الخلاصة:
Abstract
A range of synthetic dyes released by industrial activities pose a threat to the protection of the environment. In this study the removal of bromophenol blue dyes (BPB), a form of synthetic dye, was successfully performed on graphene oxide nanosheets. The graphite oxide GO-450 nm was prepared by oxidation-reduction reaction (Hummers method). A tip sonicator was used to reduce the size particles to 200 nm under controlled conditions (time and power of sonication). The structure of these two sizes ofGO was confirmed by scanning electron microscopy (SEM) and by statistical analysis. The oxygenated functional groups on the surface of both sizes of GO nanosheets were characterized by FTIR spectroscopy.The effect of several factors such as pH, adsorbent dose, contact time, initial dye concentration and temperature on the adsorption of BPB dye on GO particles was investigated. The adsorption isothermal data showed better fitting with Langmuir isotherm model than the Freundlich model. The adsorption capacities were found to be 28.57 mg/g and 40 mg/g for GO-450 nm and GO-200 nm after 40 minutes of contact time, respectively. The kinetic data for adsorption process obeyed a pseudo-second-order rate equation. The thermodynamic parameters such as ΔG, ΔH and ΔS were also determined,the obtained values indicated that the adsorption process was spontaneous and exothermic in nature.
