Abstract
Carboxylate group functionalized multi-walled carbon nanotubes (MWCNT–COOH) were synthesized by microwave-assisted method and characterized by Infrared spectroscopy; XRD methods and scanning electron microscope (SEM). These were used as adsorbent for the rapid removal of hazardous toxic dye Malachite green (MG) from aqueous phase. The impact of several effective parameters such as contact time, temperature, initial concentration, and agitation speed was investigated and the optimized values of influential parameters like pH, contact time, temperature, initial concentration, and agitation speed on experimentation were found to be 6, 50min, 298K, 15mg/L and 150rpm respectively. The experimental kinetic data were well fitted to the pseudo-first order reaction kinetics and results. Different adsorption isotherm models like Freundlich, Langmuir and Temkin are used to describe equilibrium adsorption in the adsorbent system and on experimentation the best agreement was achieved with the Langmuir model, for MG, the adsorption capacity of MWCNT–COOH surface was 49.45mg/g at 298K.
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•MWCNT–COOH were synthesized by microwave-assisted and characterized by several analytical techniques.•Functionalization of CNTs leads to increase in the adsorption capacity of adsorbent•functionalization typically involves oxidation using acids or oxidants.