Use of membrane contactors as an efficient alternative to reduce effluent ecotoxicity

This works reports on the separation and recovery of copper cations from water streams from the wet peroxide oxidation process (WPO) using emulsion pertraction technology (EP) in hollow-fiber contactors as separation technology. The separation of the metal was enhanced by using LIX622N as a selective extractant, and its concentration took place in a sulphuric acid phase. The ecotoxicity characterization, according to the Vibrio fischeri bioassay of the waters coming from the WPO process, revealed that the presence of a residual copper catalyst gave the oxidized waters the character of being ecotoxic. Nevertheless, the subsequent removal of copper in the EP process produced non-ecotoxic oxidized water. Finally, the recovered copper catalyst obtained as concentrated copper sulphate solution in the emulsion pertraction process was recycled to the oxidation reactor, checking experimentally that the oxidation efficiency was maintained.