Cadmium Removal from Cadmium‐Containing Apatites by Ion‐Exchange Reactions

Abstract

The exchange reaction of cadmium by non-toxic metallic cation ions in a cadmium-containing apatite was studied. A cadmiumcontaining apatite with characteristics close to those of natural phosphate ore was synthesized. Copper and then zinc ions have been found to be the most effective elements for the exchange reaction. After 4 h of treatment at room temperature, 25 % and 14 % of cadmium were removed using 0.1 m solutions of copper and zinc ions, respectively. At 60 °C, cadmium removal efficiency improved considerably. For copper ions, the efficiency reached 53 %, while it arrived at 25 % for zinc ions. The equilibrium study shows that the two reactions are thermodynamically feasible but balanced reactions with little reaction progress for small cadmium content. The reaction can be well modeled by the shrinking-core model and is found to be controlled by the diffusion through the reacted layer.

3D-Printed Filters for Efficient Heavy Metal Removal from Water Using PLA@CS/HAP Composites

“…Consequently, the removal of heavy metal ions from water has garnered significant attention from researchers in recent years [2][3][4][5]. Over the past decades, several methods have been developed to address the removal of toxic heavy metal ions from wastewater, including chemical precipitation, ion exchange, membrane separation techniques, and adsorption [6][7][8][9]. However, many of these approaches suffer from limitations such as low removal efficiency and high energy consumption.…”