Using physicochemical methods we showed that continuous (15 days) exposure of monazite powder in humic acid (HA) solutions
with different acidity gives rise to one to two orders of magnitude growth in the concentration of the monazite’ p-, d- and
f-elements of Periodic Table (Mg, Al, Si, P, Pb, Ti, Bi, Sc, Ti-Zn, REE, Th, U). The growth in the elements concentration
in the humic solutions contacting monazite is shown to depend on the initial concentration of HA in the solutions, pH. It
is concluded that these factors should be taken into consideration when inorganic phosphates and alike phases are used as
a matrix for the radionuclide wastes solidification.