磁性壳聚糖/多壁碳纳米管复合吸附剂吸附甲基橙的性能研究

以壳聚糖、多壁碳纳米管和磁性γ-Fe2O3粒子为原料,通过微乳化法制备出磁性壳聚糖/多壁碳纳米管复合吸附剂。运用XRD和VSM等手段对复合吸附剂进行了表征,并研究了吸附剂配比、吸附剂投加量、甲基橙初始浓度、pH、无机阴离子、温度等因素对甲基橙脱色效果的影响。结果表明,γ-Fe2O3磁性粒子和多壁碳纳米管被壳聚糖包裹;引入多壁碳纳米管显著提高了吸附容量;吸附剂的最佳投加量为0.6 g/L;甲基橙初始浓度增大,去除率下降,吸附量上升;酸性环境有利于吸附;降低温度有利于吸附;吸附动力学较好地符合拟二级动力学模型,分子内扩散模型是吸附控制机制之一;吸附等温线更符合Langmuir模型,最大单分子层吸附量为62.97 mg/g。

Adsorption of Methyl Orange by Magnetic Chitosan/Multi-walled Carbon Nanotubes Composite Adsorbent

Magnetic chitosan/multi-walled carbon nanotubes composite adsorbent was prepared by micro-emulsification method by introducing chitosan and multi-walled carbon nanotubes(MWCNT) as effective components and using γ-Fe2O3 particles as magnetic assisted separating agent.The adsorbent was characterized by XRD and VSM.The effects of adsorbent ratio,dose of adsorbent,initial concentration of methyl orange,initial pH value and temperature on the methyl orange adsorption were studied.The results showed that magnetic γ-Fe2O3 particles and MWCNT have been enwrapped by chitosan.The adsorption capacity was obviously increased due to the introduction of MWCNT.The optimal adsorbent dose was 0.6 g/L.The dye removal percentage decreased with the increase of initial concentration of methyl orange,while the adsorption capacity increased.Acidic environment was more favorable to adsorption.Adsorption process was exothermic.Kinetics data were better fitted by pseudo-second-order kinetic model,and intra-particle diffusion was not the only rate-determining process.Adsorption isotherm was better fitted by Langmuir isotherm,and its maximum monolayer adsorption capacity was 62.97 mg/g.