Optimization of Adsorption Process and Characterization of Cu²⁺ and Cd²⁺ by Athelia rolfsii Polysaccharide

To explore the adsorption on copper and cadmium heavy metal ions in water by using Athelia rolfsii polysaccharide as a biosorbent. On the basis of single factor experiments,the orthogonal experiment was used to optimize the adsorption effect of Cu²⁺ and Cd²⁺ by AEPS. The surface topography of polysaccharides before and after adsorption of heavy metal ions were characterized and analyzed by scanning electron microscope(SEM),X-ray energy dispersive spectrometer(EDS)and Fourier transform infrared spectroscopy(FTIR),and the adsorption mechanism of AEPS on Cu²⁺ and Cd²⁺ were initially revealed. The results of the optimal conditions for Cu²⁺ adsorption were pH4.5,AEPS concentration 1.5 g/L,adsorption temperature 40 ℃,and adsorption time 45 min,the Cu²⁺ adsorption rate was 88.27%. The optimal conditions for Cd²⁺ adsorption were pH6.5,polysaccharide concentration 1.5 g/L,adsorption temperature 45 ℃,and adsorption time 60 min,the Cd²⁺ adsorption rate was 77.81%. The results of SEM,EDS and FTIR indicated that the O-H,C-H,C-O and CCO functional groups in AEPS were involved in the adsorption reaction,and the surface structure of AEPS adsorbing Cu²⁺ and Cd²⁺ also changed significantly. The results showed that AEPS had a good adsorption effect on Cu²⁺ and Cd²⁺.