纳米Al13的分离方法及混凝效果动态过程的研究

以相同Al13含量、不同浓度的PAC为原料,利用乙醇-丙酮混合溶剂法、SO4^2-／Ba^2 沉淀置换法以及柱层析法分离提纯纳米Al13形态,同时利用Al-Ferron逐时络合比色法、^27Al-NMR等多种现代分析手段进行分析鉴定,比较其分离效果,并采用烧杯实验法和透光率脉动检测技术对Al13形态以及PAC、AlCl3的絮凝效果及絮凝过程中絮集物形成和增长的变化差异作了对比性研究．实验结果表明,乙醇．丙酮混合溶剂法对Al13分离纯化效果最好,分离所得Al13平均粒径大,聚合程度高．柱层析法受柱体积的影响只对低浓度的PAC有较好的分离效果;SO4^2-／Ba^2 沉淀置换法虽具有较好的分离效果,但分离过程有其他杂质离子的加入,影响到产品品质．混凝效果和动态实验结果表明,Al13形态是在絮凝过程中起电中和作用的主要形态,具有较强的除浊及脱色能力,在混凝过程中当絮体受到剪切力的破坏时Al13形态比PAC和AlCl3具有更强重新絮凝的能力．

The separating method and dynamic processes investigation on nano Al13 species

The Al_ 13 species were separated and purified from a series of poly-aluminum chloride(PAC) solutions, which had the same Al_ 13 percentage and different total Al concentration, by using column chromatography method, ethanol-acetone resolving method, and SO 2-_4/Ba 2+ displacement method. The Al_ 13 species yield was characterized by Al-Ferron timed complexation spectrophotometry, 27Al-NMR and ZATESIZER 3000HSA. Coagulation efficiency of Al_ 13, PAC and AlCl_3 in synthetic water was also compareed by Jar tests. And the dynamic process and aggregation state of Kaolin suspensions coagulating with the three coagulants were investigated by using a photometric dispersion analyzer (PDA). The experimental results indicated that, the precipitation with ethanol-acetone resolving method gave the best Al_ 13 separation results comparing with the other two methods. And the mean particle diameter of Al_ 13 species was the biggest, and the polymerization degree was the highest. Moreover, column chromatography method could give better separation efficiency only for low concentration of PAC. Impurity ions could be inducted by SO 2-_4/Ba 2+ displacement method. The coagulation effects and dynamic experimental results showed that the Al_ 13 was a high positive-charged species and was good at turbidity and color removal. The dynamic process results showed that the Al_ 13 species also had the best recovery capability from shear-broken than PAC and AlCl_3, because its conformation could take more effective in charge neutralization.