Naphthalene Adsorption and Desorption from Aqueous C60 Fullerene

Abstract

The main purpose of this study was to characterize the adsorption and desorption interactions of naphthalene, a model environmental organic pollutant, with C 60 fullerene. C 60 fullerene was used as a model adsorbent for carbonaceous nanoparticles. Typical batch reactors were used to perform adsorption and desorption experiments. Adsorption and desorption of naphthalene to and from C 60 fullerene solids in different aggregation forms was studied, where C 60 was used as purchased, deposited as a thin film, or dispersed in water by magnetic mixing. Adsorption and desorption of naphthalene to activated carbon, a common sorbent, was also studied and compared with that of C 60 . It was found in this study that the enhanced dispersal of C 60 could affect the adsorption of naphthalene by several orders of magnitude. A solid-water distribution coefficient of 10 2.4 mL·g -1 was obtained for adsorption of naphthalene to poorly dispersed C 60, whereas (10 4.2 to 10 4.3 ) ml·g -1 coefficients were obtained for well-dispersed C 60 samples. In addition, desorption of naphthalene from dispersed C 60 samples into aqueous solutions was found to exhibit strong hysteresis. For the desorption over a period of 60 days, only about 11% of total naphthalene was desorbed from C 60 . Possible mechanisms for these observations are discussed.