Layered sodium zirconium arsenate of composition Zr2O3(NaAsO4). 3H(2)O was prepared by the reaction between Zr(OC3H7)(4) and sodium arsenate in alkaline media (pH > 12) under mild hydrothermal conditions (180-200 degrees C). Two hydrogen forms of the zirconium arsenate (psi-ZrAs) Zr2O3(HAsO4). 3H(2)O and Zr2O3(HAsO4). H2O, were prepared by acid treatment of the sodium form. The intercalation of n-alkylamines into the psi-ZrAs from the gas phase was studied. The synthesized materials were characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy and powder X-ray diffraction. The data indicate that the zirconium arsenate is isostructural to psi-Zr2O3)(HPO4). nH(2)O (n = 0.5, 1.5). The new compounds exhibit high hydrolytic stability in alkaline media. The ion exchange behavior of the psi-Zr2O3(HAsO4). 3H(2)O towards alkali, alkaline-earth, and some di- and tri-valent metal cations in different solutions was studied over a wide pH range (2-14) by the batch technique.