| 초록 |
EDTA (ethylendiaminetetraacetic acid) is a representative reagent used in chemical cleaning processes. Chemical cleaning processes result in the generation of wastewater consisting of EDTA-metal complexes that are resistant to biodegradation. In this work, a two-staged supercritical water gasification (SCWG) process was developed for the destruction of EDTA-Fe metal complex wastewater. In the first stage of the SCWG process, EDTA-Fe complex wastewater was treated in supercritical water at 420-500oC, 28MPa, and 60h-1 LHSV to separate Fe metal from EDTA reagent. More than 99.9% of Fe metal was separated and precipitated from the reagent in supercritical water at 450oC but the gasification of EDTA was less than 40% in terms of COD and TOC destructions. The liquid products containing Fe-free EDTA reagent and its decomposed organic compounds were delivered to a tubular flow reactor packed with activated charcoal or Ni-Y/AC catalyst at 480-560oC and 28MPa. Destruction of organic compounds to gaseous product was 97.3% for activated charcoal and 99.5% for Ni-Y/activated charcoal catalyst. |
