The membrane was cut into rectangular pieces of 8x6 cm and was soaked in the premeasured concentration of TDDA diluted with xylene in Petri dish for overnight.
If tri-n-dodecylamine (TDDA) is represented by L, the following possibilities of reactions may take place.
Likewise by drawing log J[eta] versus log [L] and maintaining [[Cl.sup.-]], [[H.sup.+]], and [C.sub.f] constant, the slope of the plot will give a number of moles (n) of TDDA contributing in complex formation of Zn (II).
The slope of the plot is 2.008, and this indicates that two molecules of TDDA take part in the complex formation.
The effect of HCl concentration on extraction Zn (II) was observed by varying the concentration of HCl in the range of 0.5 mol/[dm.sup.3] to 3.0 mol/[dm.sup.3], while keeping the concentration of TDDA in the liquid membrane phase at 0.80 mol/[dm.sup.3] and concentration of NaOH on strip side at 2.0 mol/[dm.sup.3].
As the transport study concluded that two molecules of TDDA and H[.bar]+ are involved in the complex formation of Zn (II), the complex formed during this extraction study may be [(LH).sub.n] x Zn([Cl.sub.2] + n).
To investigate the effect of NaOH on the transport of Zn (II), numerous concentrations of NaOH in the range of 0.05 mol/[dm.sup.3] to 2.5 mol/[dm.sup.3] were used, while keeping the TDDA concentration at 0.80 mol/[dm.sup.3] and HCl concentration in feed solution at 2.0 mol/[dm.sup.3].
The polypropylene as supported liquid membrane, TDDA as a carrier, was utilized for extraction of Zn (II) from waste discharge liquor of galvanizing plant.