Continuous electro-scrubbers for the removal of perchloroethylene: Keys for selection

Abstract

• PCE removed continuously using packed column and jet-mixer electro-scrubbers. • Important chemical reactivity of PCE. • No significant improvement with the addition of cobalt mediators. • Better performance of jet-mixers electro-scrubbers. In this work, the removal of perchloroethylene (PCE) using continuous-operation electro-scrubbers is evaluated. Two types of electro-scrubbers were made by combining a jet mixer or a packed absorption column with a single flow-cell. The absorbent/electrolyte is recirculated between both devices, being electrolyzed in the cell and retaining the pollutant in the scrubber. In both scrubber’s system, an important amount of PCE was absorbed into the electrolyte and the application of electric current significantly improved the results, highlighting the efficiency of the integration of technologies. Tests in the absence of absorbent/electrolyte confirmed the reactivity of the PCE in the wet gas phase. The jet-mixer system turned out to be more efficient than the packed column, yielding better results both in absorption and electro-absorption modes, and reaching a PCE removal greater than 90%. Meanwhile, the addition of cobalt mediators did not improve the electro-scrubbing efficiency as initially expected: in the case of the packed column electro-scrubber there were no changes while in the case of the jet mixer surprisingly it is generated a negative effect.