Enhanced degradation and mineralization of 4-chloro-3-methyl phenol by Zn-CNTs/O₃ system

A novel zinc-carbon nanotubes (Zn-CNTs) composite was prepared, characterized and used in O₃ system for the enhanced degradation and mineralization of chlorinated phenol. The Zn-CNTs was characterized by SEM, BET and XRD, and the degradation of 4-chloro-3-methyl phenol (CMP) in aqueous solution was investigated using Zn-CNTs/O₃ system. The experimental results showed that the rate constant of total organic carbon (TOC) removal was 0.29 min^-1, much higher than that of only O₃ system (0.059 min^-1) because Zn-CNTs/O₂ system could generate H₂O₂ in situ, the concentration of H₂O₂ could reach 156.14 mg/L within 60 min at pH 6.0. The high mineralization ratio of CMP by Zn-CNTs/O₃ occurred at wide pH range (3.0-9.0). The increase of Zn-CNTs dosage or gas flow rate contributed to the enhancement of CMP mineralization. The intermediates of CMP degradation were identified and the possible degradation pathway was tentatively proposed.