The objective of this work was to assess the impact of filamentous bacteria on the settling velocity and rheological behaviour of activated sludge. We then identified the relevant settling and rheological model parameters to account for the impact of filamentous bulking on the prediction of sludge mixing and transport in secondary settling tanks by a computational fluid dynamics (CFD) model. We...

Settling performance of operational amplifiers (opamps) is of great importance in analog signal-processing applications. Among different architectures, three-stage amplifiers are gaining more attention between analog circuit designers of modern technologies with small supply voltages where few devices can be stacked. Previous attempts to design and optimize a three-stage opamp based on settling...

The use of sediment settling velocity based on mineral grain size distribution in erosion models ignores the effects of aggregation on settling velocity. The alternative approach, wet-sieved aggregate size distribution, on the other hand, cannot represent all destructive processes that eroded soils may experience under impacting raindrops. Therefore, without considering raindrop impact, both me...

Exposure to highly toxic pesticides could potentially cause cancer and disrupt the development of vital systems. Monitoring activities were performed to assess the level of contamination; however, these were costly, laborious, and short-term leading to insufficient monitoring data. However, the performance of the existing Soil and Water Assessment Tool (SWAT model) can be restricted by its two-...

In this paper, the transient settling dynamics of a spherical particle sedimenting in a linearly stratified fluid is investigated by performing fully resolved direct numerical simulations. The settling behaviour is quantified for different values of Reynolds, Froude and Prandtl numbers. It is demonstrated that the transient settling dynamics is correlated to the induced Lagrangian drift of flow...

An experimental study is performed to measure the terminal settling velocities of spherical particles in surfactant based shear thinning viscoelastic (VES) fluids. The measurements are made for particles settling in unbounded fluids and fluids between parallel walls. VES fluids over a wide range of rheological properties are prepared and rheologically characterized. The rheological characteriza...

Coastal Louisiana is currently experiencing high rates of wetland loss and large-scale ecosystem restoration being implemented. One the largest most novel projects a controlled sediment diversion, proposed to rebuild sustain wetlands by diverting sediment- nutrient-rich water from Mississippi River. However, impact this diversion on nutrient budget receiving basin largely unknown. A quality mod...

A mathematical method for calculation of the minimum cross-sectional area of a thickener is presented by obtaining minimum laboratory batch settling test data, a function, which is called settling function, is derived. This function is found to be in the form of a polynomial of third order. The settling function and mass flux relation are used for the design of thickener. The method predict...