Lead accumulation on montmorillonite

摘要

The structure of lead and calcium-lead montmorillonites was studied by IR spectroscopy and scanning electron microscopy. The IR spectra showed no structural changes of the montmorillonite crystal lattice during calcium-lead cation exchange, only the intensities of hydrate water of the interlayer cation vary and the OH band on the edges disappears. Scanning electron microscopic studies showed that the distribution of lead is fairly even on the major part of the surface; however, there are places where the concentration of lead is higher than the mean surface concentration. The diameter of them is less than 1 um. Similar lead enrichments were found on a natural clay sediment of a lake in Hungary. Lead ions adsorb on montmorillonite by cation exchange in the interlayer space and a heterogeneous nucleation on the particle surface followed by crystal growth.