## 3 Results and Discussion
### Characteristics of Anb/C and Anb/AgNP/C Composites
The fine nanoparticles, in comparison to larger nitrogenous base molecules, diffuse faster into the surface of activated carbon and fill the active sites, also those not available for adenosine. At 10 and 25 \({}^{\circ}\)C, due to the lower kinetic energy of nanoparticles, they stay in the solution longer and inhibit adenosine molecules diffusion into suitable carbon pores. Additionally, any transformation of silver nanoparticles into aggregates can lead to a blocking of access for adenosine to some carbon  
Figure 7: Comparison of adenosine adsorption kinetics from the one-component (**A**,**B**) and bicomponent solutions (**C**,**D**) on the activated carbon RIAA at 10, 25, and 40 \({}^{\circ}\)C. Comparison of silver nanoparticles adsorption kinetics from the two-component solutions on RIAA in the range time 1-1200 min at various temperatures. The lines correspond to the fitted multiexponential equation. pores. Graphically, the progress of adenosine adsorption from the one-component and two-component solutions at various temperatures is presented in Figure 9A-D.  
Figure 8: Comparison of adenosine adsorption kinetics from the one-component and bicomponent solutions on the activated carbon RIAA at 10 \({}^{\circ}\)C (**A**), 25 \({}^{\circ}\)C (**B**), and 40 \({}^{\circ}\)C (**C**). The lines correspond to the fitted multiexponential equation. Figure 9: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Efficiency/Temperature**} & \multicolumn{4}{c}{**Time (min)**} \\ \cline{2-7}  & \multicolumn{2}{c}{**10 \({}^{\circ}\)C**} & \multicolumn{2}{c}{**25 \({}^{\circ}\)C**} & \multicolumn{2}{c}{**40 \({}^{\circ}\)C**} \\ \cline{2-7}  & **Anb/C** & **Anb/AgNP/C** & **Anb/C** & **Anb/AgNP/C** & **Anb/C** & **Anb/AgNP/C** \\ \hline
**25\%** & 93 & 197 & 55 & 110 & 45 & 84 \\ \hline
**50\%** & 222 & 555 & 138 & 387 & 121 & 228 \\ \hline
**75\%** & 470 & 1200 & 296 & 920 & 258 & 478 \\ \hline
**95\%** & 970 & - & 666 & - & 560 & - \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of times needed to achieve adsorption efficiencies at various temperatures. The mechanism of adenosine adsorption on the activated carbon RIAA was based on the \(\pi\)-\(\pi\) interactions of aromatic rings and to a lesser extent of the possible electrostatic attraction forces (between charged moieties of the solid surface and hydroxy or protonated amino groups of the adsorbate), and the hydrogen bonds. Based on the estimated values of the adsorption activation energy for the one-and two-component systems (22.56/22.7 and 14.87/13.42 kJ/mol, respectively) one can suggest that the presence of the Ag nanophase significantly weakened interactions between adenosine and activated carbon. Based on relative standard deviations SD(c)/c\({}_{\rm o}\), the determination of the optimal number of exponents of the multiexponential equation required to optimize kinetic data was done. For the majority of the systems, two exponents are sufficient to provide a good quality fitting, while for one system, three exponents are preferred. Graphical dependence of the fitting quality SD(c)/c\({}_{\rm o}\) on the number of exponential terms of the m-exp. equation fitted to adenosine (single adsorbate and accompanied by silver nanoparticles) adsorption kinetics on activated carbon is drowned in Figure 10. In Table 4, parameters of considered semi-empirical equation are presented: the logarithm of rate constant logk\({}_{\rm i}\); the adsorption half-time t\({}_{0.5\rm i}\) for the respective equation term (\(t_{0.5}=(ln\,2)/k_{i}\)); the numerically calculated the average adsorption halftime t\({}_{0.5}\), and the relative uptake u\({}_{\rm eq}\) (\(u_{eq}=1-\frac{c_{\rm eq}}{c_{0}}\)). Figure 10: Dependence of standard deviations of relative concentration SD(c)/c\({}_{\rm o}\) on the number of exponential terms of the multiexponential equation in fitting experimental adsorption of the adenosine from the one- (**A**) and two-component (**B**) solutions on the activated carbon RIAA.