Settling velocities of fractal aggregates
Article Abstract:
Particle settling is an important aspect of water and wastewater treatment processes. It has been suggested that microbial aggregates generated by these processes are fractal and therefore, have different settling velocities. An investigation of the settling velocities of impermeable spherical aggregates generated from dyed latex microspheres in standard paddle mixers shows that fractal aggregates settle about four to eight times faster than velocities predicted using an impermeable sphere model, also known as Stoke's law.
Publication Name: Environmental Science & Technology
Subject: Science and technology
ISSN: 0013-936X
Year: 1996
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Collision frequencies between fractal aggregates and small particles in a turbulently sheared fluid
Article Abstract:
A model was developed to measure the collision frequency between fractal aggregates and microspheres in turbulent shear conditions. The model was developed after results of modeling using both the rectilinear collision model and the curvilinear model failed to accurately model the kinetics of particle coagulation by shear motion. The rectilinear model overpredicted the particle collisions and curvilinear models underestimated the collision frequency function for highly porous aggregates.
Publication Name: Environmental Science & Technology
Subject: Science and technology
ISSN: 0013-936X
Year: 1997
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Collision frequencies of fractal aggregates with small particles by differential sedimentation
Article Abstract:
Fractal mathematics and the filtration theory were used to generate a fractal collision model that calculates the collision frequency functions between settling fractal aggregates and small particles, as well as the capture efficiencies of the small particles by the aggregates. The fractal collision model is then compared with the permeability model based on a homogenous distribution of primary particles within the aggregates, the curvilinear model and the rectilinear collision model.
Publication Name: Environmental Science & Technology
Subject: Science and technology
ISSN: 0013-936X
Year: 1997
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