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研究了丁二酸酐修饰的香蕉纤维素对水溶液中Pb~(2+)的吸附特性,明确改性香蕉纤维素吸附剂的添加量、溶液pH值、温度及Pb~(2+)初始质量浓度对吸附效果的影响,并探讨吸附过程的动力学特征。结果表明,改性香蕉纤维素对Pb~(2+)吸附的最佳pH值为5.0,单位吸附量随吸附剂添加量的减小、Pb~(2+)初始质量浓度的增加而增加。在优化试验条件下,1 g/L的吸附剂在30℃时,对pH5的50 m L 100 mg/L Pb~(2+)溶液中,单位吸附量达到44.3 mg/g。改性香蕉纤维素对Pb~(2+)的吸附动力学模型符合准二级动力学模型,拟合系数在0.999以上。结合傅里叶红外光谱、扫描电镜-热重分析和X射线衍射分析手段,发现改性香蕉纤维素对Pb~(2+)的吸附以物理吸附为主,同时包括螯合作用、离子交换等化学吸附及颗粒内扩散等过程。
The adsorption characteristics of succinic anhydride-modified banana cellulose on Pb 2+ in aqueous solution were studied. The effects of additive amount of banana cellulose adsorbent, pH value of solution, temperature and initial Pb 2+ concentration On the adsorption effect, and to explore the kinetic characteristics of the adsorption process. The results showed that the optimum pH value of modified banana cellulose for Pb 2+ adsorption was 5.0, and the unit adsorption capacity increased with the increase of initial concentration of Pb 2+ with the decrease of adsorbent dosage. Under optimized experimental conditions, the adsorption capacity of 1 g / L adsorbent reached 44.3 mg / g in 50 m L 100 mg / L Pb 2+ solution at pH 5 at 30 ℃. The adsorption kinetics model of modified banana cellulose to Pb 2+ conforms to the quasi-second-order kinetic model, and the fitting coefficient is above 0.999. Combined with Fourier transform infrared spectroscopy, scanning electron microscopy - thermogravimetric analysis and X-ray diffraction analysis, it was found that the adsorption of Pb 2+ by modified banana cellulose was mainly by physical adsorption, including chelation, ion exchange and the like Chemical adsorption and intra-particle diffusion processes.