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钛酸盐纳米管(TNTs)由于具有较大的比表面积和优异的离子交换性能,显示出对重金属和阳离子染料高效的吸附性。文章通过一步水热法合成了粉末活性炭负载的钛酸纳米管(TNTs/PAC)材料,并应用于对铅离子(Pb)和阳离子染料亚甲基蓝的吸附。TNTs/PAC对Pb(Ⅱ)和MB都体现了很快的动力学,60min即可达到吸附平衡且符合准二级反应动力学(R~2=1)。吸附等温线符合Langmuir模型(R~2>0.998),拟合的单层饱和最大吸附量Pb(Ⅱ)为318.5mg/g,MB为234.5mg/g。Pb(Ⅱ)在TNTs@PAC上的吸附受溶液pH影响较大,碱性条件由于材料表面带更多的负电荷而利于吸附。TNTs@PAC对两种污染物的主要吸附机理为金属和染料阳离子与TNTs层间Na~+和H~+的交换作用。另外,该材料经EDTA解吸或紫外光照再生后易于循环利用。高效的吸附性能与良好的可再生性使该材料在修复重金属及染料污染水体方面成为一种极具前途的纳米复合材料。
Titanate nanotubes (TNTs) exhibit high efficiency of adsorbing heavy metals and cationic dyes due to their large specific surface area and excellent ion exchange performance. In this paper, powdered activated carbon supported titanate nanotubes (TNTs / PAC) materials were synthesized by one-step hydrothermal method and applied to the adsorption of lead (Pb) and cationic methylene blue. TNTs / PAC showed very fast kinetics for both Pb (II) and MB, and equilibrium was reached after 60 min and was in accordance with quasi-second order reaction kinetics (R ~ 2 = 1). The adsorption isotherm fitted the Langmuir model (R ~ 2> 0.998). The maximum monolayer adsorption capacity of Pb (Ⅱ) was 318.5 mg / g and MB was 234.5 mg / g. The adsorption of Pb (Ⅱ) on TNTs @ PAC is strongly influenced by the pH of the solution. The alkaline conditions favor the adsorption due to more negative charges on the surface of the material. The main adsorption mechanism of TNTs @ PAC on the two pollutants is the exchange of Na ~ + and H ~ + ions between metal and dye cations and TNTs. In addition, the material is easily recycled after being desorbed by EDTA or regenerated by UV light. Efficient adsorption and good reproducibility make this material a promising nanocomposite in the repair of heavy metals and dyes that pollute the water.