Naphthalene adsorption and desorption from Aqueous C60 fullerene

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.