PDMDAAC-PFS复合絮凝剂处理硅藻土悬浊液的絮体分形特征

采用扫描电镜考察了聚二甲基二烯丙基氯化铵-聚合硫酸铁复合絮凝剂(PDMDAAC-PFS)处理硅藻土悬浊液的絮体形貌,并与单独使用PDMDAAC和PFS产生的絮体进行比较.运用密度-密度相关函数计算了絮体的分维,探讨了絮体的结构、分维与沉降速度的关系.结果表明,使用PDMDAAC-PFS产生的硅藻土絮体分维为1.89,比单独使用PFS和PDMDAAC产生的絮体分维大(分维分别为1.67和1.55),其沉降速度比使用PFS产生的絮体快;絮体结构为内部有较多内孔的网状结构,内孔的可渗透性可降低沉降阻力,提高沉降速度.图5,参9.

Fractal Characteristics of Diatomite Flocs Treated by Poly (Dimethyldiallylammonium Chloride)-Polyferric Sulfate Composite Flocculant

The images of diatomite flocs treated by poly (dimethyldiallylammonium chloride)-polyferric sulfate composite flocculant (PDMDAAC-PFS)were investigated by scanning electron microscope (SEM),and compared with those treated by PDMDAAC and PFS alone.The fractal dimensions of these flocs were calculated by density-density correlation function method,and the relationships between the structure and fractal dimension of flocs and its sedimentation velocity were discussed.The results show that fractal dimension of diatomite flocs treated by PDMDAAC-PFS is 1.89, which is higher than those treated by PFS and PDMDAAC (its fractal dimensions are 1.65 and 1.55,respectively),and show higher sedimentation velocity,and that the structures of diatomite flocs treated by PDMDAAC-PFS exhibit net structures with many inner holes whose permeability is benefit to decreasing sedimentation resistance and increasing sedimentation velocity.5figs.,9refs.