Organophosphonate-modified hydroxyapatites for Zn(II) and Pb(II) adsorption in relation of their structure and surface properties

The grafting of nitrilotris(methylene)-triphosphonate (NTP) molecules can provide an effective route to modify the surface properties of apatite materials. The higher specific surface area for the modified hydroxyapatite is around 160 m2/g compared to the pure hydroxyapatite (HAp) (120 m2/g). The nitrogen and phosphonate groups are responsible to remove the heavy metals by complextation reactions, suggesting that these low cost sorbents may find applications for the detection of specific metals elements and limited environmental impact.