基于不同疏浚绞刀结构的底泥污染物释放情况分析

Study of sediment contaminants release based on different dredging cutter structures

分别采用普通绞刀、加罩普通绞刀、螺旋绞刀和加罩螺旋绞刀进行疏浚模拟试验,通过比较疏浚点周围上覆水中各污染物浓度变化情况,分析不同结构绞刀的环保性能。结果表明：采用螺旋绞刀疏浚下,底泥中污染物释放量较采用普通绞刀疏浚时小;在这两类绞刀上加装罩壳均能有效抑制底泥中污染物释放,特别是疏浚后1 h内营养盐氮释放;理想的绞吸式挖泥船环保功能改造方案为采用螺旋绞刀替换普通绞刀并加装罩壳（防扩散装置）。

Dredging simulation experiments were carried out using a general cutter, a housing-general cutter, a spiral cutter, and a housing-spiral cutter, in order to study the change of contaminant concentration in overlying water and compare the environmental performance of cutters with different structures. The results were as follows： dredging with the spiral cutter, the amount of released sediment contaminants was less than that with the general cutter; dredging with both the spiral cutter and the general cutter equipped with housings could effectively reduce the amount of released sediment contaminants, particularly the amount of released nutrient nitrogen one hour after dredging; and the ideal transformation scheme for a cutter suction dredger （CSD） in terms of its environment- friendly function is dredging with a spiral cutter equipped with an anti-diffusion device （housing）.