天然水中可溶性硅酸与铝盐作用机理探讨

通过考察单核铝和溶解铝浓度的变化, 对天然水体中溶解性硅酸与铝盐的反应机理进行研究. 试验过程中, 采用8-羟基喹啉荧光分光光度法测定铝浓度并结合热力学计算进行机理验证. 结果表明: 单体硅酸和聚硅酸主要与溶液中的单核铝反应生成溶解性硅铝酸盐. 单体硅酸与单核铝的结合能力较弱; 聚硅酸与单核铝的结合能力则较强, 反应产物主要为二啮或三啮配合物. 溶液pH对反应过程有着重要影响, 偏碱性环境对硅酸与单核铝间的反应具有促进作用.

Reaction Mechanism of Soluble Silicic Acid with Aluminum in Natural Water

The reaction mechanism between soluble silicic acid and aluminum in natural water was studied by the detection of concentrations of monomer and soluble aluminum. The concentrations of aluminum were determined by an 8-hydroxyquinoline fluorometric method, and the mechanism was confirmed by thermo-dynamic calculation. The results indicated that both the monomer and polymer silicic acids mainly reacted with the monomer aluminum to form soluble aluminosilicates. The capacity of combination between mono-mer silicic acid and monomer aluminum was weak, while it was stronger between the polymer silicic acid and monomer aluminum and the products were mainly bidentate or tridentate coordination compounds. During the reaction process, pH played an important role that the reaction could be notably promoted in slightly alkaline solution.