Characteristics and mechanism of Cu(II) adsorption on prepared calcium alginate/carboxymethyl cellulose@MnFe 2 O 4

A magnetic composite microsphere, calcium alginate (CA)/carboxymethyl cellulose (CMC)@MnFe 2 O 4, was prepared using CA and CMC encapsulated MnFe 2 O 4 through blending and cross-linking for the removal of Cu(II) from aqueous solution. The CA/CMC@MnFe 2 O 4 was characterized in detail by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and X-ray phosphorescence spectroscopy. In addition, various adsorption conditions including the initial pH of Cu(II) solution, equilibrium contact time, and initial Cu(II) concentration were tested. The adsorption data fit better to the Langmuir isotherm and follow the pseudo-second-order model, suggesting that it is a monolayer adsorption process with chemisorption as the rate-limiting step. The maximum adsorption capacity of the CA/CMC@MnFe 2 O 4 was 77.22 mg g −1 at 25 ℃ and pH 5. Cu(II) removal mechanisms of CA/CMC@MnFe 2 O 4 follow ion exchange as well as the formation of complexes as evidenced based on the microstructure analysis and adsorption data fitting.