Removal of methyl violet by adsorption onto activated carbon derived from coffee residues

The study aimed to investigate the adsorption efficiency of methyl violet (MV) dye on activated carbon (AC) derived from coffee residues. A batch adsorption study was performed to examine various contributory parameters including contact time, solution pH, adsorbent dose and initial dye concentration. The morphology of the AC was studied by means of scanning electron microscopy (SEM). The results showed that maximum adsorption of MV dye on activated carbon occurred with a contact time of 60 min, solution pH of 9.0 and adsorbent dose of 0.3 g. The equilibrium adsorption data were analysed using Freundlich and Temkin isotherms. The adsorption isotherm was found to follow the Freundlich isotherm. Adsorption behavior of MV dye follows mechanism of physical adsorption which is occurred by heterogeneous surface. The results indicate that the AC from coffee residues is a suitable adsorbent for the adsorption of dyes.