Adsorption of sulfacetamide on commercial activated carbons: statistics and kinetics of adsorption

The present study analysed the adsorption of sulfacetamide on six commercial activated carbons. Adsorption on all analyzed sorbents was favourable the tested activated carbons are characterized by average adsorption properties compared to a chemotherapeutic agent (monolayer capacity q(m) ranging from 34.58 to 55.54 mg/g). Analysis of the Pearson correlation coefficient revealed a mod-erate correlation between monolayer capacity and specific surface area, and a very high correlation between monolayer capacity and total pore volume or micropore volume. The specific surface area and pore volume are important but not the only features of activated carbons, determining adsorp-tion capacity of sulfacetamide. Based on the analysis of various models of adsorption kinetics and their matching to the test results, they can be ranked in the following order (taking into account the correlation coefficient R-2): Elovich > intraparticle diffusion > pseudo-first-order > pseudo -second-order. For studies of adsorption statics, the models used in this paper are characterized by a high accuracy of results. Based on the correlation coefficient, they can be ranked as follows: Temkin > Toth > Langmuir > Freundlich > Redlich-Peterson > Jovanovica approximate to Halsey. The effect of pH and solution temperature on the amount of adsorption and that of carbon dose on adsorption efficiency were analyzed. It was found that the highest adsorption was obtained for the solution at pH = 3 (unionised sulfacetamide) and the lowest at pH = 9, in which sulfacetamide is present as an anion. Moreover, it was found that the higher the temperature, the lower the adsorption.