Electrochemical Treatment of Mixed and Hazardous Wastes

Abstract

Publisher Summary This chapter reveals that electrochemical processes are being developed throughout the world for the ambient temperature destruction of hazardous waste and for the conversion of mixed waste to low-level radioactive waste. The status of the technology is discussed, including measurements of process efficiency and models than can be used for scale-up. Several of these processes are based on Mediated Electrochemical Oxidation (MEO). A mediator, generated by anodic oxidation, is used to destroy organics dissolved in an aqueous phase. The chapter describes the destruction and coulombic efficiencies for MEO process that includes electrolyte, electrode separator, rotating cylinder anode (RCA), measurements of CO 2 evolution, and calibration of analyzer. Knowledge of reaction intermediates and associated mechanisms is needed to thoroughly understand the MEO process. To obtain reaction intermediates for identification by gas chromatography with mass spectrometry (GC/MS), ethylene glycol (EG) and benzene (BZ) were partially oxidized by Ag(II) with a RCA at 40% i L (673 mA and 33°C). Anolyte samples obtained during the partial oxidation of EG were analyzed without extraction. GC/MS was used in an attempt to identify reaction intermediates in samples of anolyte, catholyte, extract, and residual BZ. GC/MS analyses were performed with a Hewlett-Packard 5890/5970 benchtop GC/MS system running on RTE/6.