负载硅藻土的固体聚合硫酸铁的制备及结构表征

Preparation and Structural Analysis of Diatomite-Supported SPFS Flocculant

以工业副产品七水硫酸亚铁(FeSO4.7H2O)为原料,制备液体聚合硫酸铁(PFS)絮凝剂,再与硅藻土复合,在一定的温度下,通过真空烘箱干燥制备固体PFS。通过红外光谱及扫描电镜(SEM)对其结构表征,结果表明:负载硅藻土后的PFS中很可能有新的基团键生成,在PFS之间形成了新的键桥作用;硅藻土中多种金属物质和部分PFS相互作用形成了复合型铁系聚合体,以及硅藻土中载体吸附团聚作用的结果,使絮凝剂的分子结构变大,增强了复合絮凝剂吸附架桥和卷扫的功能。通过正交实验研究其合成优化工艺条件为:FeSO4.7H2O与硅藻土的质量比为43∶1,反应时间为1 h,反应温度为55℃;合成产物对生活污水的处理具有良好的絮凝性能,COD和浊度的去除率分别可达80.00%和99.98%。

In the presetn study,polymerized ferric sulphate（PFS） flocculant was prepared and tested.In the preparation of PFS flocculant,industrial by-product ferrous sulfate heptahydrate（FeSO4·7H2O） was reused as the main material.By composition with diatomite and drying up at certain temperature in vacuum drying oven,solid PFS flocculant was produced.Structural characteristics of the new flocculant product were examined through infrared spectroscopy and scanning electron microscopy（SEM）,which showed that by compositing with diatomite,new group bridging emerged in the structure of PFS,which made the bond of groups stronger.In addition,part of the metalic contents in diatomite was polymerized with PFS,the product of which was polymerized ferric complex.Furthermore,the absorbing and agglomerating capacity of the diatomite carrier was significant.Considering the factors listed above,the new solid polymerized ferric sulphate（SPFS） flocculant was characterized with a larger molecule structure and enhanced absorbing,bridging and rolling sweep capacities.Through orthogonal experiment,optimum conditions of synthesis were as follows： the ratio of FeSO4·7H2O/diatomite in weight was 43/1,the reaction time is 1 h and the reaction temperature is 55 ℃.By wastewater treatment experiment,it was found that the synthetic products showed good flocculation performance in the treatment of domestic sewage,the removal of COD was 80.00% and the removal of turbidity was 99.98%.