Enhanced reactivity of dicalcium phosphate dihydrate with fluoride ions by coating with apatite nanoparticles

Abstract

The formation of nanoscale precursors on the surface of dicalcium phosphate dihydrate (DCPD) is an important step in various methods; however, this process requires an unstable solution. Herein, we propose a simple method for the deposition of nanoscale fluorapatite (FAp) particles on the surface of DCPD particles using a weakly acidic, aqueous solution containing only calcium, phosphate, and fluoride ions (C-P-F solution). Repeated immersion in the same solution increases the amount of FAp deposition and almost no delay time is observed. Experimental results indicate that approximately 10 wt.% of FAp on the DCPD surface is optimal to enhance its reactivity with fluoride ions. Our results demonstrate an optimum FAp deposition amount on DCPD particles for improved reactivity with fluoride ions, and we achieved an improved surface of the DCPD particle for fluoride immobilization in wastewater and soil environments.

Defluoridation Proficiency of Ocimum tenuiflorum Based Bioadsorbent against Fluoride Toxicity in Drinking Water

“…The adsorbent in the residue was dried at 100 °C using hot air oven and then stored for adsorptive characterization studies. The defluoridation capacity of adsorbent was calculated using the formulae, 15 qe=(C o -C e ) /W ... (1) where q e is defluoridation capacity (mg/g); C o is initial concentration (mg/L); C e is equilibrium residual concentration (mg/L); W is adsorbent weight (g). All the results were computed using MS-Excel 2013 and Origin Pro 9.0 software.…”

“…Though fluoride is one of the nutritional needs to human, the same is the major principal hazard contaminant in drinking water which exists naturally. 1 The availability of fluoride concentration in drinking water defines whether it is beneficial or harmful. 2 World Health Organization (WHO) suggests drinking water should contain fluoride less than 1.5 mg/L 3 .…”