Recovery of heavy metal ion from slurry adsorbent by packed column of ion exchange membrane.

Abstract

The recovery of heavy metal ions adsorbed on slurry was examined by using a column packed spirally with an ion exchange membrane. The slurry solution containing partly eluted heavy metal ions was continuously fed into the column. Theoretical treatments for rate of mass transfer and equilibrium were carried out by a numerical calculation. The calculated results showed good agreement with the experimental results. It was assumed that the value of liquid-film mass transfer coefficient for the ion exchange membrane in the slurry solution is 0.37 time as large as that in the slurry free aqueous solution. Two equilibrium relationships for the heavy metal ion enabled us to estimate the optimal concentration of eluting agent. With respect to the equilibrium relationships, the first is between aqueous solution and slurry adsorbent and the second is between aqueous solution and spirally packed ion exchange membrane. The desorption of ions from the membrane was discussed experimentally and theoretically.