The ion-exchange selectivity of divalent transition metal ions on cryptomelane-type manganic acid (CMA) with tunnel structure has been studied using the distribution coefficients (Kd) at a small fractional exchange in nitrate media. All metal ions studied showed linear relationships with a slope of —2 on the log-log plot of Kd vs [HNO3] which clearly indicated that the adsorption process is an “ideal” ion-exchange. The selectivity increased in the following order: Pb ↣ Mn > Co > Cu > Hg > Cd > Zn > Ni. The high selectivity of the manganic acid was successfully utilized in the removal of CO2+ from seawater and tap water.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering