Study of the thermodynamic properties of the adsorption of the non-steroidal anti-inflammatory drug naproxen on prepared activated carbon

In this study, a new adsorbent material (chemically treated activated carbon) was prepared from an environmentally friendly, inexpensive and available plant source, namely pine tree cones. Naproxen was chosen as a model drug to study the performance of the adsorption process. Thermodynamic functions were calculated for the adsorption of the drug naproxen on the surface of the prepared chemically treated activated carbon. The analytical method was used to achieve the standard calibration curve for the drug naproxen in order to calculate the amount of the drug adsorbed and the remaining in the solution, following the Beer-Lambert law, and using the spectroscopic method to measure the optical spectrum in the ultraviolet region. Then calculate the thermodynamic functions for the adsorption process (H, G, S) within an experimental range of temperatures ranging from (338 - 288 K). The results of the thermodynamic study showed that the adsorption of naproxen is a heat-emitting process through the values of (H ) is negative with the fixed concentration and at the range of temperatures used, where the values of (G) are negative and indicate that the adsorption process is spontaneous in nature and increases spontaneously with an increase in temperature with the concentration and adsorbent being constant. This indicates that physical adsorption is dominant and that the values of (S) are Negative, meaning it is less regular in the stages of the adsorption process compared to its equilibrium state, and it has a high degree of freedom on the surface of the adsorbent.