Study on Preparation of Cross-linked Starch Microspheres（CSM）and Adsorption Capability to Cr（Ⅵ）

The cross-linked starch microsphere(CSM) was synthesized from starch by inverse suspension polymerization with N, N'-methylene-bis-acrylamide as cross-linking agent, cyclohexane as oil phase, potassium persulfate and sodium bisulfite(K₂S₂O₈-NaHSO₃) REDOX system as initiator and Span80 and tween60 as emulsifier. CSM was characterized by Fourier transform infrared spectroscopy(FTIR). The adsorption behavior of Cr(VI) on CSM was studied, and the influencing factors also were studied such as concentration of Cr(Ⅵ), mass of CSM and adsorption time. The Langmuir equation and Freundlich equation were simulated by the isotherm curves. The results showed that the surface of starch microsphere was rough and porous, and the crystallizability of starch microsphere decreased with the adsorption of Cr(Ⅵ) going on. The proper condition for CSM to adsorb Cr(Ⅵ) was that when the adsorption time was 70 min, the dosage of starch microsphere(CSM) 0.07 g, and the concentration of Cr(Ⅵ) 50 mg/L. The adsorption behavior of Cr(Ⅵ) on CSM followed Langmuir adsorption isotherm equation, and the correlation coefficient was 0.989 0.