Removal of heavy metals and bacteria from aqueous solution by novel hydroxyapatite/zeolite nanocomposite, preparation, and characterization

Abstract

In this study, a HAp/NaP nanocomposite was prepared by adding a synthesized nano-hydroxyapatite to zeolite NaP gel in the hydrothermal condition and used for the removal of lead(II) and cadmium(II) ions from aqueous solution. HAp/zeolite nanocomposite was then characterized by Fourier transform infrared spectroscopy, X-ray diffraction and Rietveld method, scanning electron microscope, energy-dispersive X-ray analysis, and surface area and thermal analyses. Results suggested that the nanocomposite crystals of HAp were dispersed onto the zeolite external surface and/or encapsulated within the zeolite channels and pores. The potential of the composite in adsorption of heavy metals was investigated by using batch experiment. The metal concentration in the equilibrium Ce (mg/g) after adsorption with nanocomposite of HAp/NaP was analyzed using flame atomic adsorption spectrometry. The adsorption experiments were carried out at pH of 3–9. The influences of contact time, initial concentration, dose, and temperature on the adsorption of lead and cadmium ions were also studied. Results show that these nanocomposites have further adsorption related to NaP and HAp. They have great potential (about 95 %) for Pb(II) and Cd(II) adsorption at room temperature. The equilibrium process was described by Frendlich, Langmuir, Temkin, and Dubinin–Radushkevich (D-R) models. The kinetics data were successfully fitted by a pseudo-second-order model. The in vitro antibacterial activity of these composites was evaluated against Bacillus subtilis (as Gram-positive bacteria) and Pseudomonas aeruginosa (as Gram-negative bacteria) and compared with standard drugs that show inhibition on bacterial growth

Nanomaterials for the Removal of Heavy Metals from Wastewater

“…Zeolite is another kind of promising host and stabilizer for nanoparticles due to its high surface area, excellent ion exchange ability, hydrophilic, environment-friendly characteristic and simply controllable chemical properties [235]. Hydroxyapatite/zeolite nanocomposite (HAp/NaP) was prepared to treat Pb (II) and Cd (II) in water by batch method and the maximum adsorption capacities of Pb (II) and Cd (II) were 55.55 and 40.16 mg·g −1 respectively [236]. The adsorption kinetic could be correlated with the pseudo-second model perfectly.…”

A review: Analytical methods for heavy metals determination in environment and human samples

“…They used HAp/ NaP for the removal of lead(II) and cadmium(II) ions from aqueous solution. This nanocomposite was characterized by FTIR, X-ray, SEM, energydispersive X-ray analysis and thermal analyses [42]. Microwave-assisted method was used for synthesizing of graphene nanosheet/δ-MnO 2 (GNS/ MnO 2 ) composite.…”

Application of nanomaterials for the removal of heavy metals from wastewater

“…The nanocomposite was produced by the addition of synthesized nanohydroxyapatite in to zeolite nanoparticle gel within the hydrothermal condition to remove Cd 2+ and Pb 2+ ions. The nanocomposite crystal structures of hydroxyapatite were dispersed on to the external surface of zeolite and/or considerably encapsulates within pores and channels of zeolite and exhibited an excellent potential of about 95% to adsorb lead and cadmium at room temperature [20]. A novel re-usable nanocomposite based on the silver nano-assisted and nanocellulose pebbles to eliminate heavy metals (98.30% of Cr 3+ and 99.48% of Pb 2+ ) along with dyes and microbes from the aqueous solution [21].…”