Coagulation Behavior of Aluminum Salts in Eutrophic Water: Significance of Al13 Species and pH Control

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• 作者：Chengzhi Hu ; Huijuan Liu ; Jiuhui Qu ; Dongsheng Wang ; and Jia Ru
• 刊名：Environmental Science & Technology
• 出版年：2006
• 出版时间：January 1, 2006
• 年：2006
• 卷：40
• 期：1
• 页码：325 - 331
• 全文大小：167K
• 年卷期：v.40,no.1(January 1, 2006)
• ISSN：1520-5851

文摘

The coagulation behavior of aluminum salts in a eutrophicsource water was investigated from the viewpoint of Al(III) hydrolysis species transformation. Particular emphasiswas paid to the coagulation effect of Al₁₃ species onremoving particles and organic matter. The coagulationbehavior of Al coagulants with different basicities wasexamined through jar tests and hydrolyzed Al(III) speciationdistribution characterization in the coagulation process.The results showed that the coagulation efficiency of Alcoagulants positively correlated with the content of Al₁₃ inthe coagulation process rather than in the initial coagulants.Aluminum chloride (AlCl₃) was more effective thanpolyaluminum chloride (PACl) in removing turbidity anddissolved organic matter in eutrophic water because AlCl₃could not only generate Al₁₃ species but also function asa pH control agent in the coagulation process. The solid-state ²⁷Al NMR spectra revealed that the precipitatesformed from AlCl₃ and PACl were significantly differentand proved that the preformed Al₁₃ polymer was more stablethan the in situ formed one during the coagulationprocess. Through regulating Al speciation, pH controlcould improve the coagulation process especially in DOCremoval, and AlCl₃ benefited most from pH control.