Strontium-doped hydroxyapatite as adsorbent effectively to remove lead ions from water.

In this study, a strontium-doped hydroxyapatite (Sr-HAP) was synthesized by the solgel method, which was used as adsorbent to remove lead ions (Pb) from water. The results showed that the adsorption capacities of the Sr-HAP were obviously higher than those of the HAP, the adsorption capacities of which for Pb reached 651.175 mg/g. The proper increasement in the dosage of adsorbent was beneficial to the removal of Pb by Sr-HAP. Meanwhile Sr-HAP had a wide applicable pH range for Pb. And the increasement in temperature could increase the adsorption capacity of Sr-HAP for Pb to a certain extent. The Langmuir model was used to fit the isotherm adsorption process of Sr-HAP to Pb in water. Compared with HAP, the specific surface area of Sr-HAP has increased by 11.1%, and the pore size distribution of Sr-HAP tended to be smaller and more uniform. Hence, Sr-HAP could be used as an ideal adsorbent to remove Pb in wastewater.