Adsorption Behavior of Magnetic Multiwalled Carbon Nanotubes for the Simultaneous Adsorption of Furazolidone and Cu(II) from Aqueous Solutions

A magnetic multiwalled carbon nanotubes (MWCNTs) nanocomposite was synthesized and was used as an adsorbent for removal of furazolidone (FZD) and Cu(II) from aqueous solutions. Influence of parameters on the adsorption capacity, including initial pH, contact time, and temperature, were investigated. Langmuir and Freundlich adsorption models were used for the mathematical description of adsorption equilibrium. Experimental data were analyzed by pseudo first order, pseudo second, and intraparticle diffusion order kinetic models. Thermodynamic parameters such as ΔH0, ΔS0, and ΔG0 calculated from adsorption process revealed that the adsorption process was spontaneous, exothermic, and a physical process in the experimental temperature range. Cu(II) had a strong suppression effect on FZD binding in the simultaneous adsorption and FZD preloading experiment. As for Cu(II) simultaneous adsorption and preloading, the impact of FZD on Cu(II) desorption was almost negligible. The practical application of magnetic MWCNTs and regeneration of magnetic MWCNTs for several cycles using hydrochloric acid and N,N-dimethylformamide were also investigated. Results of the study showed that the carbon nanotubes have good regeneration property and can be used as potential adsorbent for FZD and Cu(II) in water/wastewater.