废弃烟滤嘴制备醋酸纤维素微球及其对Pb(Ⅱ)的吸附性能

Preparation of Cellulose Acetate Microspheres from Waste Cigarette Filters and Its Adsorption Properties for Pb^(2+)

采用双重乳液溶剂挥发法与气体发泡技术相结合的方法将从废弃卷烟滤嘴中再生得到的醋酸纤维素进行改性,制备出醋酸纤维素多孔微球。通过扫描电镜、氮吸附和压汞法考察了内水相发泡剂用量和搅拌速度对微球形貌、比表面积和孔结构的影响,并进一步研究了其对重金属Pb^(2+)的吸附性能。结果表明:随发泡剂用量增大,微球粒径逐渐变大,比表面积先增大后稍有下降,由闭孔转化为贯通孔;随搅拌速度加大,微球粒径逐渐减小,比表面积呈增大趋势,高速搅拌下具有更多的贯通孔结构。静态吸附结果显示,所制备醋酸纤维素多孔微球对Pb^(2+)吸附量可达57.6 mg/g,远远优于未采用发泡剂技术所得微球的吸附性能。吸附动力学以及吸附等温实验表明该醋酸纤维素微球对Pb^(2+)的吸附符合准二级动力学模型和Freundlich吸附等温模型。

The cellulose acetate regenerated from waste cigarette filters was modified by the combination of dual emulsion solvent evaporation and gas foaming technology to prepare the cellulose acetate porous microspheres.The effects of the amount of foaming agent and stirring speed on the morphology,surface area and pore structure of the microsphere were investigated by scanning electron microscope(SEM),N 2 adsorption and mercury intrusion porosimetry(MIP).The results showed that the diameter of microsphere gradually increased,the surface area increased at first and then decreased slightly and closed pores transformed to through pores with the adding of foaming agent.With the increment of stirring speed,the diameter of microsphere gradually decreased,and the surface area increased,leading to more through-holes structure appeared under high-speed stirring.The results of static adsorption revealed that the Pb^(2+)adsorption capacity of the cellulose acetate microspheres was up to 57.6 mg/g,which was much better than that of the microspheres without blowing technology.Adsorption kinetics and adsorption isotherm experiments showed that the Pb^(2+)adsorption of cellulose acetate microsphere was compliant with quasi-second-order kinetic model and Freundlich adsorption isothermal model.