  The electrosorption of Gd$^{3+}$ ions from aqueous 70 mM Gd(NO$_3$)$_3$
solution in monolithic carbon aerogel electrodes was recorded by dynamic
neutron imaging. The aerogels have a bimodal pore size distribution consisting
of macropores and mesopores centered at 115 nm and 15 nm, respectively. After
the uptake of Gd$^{3+}$ ions by the negatively charged surface of the porous
structure, an inhomogeneous magnetic field was applied to the system of
discharging electrodes. This led to a convective flow and confinement of
Gd(NO$_3$)$_3$ solution in the magnetic field gradient. Thus, a way to desalt
and capture paramagnetic ions from an initially homogeneous solution is
established.
