Treatment of Organic Wastewater by Supercritical Water Oxidation

Abstract

Supercritical water oxidation (SCWO) is a robust process in removing the hazardous organic wastes. Therefore, it is necessary to improve the SCWO process to eliminate the organic hazardous wastes. In present work, SCWO process used cyclohexylamine (CHA) as the organic chemical model. The co-oxidizers consisted of propylene glycol (PG), methanol and the oxygen source was hydrogen peroxide. The experiments were conducted using at a laboratory scale. A plug-flow reactor was utilized at different operating temperatures ranging from 425 to 525 ºC, the critical pressure was 25 MPa. At working temperatures, the co-oxidizer and the oxidant ratios were also investigated . The results indicated that the temperature had an impact on the removal efficiency of cyclohexylamine. The maximum total organic carbon removal (TOC) in the presence of propylene glycol was achieved with 98% at 525 ºC and the residence time was 14 s.