New nanocomposite adsorbent basedlon silica and iron(III) oxide, thermally treated at 200degreesC has been used for the arsenic(V) removal. Adsorbents were prepared by sol-gel method, the iron oxides being generated in situ during the sol-gel process. Nanocomposite materials thus obtained have a convenient porosity and nanosized iron oxide content. The sorption experiments have been carried out in a batch mode by using aqueous solutions containing 1000 ppm As. The influence of different experimental parameters on the adsorption capacity was investigated. The effect of magnetic field on the enhancement of adsorption process was also revealed.