Kinetics of diclofenac adsorption from aqueous solution on commercial activated carbon
This paper studies the possibility of using activated carbon as an adsorbent
for diclofenac (DFC) from aqueous medium. Batch sorption experiments were
performed, and the influence of different parameters was studied: adsorbent
dose, contact time and temperature. The experimentally obtained results were
fitted according to two linear theoretical models of isotherms: Freundlich and
Langmuir and according to two different kinetic models: pseudo-first and
pseudo-second order. The optimal adsorption parameters were found to be:
dose of adsorbent 0,5 g; contact time 60 minutes and temperature 20ºC, and
the removal efficiency of diclofenac at these parameters was 92.8%.The results
showed that the adsorption process follows a pseudo-second order kinetics and
better matches the Freundlich isotherm model. The values of thermodynamic
parameters indicate that adsorption process is spontaneous and exothermic.
Based on the obtained data, it can be concluded that commercial activated
carbon is an effective adsorbent for diclofenac from aqueous solution.