Abstract
The present paper describes he synthesis of hydroxyapatite‑sodium alginate (CaHAp-Alg) hybrid materials using a co-precipitation method with different content of the bio-polymer (0, 5, 10 and 20%). Prepared materials were characterized using X-ray diffraction, Infrared spectroscopy, scanning electron microscopy, Energy Dispersive X-Ray Analysis, thermal analysis and specific surface area. The X-ray powder analysis showed that the crystallinity is affected by the presence of alginate. The BET N2 adsorption showed evidence changes in textural properties of materials after chemical modification. The adsorption capacities of Methylene Blue (MB) were investigated with respect to the effect of adsorbent amount, pH value, ionic strength, contact time, adsorbent dose, temperature and initial dye concentration. The pseudo-second-order and Langmuir isotherm equations were found to describe the adsorption mechanism. The maximum adsorption capacity of CaHAp and CaHAp-(Alg)10 were equal to 77.510 and 142.850mg·g−1, respectively. The high registered capacities of MB removal suggest the potential use of these materials in the treatment of contaminated waters.
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•Hydroxyapatite-sodium alginate hybrids were prepared for the removal of Methylene Blue.•Dye adsorption capacity of CaHAp-(Alg) was extremely influenced by experimental conditions.•Highest sorption capacity was achieved using CaHAp-(Alg)10.•The maximum adsorption capacity was found to be 142.85mg·g−1 at 25°C.