VOC degradation by microwave-induced metal discharge and thermal destruction: a comparative study

Abstract

The effective treatment of volatile organic compounds (VOCs) is essential because of their direct effects on air pollution and human health. This paper introduces microwave-induced metal discharge as a highly effective and byproduct value-added approach to degrade high-concentration toluene as a model VOC. The effect of the factors that influence the discharge intensity, including the metal type (Fe, Cu, Ni, Zn) and amount, was investigated. Degradation efficiency of toluene can reach 79.76% under optimal discharge condition. In addition, the discharge method was compared with traditional thermal destruction at 700 °C, 900 °C and 1100 °C. The gaseous and liquid cracking products of toluene produced by the microwave-induced metal discharge method were almost similar to those obtained under thermal destruction at 900 °C; however, the solid-phase discharge products were nanoparticles that demonstrated good graphitization, while the thermal destruction products were amorphous microparticles. This work offers an effective and flexible way to degrade high-concentration VOCs and also provides an application reference for biomass tar cracking and removal of other organic pollutants.