The sorption of Pb(II) from aqueous solution using NKF-5 zeolite was investigated by batch technique under ambient conditions.
The NKF-5 zeolite sample was characterized by using FTIR and X-ray powder diffraction in detail. The sorption of Pb(II) was
investigated as a function of pH, ionic strength, foreign ions, and humic substances. The results indicated that the sorption
of Pb(II) on NKF-5 zeolite was strongly dependent on pH. The sorption was dependent on ionic strength at low pH, but independent
of ionic strength at high pH. At low pH, the sorption of Pb(II) was dominated by outer-sphere surface complexation and ion
exchange with H+ on NKF-5 zeolite surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH. From the
experimental results, one can conclude that NKF-5 zeolite has good potentialities for cost-effective preconcentration of Pb(II)
from large volumes of aqueous solutions.