An efficient method for removal of pentachlorophenol using adsorption and microwave regeneration with different magnetic carbon nanotubes

Abstract

Various magnetic carbon nanotubes (CNTs) Co_0.5M_0.5Fe₂O₄-CNTs (M = Cu, Mn, Ni, Zn) were successfully prepared and applied for treatment of pentachlorophenol (PCP) with adsorption and microwave irradiation process. The Co_0.5M_0.5Fe₂O₄-CNTs were characterized by transmission electron microscopy, X-ray diffraction, vibrating sample magnetometry, and microwave absorption spectroscopy. The adsorption experiment results showed the adsorption capacity for PCP was in the following order: Co_0.5Cu_0.5Fe₂O₄-CNTs > Co_0.5Mn_0.5Fe₂O₄-CNTs > Co_0.5Ni_0.5Fe₂O₄-CNTs > Co_0.5Zn_0.5Fe₂O₄-CNTs. After adsorption, the Co_0.5M_0.5Fe₂O₄-CNTs was separated by magnetic field and regenerated by microwave irradiation at 850 W for 180 s. It was confirmed that after six adsorption and microwave regeneration cycles, the regeneration efficiency maintained over 90%. In particular, Co_0.5Cu_0.5Fe₂O₄-CNTs exhibited excellent adsorption capacity and reusability. These results can open a new avenue for treatment of chlorinated organic compounds with efficiently and non-secondary pollution.