Ongoing research at the University of Leeds, being undertaken as part of the DIAMOND university consortium, is exploring the effectiveness of various ultrasonic technologies as in situ probes to characterize and monitor simulant nuclear wastes. Through use of a commercial Ultrasonic Velocity Profiler (UVP) and an Acoustic Backscatter Sensor (ABS) both with 1 – 5 MHz transducers, various propert...

The dissolution of CaCO(3) is one of the ways ocean acidification can, potentially, greatly affect the ballast of aggregates. A diminution of the ballast could reduce the settling speed of aggregates, resulting in a change in the carbon flux to the deep sea. This would mean lower amounts of more refractory organic matter reaching the ocean floor. This work aimed to determine the effect of ocean...

The settling velocities of natural, synthetic, and industrial particles were measured in a grid turbulence facility using optical measurement techniques. Particle image velocimetry and 2D particle tracking were used to measure the instantaneous velocities of the flow and the particles' trajectories simultaneously. We find that for particles examined in this study (Rep = 0.4-123), settling veloc...

Recovery of cellulose fibres from paper mill effluent has been studied using common polysaccharides or biopolymers such as Guar gum, Xanthan gum and Locust bean gum as flocculent. Guar gum is commonly used in sizing paper and routinely used in paper making. The results have been compared with the performance of alum, which is a common coagulant and a key ingredient of the paper industry. Guar g...

The most meaningful parameter to determine the treatment efficiency of large scale sedimentation tanks is the settling velocity of suspended solids. However it is difficult to measured representative settling velocity because of the instability of suspended solids. A water elutriation system was tested to assess the treatment efficiency of sedimentation tanks. In laboratory tests the flow condi...

Motivated by field studies of the Ems estuary which show longitudinal gradients in bottom sediment concentration as high as O(0.01 kg/m), we develop an analytical model for estuarine residual circulation based on currents from salinity gradients, turbidity gradients, and freshwater discharge. Salinity is assumed to be vertically well mixed, while the vertical concentration profile is assumed to...