Studies on adsorption of m-nitrophenol on hydroxyapatite nanopowders

Hydroxyapatite (HAp) nanopowders were prepared by chemical precipitation method, and the powders were characterized by FETEM, XRD and ICP-AES technologies. The adsorption results of m-nitrophenol on HAp nanopowders in aqueous showed that the adsorption capacity increased with the increase of the phenol concentration and the temperatures. The adsorption process was in accorded with Freundlich and Langmuir equations. The adsorption behavior was proved to be a spontaneous, endothermic and physical process with increasing entropy.