含钙聚硅氯化铁铝的表征与絮凝研究

CHARACTERIZATION OF CALCIUM-CONTAINING POLYALUMINUM-FERRIC-SILICATE-CHLORIDE AND ITS FLOCCULATING

用X粉晶衍射、红外光谱对以Ca(OH)2为碱化剂合成的含硅聚合氯化铝铁(PAFSCCa)、比较样聚合氯化铝铁(PAFCCa)、及其合成前体聚合氯化铝(PACCa)、聚合氯化铁(PFCCa)的低温干燥样进行了表征。XRD衍射结果显示,PAFSCCa中有Ca-Si-O-Al化合物存在,加热可促进Ca-Si-O-Al化合物的结晶和生长。Si/Al摩尔比在1∶1时有利于Ca(Ⅱ)、Fe(Ⅲ)、Al(Ⅲ)与OH-之间的共聚,无论是在加热、常温合成条件下,PAFSCCa中均有短程有序而长程无序的Ca(Ⅱ)、Fe(Ⅲ)、Al(Ⅲ)羟合物大量存在。Ca-Si-O-Al化合物的存在会抑制Ca-O-Fe之间的键合,破坏Fe(Ⅲ)羟合物的结晶,但促进低聚合度Fe(Ⅲ)羟合物的生成。红外光谱证实,PAFSCCa中硅铝之间通过Si-O-Al氧桥的键合程度随Si/Al摩尔比的增加而上升。在Si/Al摩尔比1∶1及加热合成条件下,硅铝之间通过Si-O-Al氧桥的键合程度最高。絮凝实验证实PAFSCCa水解形成絮体时,含硅高的样品其絮体更大,絮凝效果好,硅铝共聚物对抑制微絮体再稳定的贡献大。

Mineralogical research can provide direct evidence for the species and morphs of hydroxyl polymeric aluminumferric chloride. The synthesized calcium-containing poly-aluminum-ferric-silicate-chloride （PAFSCCa） and the comparative samples of calcium-containing polyaluminum ferric chloride （PAFCCa）, poly-aluminum chloride （PACCa） and calcium-containing poly-ferrie chloride （PFCCa） have been characterized by X-ray diffraction and Fourier transform infrared speetroeeopy. The XRD patterns display that there exists polymeric Ca-Si-O-Al in solutions of PAFSCCa, and heating can speed up the crystal growth of polymeric Ca-Si-O-Al. At Si/Al mol ratio 1 ： 1 the co-aggregating between Ca（ Ⅱ ）, Fe（ Ⅲ ）, and Al （ Ⅲ ） with OH- is promoted. Under the synthetic conditions of heating and normal atmospheric temperature, there are large quantities of short range-order but long range-disorder hydroxyl radicals or polymeric mieelle of Ca（ Ⅱ ）, Fe（ Ⅲ ）, and Al（ Ⅲ ） in PAFSCCa solutions. Ca-Si-O-Al crystal nucleus in PAFSCCa solutions can cheek the bond of Ca-O-Fe and improve the formation of simple Fe（ Ⅲ ） hydroxyl polymeric but restraint their crystallization power. Infrared spectroscopy data show that the bonding degree between Si and Al by oxy-bridge of Si-O-Al tends to increase with increasing Si/Al tool ratio, and reaches the maximun under the condition of heating and Si/Al tool ratio=1：1. Coagulation-fleeeulation results showed that, as compared with PAFCCa, PACCa and PFCCa, the PAFSCCa gives a better turbidity removal effeet; the more the silicate in it, the larger the hydrolyte morphs in water solutions. Coagulation-floeeulation results also proved that the hydroxyl polymeric of Si-Al is of domination for curbing re-stabilization of miero-hydrolyzate in water treatment.