Ozone degradation of 1-naphthol on multiwalled carbon nanotubes/iron oxides and recycling of the adsorbent

Abstract

This work investigated the pre-concentration of 1-naphthol on multiwalled carbon nanotubes (MWCNTs)/iron oxides followed by ozone degradation as a post processing method for degrading 1-naphthol, while recycling the MWCNTs/iron oxides. Ozone degradation kinetics for 1-naphthol on MWCNTs/iron oxides and in solution indicated that the ozone degradation of 1-naphthol was faster on MWCNTs/iron oxides than in solution. The main degradation intermediates were identified by Gas Chromatograph Mass Spectrometer (GC–MS), and the possible pathways of 1-naphthol ozone degradation on the MWCNTs/iron oxides were demonstrated by combining GS–MS with a High Performance Liquid Chromatography. The adsorption capacity of the MWCNTs/iron oxides for heavy metal ions was greatly enhanced after ozone degradation of the adsorbed 1-naphthol, which resulted from the introduction of oxygen-containing groups during the ozone degradation process and was important for recycling adsorbents. Our results indicated that the ozone degradation of 1-naphthol on MWCNTs/iron oxides is a post processing method of adsorption, and this method could degrade the adsorbed 1-naphthol and allow for adsorbent recycling. The pre-concentration of polycyclic aromatic hydrocarbons on MWCNTs/iron oxides prior to ozone degradation is a novel method for industrial wastewater treatment.