Sr2+ adsorbents produced by microfluidics

In this paper, hydroxyapatite (HAP) nanoparticles (NPs) were synthesized by continuous flow using a 3D printed microreactor. The HAP NPs mostly consisted of acicular shape NPs and were mixed with chitosan (CS) to obtain precursor solution for the preparation of HAP/CS microspheres by electrospray method. The hybrid microspheres were used as economical adsorbents to remove Sr 2+ from aqueous solution. The effects of different adsorption parameters on the adsorption of Sr 2+ by HAP/CS were studied, including pH value, contact time, the dosage of HAP/CS, and coexisting ions. Adsorption of Sr 2+ using HAP/CS can accomplish in 4 h, and the saturated adsorption capacity was 234.20 mg g −1 . Langmuir isotherm model can describe the Sr 2+ adsorption process well, and the adsorption kinetics data were analyzed using the pseudo-second-order model, Weber–Morris intraparticle diffusion model and McKay equation. The adsorption amount showed no significant changes at 4 ≤ pH ≤ 10. The results suggest that HAP/CS could probably be used as an efficient and economical material to remove Sr 2+ from radioactive wastewater.