Removal of VOCs from wood by introducing activators to form hydroxyl radicals in-situ generation platform

Abstract

Wood contains abundant extractives and volatile oils, resulting in the emission of hazardous volatile organic compounds (VOCs) and unpleasant odors. The homogeneous Fe2+ catalyzed Fenton reaction remains an attractive advanced oxidation process (AOPs) for the degradation of hazardous organic contaminants, but limited by due to the poor permeability of wood and wide distribution of extractives, the effective removal of wood extractives remained a challenge. Herein, a facile approach toward forming an in-situ ·OH radical generation platform was proposed by introducing EDTA-Fe2+ chelating agent into parenchyma cells and resin canals of wood by vacuum impregnation. Oxidation process was carried out using a “respiratory impregnation” method that imitated human respiration. The Electron paramagnetic resonance (EPR) analysis reveals that·OH was generated in-situ as the primary reactive species. Various controlling factors, including Fe2+ concentration, pH value, and H2O2 concentration were evaluated. The removal rate of VOCs was estimated by headspace solid-phase micro-extraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS). The best results (89.5% removal without cycling treatment) were observed at pH = 3, H2O2 = 20 mM and Fe2+ = 200 mM. This work improves the feasibility of using the Fenton system to remove VOCs from wood products.