Facile fabrication of polyacrylic acid functionalized carboxymethyl chitosan microspheres for selective and efficient removal of Ni(II) from multicomponent wastewater

The unpurified discharge of highly toxic Ni(II)-contained wastewater represents a serious threat to ecological environment and human health. In this study, a novel polyacrylic acid (PAA) functionalized carboxymethyl chitosan microspheres (PAA-CMCs), synthesized by grafting copolymerization method, was used to removal Ni (II) from wastewater. The PAA-CMCs was characterized by SEM, elemental analyzer, FT-IR and XPS. The equilibrium data was better described by L-F model with high coefficients of determination (R-2 > 0.991). Meanwhile, the maximum Ni(II) adsorption capacity of PAA-CMCs deduced from L-F model was as high as 200.588 mg g(-1). Moreover, the selective capacity was investigated by batch adsorption experiments and its mechanism was revealed by electronegativity and electrophilic index. Besides, the excellent regeneration performance of PAA-CMCs was verified after six adsorption-desorption cycles. Thus, the newly developed PAA-CMCs is a promising candidate for deep treatment of heavy metal-contained wastewater.