Hu Chengzhi, Liu Huijuan, Qu Jiuhui, Wang Dongsheng, Rut Jia
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Environ Sci Technol. 2006 Jan 1;40(1):325-31.
The coagulation behavior of aluminum salts in a eutrophic source water was investigated from the viewpoint of Al(III) hydrolysis species transformation. Particular emphasis was paid to the coagulation effect of Al13 species on removing particles and organic matter. The coagulation behavior of Al coagulants with different basicities was examined through jar tests and hydrolyzed Al(III) speciation distribution characterization in the coagulation process. The results showed that the coagulation efficiency of Al coagulants positively correlated with the content of Al13 in the coagulation process ratherthan in the initial coagulants. Aluminum chloride (AICl3) was more effective than polyaluminum chloride (PACI) in removing turbidity and dissolved organic matter in eutrophic water because AlCl3 could not only generate Al13 species but also function as a pH control agent in the coagulation process. The solidstate 27Al NMR spectra revealed that the precipitates formed from AlCl3 and PACl were significantly different and proved that the preformed Al13 polymer was more stable than the in situ formed one during the coagulation process. Through regulating Al speciation, pH control could improve the coagulation process especially in DOC removal, and AlCl3 benefited most from pH control.
从铝（III）水解形态转化的角度研究了铝盐在富营养化水源水中的混凝行为。特别强调了Al13形态对去除颗粒和有机物的混凝效果。通过烧杯试验和混凝过程中水解铝（III）形态分布表征，研究了不同碱度的铝混凝剂的混凝行为。结果表明，铝混凝剂的混凝效率与混凝过程中Al13的含量呈正相关，而不是与初始混凝剂中的Al13含量呈正相关。在去除富营养化水中的浊度和溶解性有机物方面，氯化铝（AlCl3）比聚合氯化铝（PACI）更有效，因为AlCl3不仅能生成Al13形态，还能在混凝过程中起到pH调节剂的作用。固态27Al核磁共振光谱表明，由AlCl3和PACI形成的沉淀物有显著差异，证明在混凝过程中预先形成的Al13聚合物比原位形成的更稳定。通过调节铝形态，控制pH值可以改善混凝过程，特别是在去除溶解性有机碳方面，AlCl3从pH值控制中受益最大。
