Synthesis of strontium (Sr) doped hydroxyapatite (HAp) nanorods for enhanced adsorption of Cr (VI) ions from wastewater

The development of high-efficiency adsorbents for heavy metal ion removal from wastewater is highly desirable and challenging due to their synthesis complexity and low adsorption capacities. Herein, we reported the synthesis of strontium (Sr) doped hydroxyapatite (HAp) for the increased Cr (VI) adsorption. The effects of pH, temperature, and time on adsorption performances were studied. As a result, the Sr-HAp nanorods can achieve a Cr (VI) adsorption capacity of 443 mg/g, which is significantly higher than that of HAp nanorods (318 mg/g). To better understand the adsorption mechanism, the Langmuir isotherm model was established. The modeling results indicated that Langmuir monolayer chemical adsorption contributed to the efficient Cr (VI) ion removal for Sr-HAp nanorods adsorbents. The surface area and surface functional groups (O-H) contributed to the different Cr (VI) adsorption capacities between HAp and Sr-HAp.

Automated summary

In this study, a novel strontium-doped hydroxyapatite nanorods were synthesized for enhanced chromium (VI) adsorption, achieving significantly higher adsorption capacity than undoped hydroxyapatite nanorods. The Langmuir isotherm model was used to reveal that monolayer chemical adsorption played a crucial role in efficient chromium (VI) ion removal by strontium-doped hydroxyapatite nanorods, with surface area and surface functional groups contributing to the differences in adsorption capacities between HAp and Sr-HAp.