聚硅硫酸铁絮凝剂的制备及絮凝效果的研究

分别以硫酸铁和聚合硫酸铁作为加入原料引入聚硅酸(PS),制备出两种聚硅酸硫酸铁絮凝剂(PFSS和PFS-PS),实验考察了两种絮凝剂的稳定性、它们应用于炼油厂污水的絮凝效果以及最佳絮凝条件,同时还与聚合硫酸铁絮凝剂(PFS)的絮凝效果进行了比较。结果表明,PFSS的稳定性优于PFS-PS,PFSS和PFS-PS两者的絮凝效果明显优于PFS,且PFSS的絮凝效果优于PFS-PS;在pH=6～9,PFSS9#投加量为50～62.5mg/L(以ρ(SiO2)计)时,浊度去除率为100%,COD去除率为55%左右,二者均可达到最佳絮凝效果。从稳定性、絮凝效果和经济角度考虑,用先混合再羟基化方法制备的PFSS可作为首选聚硅铁絮凝剂。

Preparation of Polymetric Ferric Silicate Sulphate and Its Application in Flocculating Effect

PFSS and PFS-PS, two kinds of polymeric ferric silicate sulphate flocculants, were prepared by adding ferric sulphate and poly-ferric sulphate (PFS) to polysilicate (PS) respectively. The stability of these two flocculants, the flocculating efficiency of petrochemical wastewater treatment and the optimum flocculating conditions were all investigated in experiments. The results show that the flocculant's stability and the flocculating efficiency of PFSS are prior to that of PFS-PS; the flocculating efficiency of the above two flocculants are better than that of PFS; and the optimum flocculation conditions can be obtained while the concentration of PFSS and PFS-PS added are 50 mg/L(in the equivalent of SiO2) at pH=6～9. In the view of flocculant's stability, practical efficiency and economical concern, PFSS is considered as a better polymetric ferric silicate sulphate flocculant than PFS-PS.