Determination of dispersity of crushed granite

Summary Experimental crushed granite column breakthrough curves, using ⁹⁹Tc as spike tracer and ³H as invariant tracer, were analyzed by different linear regression techniques. Dispersity of crushed granite and the retardation factor of ⁹⁹TcO₄^- on the crushed granite were determined simultaneously by one linear regression. Dispersity of crushed granite was also obtained with ³H as invariant tracer by the other linear regression. The dispersities found by spike source and invariant source methods are compared. Experimental results show that the dispersity found by the spike source method is close to that found by the invariant source method. This indicates that dispersity is only a characteristic of the dispersion medium.