作　　者： ; ; ; ; ;

机构地区： 广东工业大学建设学院

出　　处： 《泥沙研究》 2005年第1期73-78,共6页

摘　　要： 处理含沙量在20～30kgm3以上的高浊度水,必须采用高分子絮凝剂进行固-液分离。在这些工艺中架桥絮凝是最常见的颗粒凝聚机理。然而,对有关架桥絮凝体的构造特性知之甚少。本文采用沉降技术并结合黄河泥沙架桥絮凝体的电镜照片,对絮体分形特征进行了研究。从沉降实验数据求得稳定态泥沙絮体质量分维D3=1930±005,这表明絮体具有高度多孔的分形构造。运用分维模型及图像处理技术得到的二维分维值D2证明,如果假定所有的泥沙絮体在层流范围沉降,则会低估了质量分维值。 For high-turbidity waters with up to 20～30kg/m3 of sediment, one must use high molecular weight polymeric flocculants to separate solid from liquid. Bridging flocculation is the most common particle aggregation mechanism in these processes. However, there is little knowledge about the structure formation of the aggregates. This paper describes the characteristics of fractal structure of bridging flocculated aggregates by using settling technique integrating with SEM photographs of Yellow-River sediment flocs. For bridging flocculated aggregates of Yellow-River sediment at the steady-state, the value of mass fractal dimensions D-3 calculated from the settling experimental data is 1.930±0.05 which indicates higher porosity and larger impermeability of fractal structures of aggregates. By using fractal model integrated with photographic technology, one can obtain a fractal dimension value D-2 in a two dimensions space. The value of D-2 proves that an underestimated fractal dimension value if laminar flow is wrongly assumed to apply to all aggregates.

关 键 词： 黄河泥沙 架桥絮凝 阳离子高分子聚合物 絮体结构 分形 沉降

领　　域： [环境科学与工程] [水利工程]