模拟扰动条件下太湖水体悬浮物的结构特性

Structural Characteristics of Suspended Solids in Taihu Lake Under Simulative Disturbing Conditions

设计了1个水体扰动模拟实验装置，通过该装置中的光散射分析仪和图象采集、分析系统，能在线记录底泥受到不同强度扰动时水体中悬浮颗粒物的变化过程．利用该装置，研究了太湖梅梁湾3个采样点的底泥在受到不同强度扰动后，水体浊度变化规律和悬浮颗粒物结构特性．结果表明，底泥含水率及粒度分布对底泥受扰动后再悬浮的潜力有较大影响，含水率越高，再悬浮的潜力越大．随着扰动强度增大，水体的浊度相应增加，水体中悬浮颗粒物中值粒径也增大，分别从6．63，5．79，5．51μm上升到12．49，11．38，13．33μm．悬浮颗粒物图象分析表明，颗粒物在扰动中发生聚集、絮凝过程．颗粒物图象的形态学分析表明，悬浮颗粒物形状呈现分形现象，颗粒物的长短比在1．27．1．52之间，分形维数D2则在1．72～1．94之间．

An equipment was designed to simulate the disturbance of water. The equipment includes photometric dispersion analyzer （PDA2000）, images gathering and analysis system which can record the change process of suspended particulate under different intensity conditions. Using this installment, the change of water turbidity and structural characteristics of suspended particulate of three sediments in Meiliang Bay, Taihu Lake, were studied under different disturbing intensities. The results showed that the re-suspension potential of sediment was influenced by moisture content and distribution of granularity, the moisture content is higher, the re-suspension is more posaible. With the increasing of disturbance intensity, the turbidity increased, the median granularity of particulate matter in the water increased from 6.63 μm, 5.79 μm and 5.51 μm to 12.49 μm, 11.38μm and 13.33μm respectively. The morphological analysis of particulate images showed that the shape of the particulate presents fraetal phenomenon, the long-short ratio of particulate were between 1.27 to 1.52 and fraetal dimension were between 1.72 to 1.94.