Abstract
The transport of gold ions (5×10-5M) from a diluted hydrochloric acid solution to a stripping solution across a supported liquid membrane (SLM) containing 0.1M solution of polydentate neutral sulfide podand 1, 12-di-2-thienyl-2, 5, 8, 11- tetrathiadodecane (TTD) in m-chlorotoluene was studied. The rate of transport of gold ions increased in the sequence of the stripping solutions, NaBr_??_NH3, thiourea<NaSCN<NaI<thiosulfate. Among three microporous polymers used, the rate with Celgard 2500 membrane is ca. 23% higher than for Celgard 4510 or 2502. The present result shows that the selectivity for gold ion is good against copper, zinc and iron ions present in 200:1 excess. The gold flux (J) increases almost linearly with an increase in the initial gold concentration over the range 10-5-10-4M; for 5×10-5M Au it is equal to 10.3×10-8mol cm-2 h-1.
