Concurrent disposal and consolidation of dredged sediment using horizontal drains and vacuum loading

摘要

A method and system for dewatering and consolidating contaminated dredged sediment concurrently as it is discharged to a disposal pond using horizontal drains installed in the settled sediment and vacuum loading. Horizontal drains are connected to a vacuum pump via collector hoses and a header pipe. Vacuum pump operation consolidates the settled sediment and reduces the volume, enabling continued discharge of dredged sediment. Successive installation of horizontal drains within accumulating sediment and consolidation by vacuum pumping may continue until the disposal pond is filled with consolidated sediment. Vacuum pumping is continued for some period after final cover installation to enhance containment performance by over-consolidation. The horizontal drain system may also be used to deliver liquid reagents for sediment treatment or to circulate water for flushing. The method enables the disposal pond to be on land or under water below the original sediment line.