the particles. A container with a laboratory disperser is included to prevent particle
aggregation. Moreover, inert gas is supplied throughout the experiment above the level
of the suspension. The device is further equipped with a pressure detector at the inlet to
the column, which provides additional information about the ongoing processes.
It is possible to measure the concentration at the coordinates outside the base of
the column to obtain accurate information about the boundary conditions.
Example migration curves of commercial nZVI particles NANOFER 25 (NANO
IRON s.r.o., Czech Republic) measured over a 10-minute interval are shown in
Fig. 30.2. The nZVI concentration was 10 g/L, the column load was quartz sand with
a grain of 1.2 mm. The dosing rate corresponds to a leakage rate of 100 m/24 h.
Selected values can also be shown in the defined column positions (Fig. 30.3).
30.3 Cascade Column as an Advanced Alternative
for Mobility Experiments
When nZVI particles are injected into a homogeneous isotropic environment, the
treated area gradually forms an expanding cylindrical zone around the application
well. The area at the bottom of the well is spherical. Therefore, the nZVI mobility
Fig. 30.2 Migration curves
of NANOFER 25 repeatedly
measured every 10 min
Fig. 30.3 Values measured
by detector at position
130 mm during whole
experiment with
NANOFER 25