Adsorption Properties of CS/PAM/Fe(III) Complex for Phosphate Removal from Water

The adsorption of phosphate was conducted by the complex of chitosan/polyacrylamide/ferric(CS/PAM/Fe(III)) prepared. The SEM images and XPS spectra confirmed the successful adsorption of phosphate. The adsorption process was studied by varying the influencing aspects like pH, co-existing ions, contact time, and initial phosphate concentration. The experimental results indicate that the adsorptive capacity decreases with the increase of pH. However, it is commendable that there is still a adsorption capacity of more than 5 mg/g when the pH is 8–11. The adsorption kinetics can be accurately described by the pseudo-second-order model and is controlled by both chemisorption and surface diffusion. The adsorption process is a single layer adsorption. This paper proposed that the adsorption mechanism of CS/PAM/Fe(III) complex is the joint action of electrostatic attraction and ligand exchange.