Purification and characterization of Al13 species in coagulant polyaluminum chloride.
Purification and characterization of Al13 species in coagulant polyaluminum chloride.
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DOI：
10.1016/s1001-0742(09)60005-x
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发表时间：
2009
影响因子：
6.9
通讯作者：
B. Gao;Yong-bao Chu;Q. Yue;Yan Wang
中科院分区：
文献类型：
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作者：
B. Gao;Yong-bao Chu;Q. Yue;Yan Wang
采用四种方法对纳米Al_(13)进行分离提纯，并用Al-Ferron定时络合分光光度计、~(27)Al-核磁共振和透射电子显微镜对其进行了分析。通过烧杯实验考察了纳米Al13、聚合氯化铝(PAC)和AlCl3在合成水中的混凝效果。研究了纳米Al13、PAC和AlCl3对高岭土悬浮液的凝聚动力学过程和凝聚状态。实验结果表明，凝胶柱层析法对低铝浓度的PAC溶液的分离效率最高。乙醇-丙酮法操作简单，能分离不同铝浓度的PAC溶液，而硅烷基化白块柱层析法只能分离低铝浓度的PAC溶液。SO42-−/Ba2+置换法可以分离铝浓度较高的聚合氯化铝溶液，但在分离过程中会引入额外的无机阳离子和阴离子。混凝效率和动态实验结果表明，高带正电物种的纳米Al_(13)是混凝过程中电中和的主要形态，能有效降低混凝过程中的浊度，提高有效颗粒的碰撞速率。它的混凝速度和所形成的混凝剂的粒度在本研究中具有最大的价值。
Nano-Al13was separated and purified by four methods to investigate its characteristic, and was analyzed by Al-Ferron timed complexation spectrophotometer,27Al-NMR (nuclear magnetic resonance), and transmission electron microscopy (TEM). Coagulation efficiency of nano-Al13, polyaluminum chloride (PAC), and AlCl3in synthetic water were also investigated by jar test. The dynamic process and aggregation state of kaolin suspensions coagulating with nano-Al13, PAC, and AlCl3were also investigated. The experimental results indicated that the efficiency of gel column chromatography method was the highest for separating PAC solution with low Al concentration. Ethanol and acetone method was simple and could separated PAC solution with different Al concentrations, while silicon alkylation white block column chromatography method could separate PAC solution only with low Al concentration. The SO42−/Ba2+displacement method could separate PAC solution with high Al concentration, but extra inorganic cation and anion could be introduced into the solution during the separation. The coagulation efficiency and dynamic experimental results showed that nano- Al13with a high positive-charged species was the main species of electric neutralization in coagulation process, and it could reduce the turbidity and increase the effective particles collision rate efficiently in coagulation process. Its coagulation speed and the particle size of coagulant formed were of greatest value in this study.