EXPERIMENTAL STUDY ON FLOCCULATION DEHYDRATION OF DREDGED SEDIMENT

Focusing on the problems of high-water content, strong compressibility and difficult dehydration of dredged sediment, this paper used polymer flocculants to conduct sediment-water separation tests. We found that the cationic polyacrylamide has the best flocculation effect on the sediment-water separation, and the optimal dosage of polyaluminum ferric chloride, anionic polyacrylamide and cationic polyacrylamide were 5 g/L, 2 g/L and 1 g/L respectively. The zeta potential decreased with increasing the dosages of polyaluminum ferric chloride and cationic polyacrylamide and increased with increasing the dosage of anionic polyacrylamide. And it is also concluded that cationic polyacrylamide has the most obvious effect on the increase in sediment particle size, followed by anionic polyacrylamide and polyaluminum ferric chloride. The water content in each part of the flocculated sediment varies greatly, the lowest is in the bottom, followed by the middle, and the highest is in the upper.