Seed-sediment Dynamics: An experimental study into the behaviour of seagrass seeds in a sand mixture informing a novel approach for large scale seagrass restoration

<br/>In response to the sharp decline of seagrass globally, various restoration techniques have been developed and applied; many at limited scale and with limited success. This research focuses on the fluid mechanics and behaviour of seagrass seeds in a sand mixture through physical laboratory experiments. The objective is to establish a...

The effects of ionic strength and surface charge on O/W emulsion fouling of ceramic membranes quantified via DLVO and XDLVO models

Large amounts of oily wastewater which included oil-in-water (O/W) emulsions, also known as produced water (PW), were produced in tandem with the enhanced oil recovery (EOR). Ultrafiltration (UF) was an effective and economic method to separate micron-sized O/W emulsions, while the membrane fouling limited its development. Understanding the...

Cohesive Sediment Erosion Induced By Coandă-Effect-Based Polymetallic-Nodule Collector: Small-scale experiments

The increasing demand for rare minerals, such as lithium, cobalt, and copper, driven by the growth of the world population and the transition towards sustainable energy technologies, has become a pressing concern. These minerals are crucial for electrifying the transportation sector through electric vehicle production and are in high demand for...

Fouling control in ceramic nanofiltration membrane by pre-coating with calcium carbonate

Water scarcity and uneven distribution of water resources pose a significant challenge globally. Searching for alternative water resources could alleviate this issue. Municipal sewage reclamation with ceramic NF membrane has gained momentum nowadays. However, the inevitable fouling, especially organic fouling during membrane filtration, is the...

A DNS study of the rheology of dense suspensions in plane Couette flow

Dense suspensions can be found in various industrial and natural processes. A relatively new technique uses the principle of additive manufacturing to produce products from a wide variety of materials by printing with dense suspensions. To reach a high print quality the suspension rheology must be understood very well. Current knowledge about...

Microparticle Swarms - Faster Together: The Effect of Particle Concentration on Colloidal Transport in Fractured and Porous Media

Colloidal particle swarms can show settling velocities over a thousand times as fast as that of a single particle. The transport of colloidal particles is thus strongly affected by the formation and behaviour of these particle swarms, which could have important implications for the widespread use and prevalence of colloidal particles. Swarming...

An extended multiphase drift-flux model with a discretized form of population balance equations for flocculation and settling process of cohesive sediment in deep-sea mining plumes

To meet energy demand towards a low-carbon future, the global market demand is growing for metals such as cobalt and nickel which are major elements in batteries. Polymetallic nodules, which are formed on abyssal plains at depths ranging from 4 to 6 kilometres and are distributed in high abundance on the top of the seabed, contains several times...

Hydrodynamic Modeling of Estuarine Clay Mineral Distribution: The Ravenglass Estuary Analogue

Plume dispersion of low-density clayey suspension turbidity currents created by deep-sea mining

Due to the increased demand for materials like cobalt and nickel, there is an interest to mine polymetallic nodules from the deep-sea. These nodules are abundantly distributed along the abyssal plains, e.g., the Clarion Clipperton Zone (CCZ) in the North East Pacific. These nodules lay spread on top of a seabed consisting of very fine clayey...

The hydrodynamics of an eco-innovative sediment reuse project in the Rotterdam Waterway: Gaining insight into the physics and the predictive capability of two operational hydrodynamic models

Phenomena like sea level rise, global warming and erosion together contribute to increasing flood risk in vulnerable coastal areas. As this flood risk increases, initiatives to mitigate the effects of climate change in the coastal zone are also increasingly sought. During recent years, the view that these measures should be circular has gained...

Fouling Control in Ceramic Nanofiltration Membrane: Forward Flush and Precoating Method

The new concept of sewer mining which utilizes the ceramic nanofiltration (C-NF) membranes offers a compact solution for water and other resources recovery. However, since it has very limited pre-treatment process, membrane fouling is a common problem due to the direct contact between the membrane and sewage water. Sewage water contains a lot of...

Dewaterability of thermophilic digestate: Characteristics and underlying processes: A heuristic comparison of mesophilic digestion, thermophilic digestion and digestate ammonia stripping on the site of Bath WWTP, Netherlands

In a WWTP operating with full scale mesophilic digestion, a thermophilic digestion pilot and a digestate ammonia stripping pilot were installed. Benefits of the aforementioned sludge treatment processes, such as energy and nutrient recovery, are extensively recognized. However, drawbacks, such as deficient sludge dewatering, are amply...

Spreading of polluted sediment around the U-864 wreck: Analyses of currents and sediment dispersal during installation of a capping layer using a fexible fallpipe vessel

Four kilometers west of the Norwegian island Fedje, mercury, leaking from the U-864 wreck, has highly polluted a seabed area of approximately 40 000 m2. The bow section of the wreck is located on a stability critical slope of 15 degrees. In 2016, Van Oord used a flexible fall pipe system to install a counter fill to stabilize the wreck and...

Effect of movement on the settlement of fluid mud: None

This thesis describes the research about the effect of movement on fluid mud. This was done by exposing several samples of fluid mud from the port of Hamburg to different types of movement for an extended amount of time. It was found that when fluid mud is exposed to kinetic energy of the type used in this experiment, particles will arrange...