Study of the Process and Mechanism of the Remediation of Phenol Contaminated Soil by Plasma Vibrated Bed

Soil pollution is an important problem. The organic components of soil pollution are complex, and pose a significant threat to human health. In this work, a low-temperature plasma vibrated bed is applied to remediation of soil polluted by organics, with attention focused on phenol as a model pollutant. In the experiment, many factors of phenol degradation are studied and determined, such as discharge voltage, carrier gas, and soil moisture content. Increasing vibration frequency, decreasing electrode spacing, increasing voltage and a weakly alkaline soil are conducive to the degradation of pollutants. Air and oxygen give better degradation than nitrogen. The active particles generated in the discharge, such as ·OH, H2O2 and O3, are shown to play an important role in degradation of phenol. In addition, maleic acid and oxalic acid are found as intermediate product during the process of phenol degradation. Furthermore, according to the qualitative and quantitative analysis of phenol degradation products, the degradation mechanism diagram of phenol in soil is drawn up, which is instructive to improve the performance of the plasma vibrated bed in the future research.