Experimental Research on Flocculating Dewatering for Sediment Dredged in Typical River Sections on Chongming Island

At present,high water content is the most bottleneck of resource utilization of river dredging sediment.With the dredging sediments in Laoxiao River(Sediment C) and East lake of Yingdong village in Chongming Island(Sediment Y) as the objects of study, the paper represented a research on settling and dehydrating effects of the three flocculating agents on different dredging sediments, which provides basis for the choice of optimum flocculating agent,and the experiments on different doses of flocculating agent,water contents,flocculating times and stirring intensities,providing the optimum parameters for practical projects.The results show that,the settling effect of 1# flocculating agents on sediment C is the best,3# on sediment Y is the best,and the doses of them are 2%and 1 %(percent of dried sediment)respectively,the optimum water contents of sediment C and Y for dredging are 380.0%and 305.0%, the optimum stirring intensities are 80 rpm and 40 rpm respectively,and the flocculating time are 30 min for both of them.