Abstract
Some physical properties of suspended solids in two trickling filter effluents were measured. Several size indices and shape factors of these particles were determined with the use of an image analysis system. The applicability of the sample preservation technique limited the studied particles to those with the longest dimension greater than 10 μm. The majority of the particles studied had diameters of less than 100 μm.
The settling velocities and the sizes of the particles studied were measured in a quiescent water column by a multiexposure photographic technique. Results showed that particle settling velocity increased as a fractional power of size. Based on these direct measurements, the particle density was calculated, and found to decrease with an increase of the particle size.