Initial concentrations of adsorbate influence on synergistic effect between a magnetic field and graphene oxide-carbon nanotube composite for Pb2+ and phenol adsorption

Abstract

The effects of initial concentrations of adsorbate on scale inhibition of circulating water and adsorption properties for Pb2+ and phenol were studied under the synergistic effect of the magnetic field and the adsorbent. The sulphydryl and amino-modified graphene oxide/oxidized multiwalled carbon nanotubes (NH2-SH-GO/o-MWCNTs) were prepared and used as the adsorbent. The results showed that, as the initial concentration of adsorbate increased, the molecular activation energy of the circulating water also increased, while the intramolecular energy changed slightly. Meanwhile, the relative variation in the proportion of free water increased and the equilibrium adsorption capacities for Pb2+ and phenol also increased. The adsorption process of NH2-SH-GO/o-MWCNTs for Pb2+ and phenol under the synergistic effect of the magnetic field and the adsorbent conformed to the pseudo-second-order kinetics and Freundlich isotherm model. The aforementioned results reveal that the combined application of the magnetic field and the adsorbent can not only inhibit scale formation but also can promote the adsorption for Pb2+, which showing potential for practical application.