Zeolite Y, erionite, and bentonite have been used in this work to remove Np-239 and U-235 fission products from aqueous solutions at various pH values. it was found that the sorption of fission products by aluminosilicates takes place by different mechanisms, mainly ion exchange, precipitation, and electrostatic surface interaction. The radionuclides content was determined by gamma-spectrometry, and x-ray diffraction was used to learn whether the solids maintained their crystallinity at different pH values.