<p><span style="font-size:14px"><span style="font-family:Arial,Helvetica,sans-serif">Arsenic(As) containedin drinking water can cause adverse effect son human health. This study investigated the effect of hydroxyapatite nano particles (nano-HAp) on sorption of As(V) ions in aqueous solution. The amounts of arsenic ion,nano-HAp and pH on removal efficiency were also investigated.Resultsshowed that theremoval ofarsenatefromwater using hydroxyapatite nanoparticles, improved with increasing pH. The optimum amount of nano-HAp for As (V) removal isfound to be 0/6g/L with the removal efficiency of 88 %. The sorption data were then correlated with the Langmuir, Freundlich, adsorption isotherm models. The results indicated that nano-HAp can be used as an effective adsorbent for removal of As(V) from aqueous solution.</span></span></p>