DC Water Plasma at Atmospheric Pressure for the Treatment of Aqueous Phenol

This study investigated the decomposition of aqueous phenol by direct current (DC) water plasma. The operation of DC water plasma was carried out in the absence of inert gases or air injected and cooling-controlled and pressure-controlled devices. The results indicated that 1 mol.% (52.8 g L -1) phenol was drastically decomposed by DC water plasma touch with energy efficiencies of 1.9 - 108-2.2 - 108 mol J -1. Also, the value of chemical oxygen demand (COD) was reduced from 100-000 mg L-1 down to 320 mg L-1 over a short retention time. The maximum decomposition rate of the COD was 258 mg COD min-1 for the arc power of 0.91 kW. In the effluent analysis, H2 (63-68%), CO (3.6-6.3%), CO2 (25.3-28.1%) were major products in the exhaust gas and CH4, C2H2, HCOOH and C 6H6 in trace level. Further, HCOOH and HCHO were observed in the liquid effluents. Within the current paper, the results indicated that the DC water plasma torch is capable of an alternative green technology for phenol wastewater containing high COD. © 2010 American Chemical Society.