Synthesis of Modified Chitosan Gel Beads and Adsorption Performance of Cu(II)

In the present study, millimeter CS-TPP@MnFe 2 O 4 gel beads (particle size 3–4 mm) were prepared by the sol-gel process using the embedding method, and its performance of Cu(II) and influence factors were studied. The effect of various parameters such as the gel bead addition amount, adsorption time, temperature, pH, and competitive substances (anion and cationic) was studied. The surface and properties of gel beads were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The experimental results showed that the optimal pH for adsorption of Cu(II) by CS-TPP@MnFe 2 O 4 was 5–7, the adsorption of Cu(II) reached equilibrium at 24 h, and the maximum adsorption capacity could reach 125.70 mg g −1 at 298.15 K by Langmuir isotherm model. K + , Na + , Cl − , NO 3 − , and SO 4 2− had little effect on the adsorption, and Ca 2+ , Mg 2+ , and H 2 PO 4 − inhibited the adsorption, and SiO 3 2− and humic acid (HA) promoted the adsorption of Cu(II) by the adsorbent. After five adsorption-desorption experiments, the desorption rate of gel beads reached 89.3%, and the adsorption capacity of Cu(II) was still high. In conclusion, the CS-TPP@MnFe 2 O 4 gel beads are a type of stable and effective materials to remove Cu(II) from water.