Recovery of phenol with CYANEX((R)) 923 in membrane extraction-stripping systems

The recovery of phenol from aqueous solutions with CYANEX (R) 923 was studi ed. Classical dispersive extraction and three membrane extraction-stripping systems (bulk liquid membranes, three-phase hollow fiber contactor and two hollow fiber modules set-up) were used. It was found that CYANEX (R) 923 w as a convenient carrier for recovery of phenol from aqueous streams in extr action-stripping membrane processes. The problem of emulsion formation, so important in dispersive extraction, was avoided. Both mass transfer experim ents in different membrane systems and measurement of the dynamic interfaci al tension demonstrated importance of the interfacial phenomena occurring i n the stripping stage. A blocking of this interface was observed that resul ted in a decrease of phenol mass transfer.