Hydroxyapatite Nanopowders for Effective Removal of Strontium Ions from Aqueous Solutions

Silviu Adrian Predoi; Steluta Carmen Ciobanu; Mariana Carmen Chifiriuc; Mikael Motelica-Heino; Daniela Predoi; Simona Liliana Iconaru

doi:10.3390/ma16010229

Hydroxyapatite Nanopowders for Effective Removal of Strontium Ions from Aqueous Solutions

Materials (Basel). 2022 Dec 27;16(1):229. doi: 10.3390/ma16010229.

Authors

Silviu Adrian Predoi^{1

2

3}, Steluta Carmen Ciobanu⁴, Mariana Carmen Chifiriuc^{3

5

6}, Mikael Motelica-Heino⁷, Daniela Predoi⁴, Simona Liliana Iconaru⁴

Affiliations

¹ Département de Physique, École Normale Supérieure Paris-Saclay, 4 Avenue des Sciences, 91190 Gif-sur-Yvette, France.
² Physique Fondamentale, Université Paris-Saclay, 3 Rue Joliot Curie, 91190 Gif-sur-Yvette, France.
³ Life, Environmental and Earth Sciences Division, Research Institute of the University of Bucharest (ICUB), University of Bucharest, 060023 Bucharest, Romania.
⁴ National Institute of Materials Physics, Atomistilor Street, 077125 Magurele, Romania.
⁵ Department of Microbiology, Faculty of Biology, University of Bucharest, 1-3 Aleea Portocalelor Str., District 5, 060101 Bucharest, Romania.
⁶ Biological Sciences Division, The Romanian Academy, 25, Calea Victoriei, 010071 Bucharest, Romania.
⁷ Department of Civil Engineering and Environment, Université d'Orléans, ISTO, UMR 7327 CNRS, 1A Rue de la Férollerie, 45071 Orléans, France.

Abstract

Drinking water contamination has become a worldwide problem due to the highly negative effects that pollutants can have on human organisms and the environment. Hydroxyapatite (HAp) has the appropriate properties for the immobilization of various pollutants, being considered amongst the most cost-effective materials for water decontamination. The main objective of this study was to use synthesized hydroxyapatite for the elimination of Sr²⁺ ions from contaminated solutions. The hydroxyapatite used in the decontamination process was synthesized in the laboratory using an adapted method. The hydroxyapatite powder (HAp) resulting from the synthesis was analyzed both before and after the elimination of Sr²⁺ ions from contaminated solutions. The efficiency of the HAp nanoparticles in removing Sr²⁺ ions from contaminated solution was determined by batch adsorption experiments. X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to study the HAp samples before and after the removal of Sr²⁺ ions. The ability of HAp nanoparticles to eliminate strontium ions from contaminated solutions was established. Moreover, the removal of Sr²⁺ ions from the contaminated aqueous solutions was highlighted by ultrasound measurements. The value of the stability parameter calculated by ultrasonic measurements after the removal of Sr²⁺ ions from the contaminated solution was similar to that of double distilled water whose stability was used as reference. The outcomes of the batch experiments and the parameters obtained from Langmuir and Freundlich models indicated that the HAp nanoparticles had a strong affinity for the elimination of Sr²⁺ ions from polluted solutions. These results emphasized that HAp nanoparticles could be excellent candidates in the development of new technologies for water remediation. More than that, the outcomes of the cytotoxic assays proved that HAp nanoparticles did not induce any noticeable harmful effects against HeLa cells and did not affect their proliferation after 1 day and 7 days of incubation.

Keywords: biological properties; decontamination; hydroxyapatite; powder; strontium.

Grants and funding

PN-III-P2-2.1-PED-2019-0868, contract number 467PED/2020/Unitatea Executiva Pentru Finantarea Invatamantului Superior a Cercetarii Dezvoltarii si Inovarii