-1}  & \(A_{T}[\text{L/g}]\) & \(1.582\pm 0.149\) & \(3.772\pm 0.043\) & \(4.188\pm 0.008\) \\ \cline{1-1}  & \(R^{2}\) & \(0.718\) & \(0.955\) & \(0.946\) \\ \hline \multirow{3}{*}{Dubinin–Radushkevich} & \(q_{m}[\text{mg/g}]\) & \(7.838\pm 1.650\) & \(4.698\pm 0.706\) & \(3.889\pm 0.452\) \\ \cline{1-1}  & \(K_{DR}\left[\text{mol}^{2}/\text{kJ}^{2}\right]\) & \(4.81\times 10^{-7}\pm\) & \(2.06\times 10^{-7}\pm\) & \(2.65\times 10^{-7}\pm\) \\ \cline{1-1}  & \(K_{DR}\left[\text{mol}^{2}/\text{kJ}^{2}\right]\) & \(1.93\times 10^{-8}\) & \(2.08\times 10^{-8}\) & \(4.10\times 10^{-8}\) \\ \cline{1-1}  & \(E[\text{kJ/mol}]\) & \(1.019\pm 0.021\) & \(1.558\pm 0.072\) & \(1.373\pm 0.095\) \\ \cline{1-1}  & \(R^{2}\) & \(0.565\) & \(0.  
of each solution. The solution's temperature had increased 0.5, 0.6, and 3.3 degrees Celsius, in the container with water, with water+clay, and with water+clay+dye, respectively.