Desalination, Vol.180, No.1-3, 139-150, 2005
Cyanide ions transport from aqueous solutions by using quaternary ammonium salts through bulk liquid membranes
Extraction experiments were carried out to determine the suitable solvent and carrier type. Five different solvents and carriers were used and verified. Trichloromethane and tetraoctyl ammonium chlorides were found to be the most appropriate solvent and carrier type for this study. The coupled transport of cyanide ions in aqueous solutions through bulk liquid membrane (BLM) was investigated using various stirring speeds and temperatures. Cyanide ion transport through BLM technique was analyzed according to coupled non-steady state kinetics of two consecutive irreversible first order reactions. The influences of the kinetic parameters (k(1d), k(2m), k(2a), R-m(max), t(max), J(d)(max), J(a)(max)) for the various stirring speeds in the system were established. The removal and recovery efficiencies of the cyanide ions transported from aqueous solutions in 360 min were 99.4 and 82%, respectively. As the stirring speed was increased, both the efficiency of transport and recovery of cyanide ions from aqueous solutions were increased. On the other hand, for maximum membrane entrance (J(d)(max)) and exit (J(a)(max)) fluxes the activation energies were calculated as 21.6 kcal/mol and 10.5 kcal/mol, respectively.
Keywords:cyanide ion;bulk liquid membrane;coupled transport kinetics;quaternary ammonium salts;stirring speed;temperature