Hydrothermal Synthesis of Melamine-Functionalized Covalent Organic Polymer-Blended Alginate Beads for Iron Removal from Water

The present study aimed to utilize the advantages of the porous covalent organic frameworks (COFs) by synthesizing in a usable bead form with alginate using hydrothermal method. The melamine-rich covalent organic polymer/alginate (MCOP-Alg) composite beads were utilized for iron removal. The maximum adsorption capacity of MCOP-Alg composite beads was achieved as 53.89 mg g(-1). The synthesized MCOP-Alg composite beads were characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis with mapping analysis, Fourier transform infrared, and Brunauer-Emmett-Teller studies. The various adsorption experiments such as contact time, solution pH, competing ions, and temperature have been optimized successfully for iron removal. The equilibrium result was demonstrated with Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) isotherms. The thermodynamic result indicates the endothermic and spontaneous nature The iron adsorption mechanism follows surface complexation with electrostatic attraction and ion-exchange. Fe(II)-adsorbed MCOP-Alg composite beads could be easily regenerated using 0.5 M HCl. The field study of MCOP-Alg composite beads was also examined.