Influencing factors for dewatering efficiency of plate and frame filterpressing for sediment

With the advancement of ecological dredging projects, the amount of dredged sediment has increases year by year. In order to realize the rapid dewatering of sediment with high water content, the plate and frame filter pressing dewatering is often used to deal with dredged sediment in the projects. At present, most of the researches mainly focus on the influences of flocculant types and dosages on the subsequent dewatering effects of the plate and frame filter pressing, and few researches on the characteristics of sediment plate and frame filter pressing in terms of the setting of construction process parameters. The influences of process parameters on the dewatering effects of the plate and frame filter pressing are systematically studied from three aspects: feed time, feed pressure and filter cloth aperture. The results show that when the water content of sediment is 4 W_L, the forming effects of mud cake are better when the feed time is 120 min. After the feed pressure is more than 0.5 MPa, the growth of mud cake dewatering tends to be flat, indicating that the further increase of pressure has a limited effect on the enhancement of the dewatering efficiency. In addition, when the filter cloth aperture D of the filter cloth is set to be 8~16 times the median particle size d₅₀ of the sediment, the dewatering amount reaches the maximum value. By finely regulating the parameters of the plate and frame filter pressing process, this study can provide an important theoretical basis and technical guidance for similar engineering practice.