Abstract:

Extracting effective components from red mud and using them as raw materials to prepare flocculants is one of the effective ways for the comprehensive utilization of red mud. Poly silicate aluminum ferric flocculant(PSAF)was prepared by copolymerization method with using red mud as raw material. The optimal preparation conditions and suitable application conditions of PSAF were investigated,and it was applied to the treatment of simulated and actual fluorine-containing wastewater. PSAF was characterized by X-ray diffraction(XRD), infrared spectroscopy(FT-IR), and X-ray electron spectroscopy(XPS). The results showed that poly silicic acid successfully complexed with aluminum and ferric to prepare an amorphous PSAF. The flocculation experiment results showed that the optimal preparation conditions for PSAF were n(Al+Fe):n(Si)=1:1, n(Al):n(Fe)=5:1, and alkalinity was 0.5. The PSAF prepared under these conditions was suitable for treating simulated fluorine-containing wastewater under the following conditions:dosage of 0.66 mmol/L, wastewater pH≈7, and flocculation sedimentation time of 20 minutes. Two types of wastewater were treated under suitable application conditions. The turbidity and F^- removal rates of simulated fluorinated wastewater were 97.6% and 80.8%, respectively. The turbidity and F^- removal rates of actual fluorinated wastewater were 77.4% and 56.6%, respectively. The flocculation effect was superior to the two commercially available flocculants, poly aluminum chloride(PAC) and poly ferric sulfate(PFS), which indicated that PSAF had high practical value.

Key words: red mud, poly silicate aluminum ferric, fluorine containing wastewater, flocculant

摘要：

对赤泥中有效成分进行提取并以此为原料制备絮凝剂，是赤泥综合利用的有效途径之一。以赤泥为原料，采用共聚法制备了聚硅酸铝铁（PSAF）絮凝剂，探究了PSAF的最佳制备条件和适宜使用条件，并将其应用于模拟含氟废水和实际含氟废水处理。通过X射线衍射仪（XRD）、红外光谱仪（FT-IR）和X射线电子能谱仪（XPS）对PSAF进行表征，结果表明聚硅酸与铁、铝成功络合，制备了一种无定形的PSAF。絮凝实验结果表明，PSAF最优制备条件：n（Al+Fe）∶n（Si）=1∶1，n（Al）∶n（Fe）=5∶1，碱化度为0.5。此条件下制备的PSAF对模拟含氟废水进行处理，适宜的使用条件：PSAF投加量为0.66 mmol/L，废水pH≈7，絮凝沉淀时间为20 min。该条件下对两种废水进行处理，模拟含氟废水浊度和F^-去除率分别为97.6%和80.8%，实际含氟废水浊度和F^-去除率分别为77.4%和56.6%，絮凝效果均优于聚合氯化铝（PAC）和聚合硫酸铁（PFS）两种市售絮凝剂，可见PSAF具有较高的使用价值。

关键词: 赤泥, 聚硅酸铝铁, 含氟废水, 絮凝剂

CLC Number: 

• X703.1