Adsorption of selected pharmaceuticals on activated carbons from water

Abstract

The possibility of using activated carbon for the removal of salicylic acid andiibuprofen sodium has been explored. These compounds are observed in crude and treated sewage and in surface water. The effect of pH on the adsorption efficiency was assessed. Tests were carried out from solutions with pH ranging from 2 to 10 (salicylic acid) and from 6 to 10 (iibuprofen sodium). It was found that the higher pH, the lower the adsorption of the compounds tested. Salicylic acid was most efficiently adsorbed from a solution with pH = 2, in which it occurred mainly in an undissociated form. The achieved efficiency of salicylic acid adsorption from solutions with pH=2 was 91%, while from those with pH=10, it was 55% (Co=4 mmol/L). The efficiency of removing ibuprofen sodium from the pH=6 solution was 64%, while from the pH = 10 solution, 60%.The adsorption of both salicylic acid and ibuprofen sodium follows the kinetics equation of the pseudo-2nd order. For the description of the adsorption isotherms, the Freundlich, Langmuir, Temkin and Dubibin-Radushkevich models were employed. The both compounds are described with the highest correlation coefficient in the case of the Freundlich equation.