Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, Sydney, NSW, 2232, Australia,
Environ Sci Pollut Res Int. 2014 Mar;21(5):3972-86. doi: 10.1007/s11356-013-2305-6. Epub 2013 Dec 3.
Economic adsorbents in bead form were fabricated and utilised for the adsorption of Al(3+) from aqueous solutions. Polyacrylonitrile (PAN) beads, PAN powder and the thermally treated PAN beads (250 °C/48 h/Ar and 600 °C/48 h/Ar-H2) were characterised using different techniques including Fourier transform infrared spectroscopy, X-ray diffraction, specific surface analysis (Brunauer-Emmett-Teller), thermogravimetric analysis as well as scanning electron microscopy. Effects of pH, contact time, kinetics and adsorption isotherms at different temperatures were investigated in batch mode experiments. Aluminium kinetic data best fit the Lagergren pseudo-second-order adsorption model indicating a one-step, surface-only, adsorption process with chemisorption being the rate limiting step. Equilibrium adsorption data followed a Langmuir adsorption model with fairly low monolayer adsorption capacities suitable for freshwater clean-up only. Various constants including thermodynamic constants were evaluated from the experimental results obtained at 20, 40 and 60 °C. Positive values of ΔH° indicated that the adsorption of Al(3+) onto all three adsorbents was endothermic with less energy input required for PAN powder compared to PAN beads and low-temperature thermally treated PAN. Negative ΔG° values indicated that the aluminium adsorption process was spontaneous for all adsorbents examined.
采用珠状形式的经济吸附剂从水溶液中吸附 Al(3+)。使用不同的技术对聚丙烯腈 (PAN) 珠、PAN 粉末和经热处理的 PAN 珠（250°C/48 h/Ar 和 600°C/48 h/Ar-H2）进行了表征，包括傅里叶变换红外光谱、X 射线衍射、比表面积分析（Brunauer-Emmett-Teller）、热重分析和扫描电子显微镜。在分批实验中研究了 pH 值、接触时间、动力学和不同温度下的吸附等温线的影响。铝动力学数据最符合 Lagergren 伪二阶吸附模型，表明这是一个一步、仅表面的吸附过程，其中化学吸附是速率限制步骤。平衡吸附数据遵循 Langmuir 吸附模型，单层吸附容量较低，仅适用于淡水净化。从在 20、40 和 60°C 下获得的实验结果评估了各种常数，包括热力学常数。ΔH°的正值表明，所有三种吸附剂对 Al(3+)的吸附都是吸热的，与 PAN 珠相比，PAN 粉末需要更少的能量输入，而低温热处理的 PAN 则需要更少的能量输入。负的ΔG°值表明，所有被检查的吸附剂的铝吸附过程都是自发的。
