Dredging

About: Dredging is a research topic. Over the lifetime, 3300 publications have been published within this topic receiving 28325 citations.

Sediment Dredging, Treatment and Disposal

Abstract: Removal of contaminated sediments from the water body with subsequent treatment and/or disposal of the contaminated dredged sediment is the most common approach for contaminated sediment remediation. Various excavation equipment types and approaches have been used, including both dredging (excavation underwater) and excavation of the sediments in the dry. Excavation can be used as the sole active remediation approach or can be used in combination with monitored natural recovery (MNR) and/or capping. This chapter focuses primarily on environmental dredging as a contaminated sediment remedy component. The various treatment and disposal options available for contaminated sediments are also described in this chapter with a description of how they relate to the environmental dredging process, but these options are not covered in detail.

Environmental Dredging on the Birmingham Canals: Water Quality and Sediment Treatment

Abstract: Sediments in sections of the central Birmingham canals are heavily contaminated with heavy metals and mineral oils. The sediments promote high levels of metals within the water column, which suppress the establishment of aquatic vegetation and fisheries. Sediment disturbance by boat traffic results in the release of mineral oils which cause unsightly surface oil sheens. Studies into a variety of treatment methods indicated that removal and ex-situ treatment of the contaminated sediments would significantly improve water quality and result in environmental benefits. Funding from Birmingham City Council and British Waterways enabled the award of a contract with a value of approximately £800000 and commencement in February 1993 for the removal and processing of about 24 000 m3 of sediments by soil washing prior to off-site disposal. The nature of the sediments and water are reviewed, and the results of the soils washings are discussed. The impact of the dredging operations on water quality was monitored during the works and generally observed to be localized. An environmental management plan is now being implemented and the objectives for this are discussed.

Numerical Simulation of Deep-Sea Sediment Transport Induced by a Dredge Experiment in the Northeastern Pacific Ocean

Abstract: Predictability of the dispersion of sediment plumes induced by potential deep-sea mining activities is still very limited due to operational limitations on in-situobservations required for a thorough validation and calibration of numerical models. Here we report on a plume dispersion experiment carried out in the German license area for the exploration of polymetallic nodules in the northeastern tropical Pacific Ocean in 4200 m water depth. The dispersion of a sediment plume induced by a small-scale dredge experiment in April 2019 was investigated numerically by employing a sediment transport module coupled to a high-resolution hydrodynamic regional ocean model. Various aspects including sediment characteristics and ocean hydrodynamics were examined to obtain the best statistical agreement between sensor-based observations and model results. Results show that the model is capable of reproducing suspended sediment concentration and redeposition patterns observed during the dredge experiment. Due to a strong southward current during the dredging, the model predicts no sediment deposition and plume dispersion north of the dredging tracks. The sediment redeposition thickness reaches up to 9 mm directly next to the dredging tracks and 0.07 mm in about 320 m away from the dredging center. The model results suggest that seabed topography and variable sediment release heights above the seafloor cause significant changes especially for the low sedimentation pattern in the far-field area. Near bottom mixing is expected to strongly influence vertical transport of suspended sediment.

Remote-controlled submersible dredging vehicle

Abstract: The utility model relates to a remote-controlled submersible dredging vehicle-a mechanism device which is used for dredging the silt of rivers, or ditches or other water systems. The mechanism device is composed of a chassis, a power mechanism, an operating mechanism, a running mechanism, a control system and an auxiliary mechanism; the power mechanism, the operating mechanism, the running mechanism, the control system and the auxiliary mechanism are installed on the chassis. The remote-controlled submersible dredging vehicle walks by making use of crawler belts; the remote-controlled submersible dredging vehicle is provided with a lightening floating canister; a screw agitating and sucking device is fixed on a supporting frame. The sludge which is agitated up is conveyed to the inlet of a mud pump by a rotating screw reamer, and conveyed to a bank through a mud pump pipe. When the utility model dives to the bottom of a river to work, the action of walking, turning, mud mix, mud sucking, mud spouting, etc. of the remote-controlled submersible dredging vehicle can be remotely controlled. The utility model has the advantages of flexible operation, high dredging efficiency, etc.