Separation of trace palladium chloro complexes from wastewater of electroless plating process via hollow fiber supported liquid membrane

Abstract

The separation of palladium (Pd (II)) from wastewater containing copper (Cu (II)) and nickel (Ni (II)) is investigated via hollow fiber supported liquid membrane (HFSLM). The viability to separate Pd (II) was established by controlling the influence of operating conditions viz. aqueous feed acidity, carrier concentration, types of stripping solution as well as flows rate of feed and stripping solutions. A complete separation of Pd (II) acheiving >99% extraction and 87.09% recovery was demonstrated under optimum conditions of 6%(v/v) Aliquat 336, pH 2 as aqueous feed acidity, 0.5 M thiourea mixed with 0.1 M HCl as a strippant and 100 mL/min flow rate for both feed and stripping solutions. Transportation of Pd (II) across HFSLM was also investigated. The mass transfer in the LMs was found to be the rate controlling step. An analysis of mass is presented to study the transport phenomena of Pd (II) across HFSLM. Results indicate that the model proves to be an effective approach for predicting the transportation of Pd (II) across the system. It is significant that the model predictions were found to be in good agreement with the obtained experimental data.