Removal of dye pollutants using multi-walled carbon nanotubes with magnetic characteristics

Abstract

Carbon nanoparticles (CNPs) which are multi-walled carbon nanotubes (MWCNTs) and multi-shell carbon nanocapsules (CNCs) could be synthesized by co-pyrolysis of ferrocene/glycerol mixture. They are utilized for removal of synthetic dyes dispersed in aqueous solutions. The synthesized CNPs which containing Fe-nanoparticles could be collected from the suspension by applying external magnetic field. In this research the effects of contact time, initial dye concentration, CNPs adsorbent dosage and initial pH value of dye solutions on dye adsorption performance are comprehensively investigated. The maximum adsorption capacities are 22.11, 34.26 and 84.94 mg/g for Methylene Blue, Reactive Red31 and Reactive Black5, respectively. Adsorption kinetic and adsorption isotherm were examined to get confirmation of the pseudo second-order model and Freundlich adsorption characteristics, respectively. The synthesized CNPs exhibit main advantages of its simplicity in regeneration with typical acid and recovery by magnetic field. After 3-cycle of adsorption and regeneration, final adsorption capacity of Methylene Blue, Reactive Red31 and Reactive Black5 on the synthesized CNPs is 20.7, 19.8 and 60.0 mg/g, respectively.